In colon cancer surgery,ensuring the complete removal of the primary tumor and draining lymph nodes is crucial.Lymphatic drainage in the colon follows the vascular supply,typically progressing from pericolic to paraao...In colon cancer surgery,ensuring the complete removal of the primary tumor and draining lymph nodes is crucial.Lymphatic drainage in the colon follows the vascular supply,typically progressing from pericolic to paraaortic lymph nodes.While NCCN guidelines recommend the removal of 10-12 lymph nodes for ade-quate oncological resection,achieving complete oncological resection involves more than just meeting these numerical targets.Various techniques have been developed and studied over time to attain optimal oncological outcomes.A key technique central to this goal is identifying the ileocolic vessels at their origin from the superior mesenteric vessels.Complete excision of the visceral and parietal mesocolon ensures the intact removal of the specimen,while D3 lymphade-nectomy targets all draining regional lymph nodes.Although these principles emphasize different aspects,they ultimately converge to achieve the same goal of complete oncological resection.This article aims to simplify the surgical steps that align with the principle of central vascular ligation and mesocolon mobilization while ensuring adequate D3 dissection.展开更多
Pulmonary arterial hypertension PAH is a progressive disease characterized by an increase in pulmonary arterial pressure and resistance. It often complicates congenital heart disease with a left-to-right shunt. The ob...Pulmonary arterial hypertension PAH is a progressive disease characterized by an increase in pulmonary arterial pressure and resistance. It often complicates congenital heart disease with a left-to-right shunt. The objective of this study is to evaluate the evolutionary profile of the pulmonary pressures of children with congenital heart disease with left-to-right shunt and to identify the factors favoring an evolution towards PAH. This is a retrospective, descriptive and analytical study over a period of four years and six months (from January 1, 2016 to June 30, 2020) at the Center National d’Enfant Albert Royer in Dakar on a series of 87 cases. The hospital frequency was 3.98 per thousand, and the incidence of PAH was 9.44%. The sex ratio of 0.74. The average age was 44.76 months. The average time between the onset of symptoms and the diagnosis of heart disease is 78.81 days. Dyspnea was found in 70.11% of cases, the burst of pulmonary B2 was found in 55%. Global heart failure was noted in 39.08% of cases. Cardiomegaly was found in 89.66% and pulmonary hypervascularization was found in 57.72% of cases. CIV was present in 54.02% of cases, followed by PCA in 21.14% and CAVc in 18.39% of cases. furosemide was used in 97.70% of cases and Captopril in 74.71% of cases. Sildenafil was used in 10.34% of patients, and 12.64% of patients benefited from surgical management. Eisenmenger syndrome was found in 12.64% of patients. PAH in these heart diseases is a formidable and frequent complication, due to an increase in precapillary flow. The major improvement in mortality and morbidity is early surgical management, in the first months of life, to prevent pulmonary vascular disease.展开更多
BACKGROUND Unroofed coronary sinus(UCS)is a rare subtype of atrial septal defect.It is frequently associated with a persistent left superior vena cava and is often part of a more intricate cardiac malformation.CASE SU...BACKGROUND Unroofed coronary sinus(UCS)is a rare subtype of atrial septal defect.It is frequently associated with a persistent left superior vena cava and is often part of a more intricate cardiac malformation.CASE SUMMARY This report describes a rare case of an adolescent patient with UCS featuring atrial situs solitus,absence of the right superior vena cava and a persistent left superior vena cava draining into the left atrium consistent with total unroofing of the coronary sinus.This was associated with concurrent severe mitral insufficiency secondary to redundant and prolapsing leaflets,and a substantial left-to-right shunt across the coronary sinus orifice.A comprehensive examination of the existing literature is included,shedding light on the diagnostic challenges of UCS and describing the available surgical options within the context of mitral valve surgery.CONCLUSION UCS is a complex condition requiring careful consideration of associated anomalies and a tailored surgical approach.展开更多
Right-sided colon cancers (RCC) and left-sided colon cancers (LCC) have different epidemiological, physiological, pathological, genetic, and clinical characteristics, which result in differences in the course, prognos...Right-sided colon cancers (RCC) and left-sided colon cancers (LCC) have different epidemiological, physiological, pathological, genetic, and clinical characteristics, which result in differences in the course, prognosis, and outcome of disease. The objective of our study is to compare right-sided colon cancers and left-sided colon cancers regarding clinicopathological and survival characteristics. This is a retrospective study of 664 patients with colon cancer treated at the medical oncology department of Fez over a period from December 2009 to September 2020. Rectosigmoid, descending colon, and splenic flexure tumors were considered left-sided colon cancers, whereas ascending colon tumors were considered right-sided colon cancers. The Kaplan Meier method was used to estimate median survival. The study included 664 patients (female, 47%) having colon cancer with a median age of 60 years (23 - 83). Of the patients, 78.5% (n = 519) had LCC and 19.36 % (n = 128) had RCC. The rate of patients aged ≥ 65 years and the rate of patients with a family history of colon cancer was higher in the LCC patients. The proportion of poorly differentiated adenocarcinomas represented 3%, of which 63% had cancer of the right colon. There was a significantly higher proportion of higher T stage (T3-4: 62% vs 38%) in right sided tumors as compared to left sided tumors. The rate of metastatic patients was 64.1% in the RCC group and 43% in the LCC group. The median follow-up period was 14 months in the RCC group and 19 months in the LCC group with higher median overall survival in the LCC group (32 vs 21 months). We found histopathological differences between right and left sided colon cancer. Tumors on the right colon were found to be more aggressive, as expressed by poorer differentiation, higher T stage associated with a median overall survival better in left colon cancer.展开更多
The colon is derived from the embryological midgut and hindgut separately,with the right colon and left colon having different features with regards to both anatomical and physiological characteristics.Cancers located...The colon is derived from the embryological midgut and hindgut separately,with the right colon and left colon having different features with regards to both anatomical and physiological characteristics.Cancers located in the right and left colon are referred to as right colon cancer(RCC) and left colon cancer(LCC),respectively,based on their apparent anatomical positions.Increasing evidence supports the notion that not only are there differences in treatment strategies when dealing with RCC and LCC,but molecular features also vary between them,not to mention the distinguishing clinical manifestations.Disease-free survival after radical surgery of both RCC and LCC are similar.In the treatment of RCC,the benefit gained from adjuvant FOLFIRI chemotherapy is superior,or at least similar,to LCC,but inferior to LCC if FOLFOX regimen is applied.On the other hand,metastatic LCC exhibits longer survival than that of RCC in a palliative chemotherapy setting.For KRAS wild-type cancers,LCC benefits more from cetuximab treatment than RCC.Moreover,advanced LCC shows a higher sensitivity to bevacizumab treatment in comparison with advanced RCC.Significant varieties exist at the molecular level between RCC and LCC,which may serve as the cause of all apparent differences.With respect to carcinogenesis mechanisms,RCC is associated with known gene types,such as MMR,KRAS,BRAF,and mi RNA-31,while LCC is associated with CIN,p53,NRAS,mi RNA-146 a,mi RNA-147 b,and mi RNA-1288.Regarding protein expression,RCC is related to GNAS,NQO1,telomerase activity,P-PDH,and annexin A10,while LCC is related to Topo I,TS,and EGFR.In addition,separated pathways dominate progressionto relapse in RCC and LCC.Therefore,RCC and LCC should be regarded as two heterogeneous entities,with this heterogeneity being used to stratify patients in order for them to have the optimal,current,and novel therapeutic strategies in clinical practice.Additional research is needed to uncover further differences between RCC and LCC.展开更多
Aim of the study is to comprehensively review the latest trends in laparoscopic complete mesocolic excision(CME) with central vascular ligation(CVL) for the multimodal management of right colon cancer. Historical and ...Aim of the study is to comprehensively review the latest trends in laparoscopic complete mesocolic excision(CME) with central vascular ligation(CVL) for the multimodal management of right colon cancer. Historical and up-to-date anatomo-embryological concepts are analyzed in detail,focusing on the latest studies of the mesenteric organ,its dissection by mesofascial and retrofascial cleavage planes,and questioning the need for a new terminology in colonic resections. The rationale behind Laparoscopic CME with CVL is thoroughly investigated and explained. Attention is paid to the current surgical techniques and the quality of the surgical specimen,yielded through mesocolic,intramesocolic and muscularis propria plane of surgery. We evaluate the impact on long term oncologic outcome in terms of local recurrence,overall and disease-free survival,according to the plane of resection achieved. Conclusions are drawn on the basis of the available evidence,which suggests a pivotal role of laparoscopic CME with CVL in the multimodal management of right sided colonic cancer: performed in the right mesocolic plane of resection,laparoscopic CME with CVL demonstrates better oncologic results when compared to standard non-mesocolic planes of surgery,with all the advantages of laparoscopic techniques,both in faster recovery and better immunological response. The importance of minimally invasive mesoresectional surgery is thus stressed and highlighted as the new frontier for a modern laparoscopic total right mesocolectomy.展开更多
AIM To analyze the outcomes of living-donor liver transplantation(LDLT) using left-lobe(LL) or right-lobe(RL) small-for-size(SFS) grafts.METHODS Prospectively collected data of adult patients who underwent LDLT at our...AIM To analyze the outcomes of living-donor liver transplantation(LDLT) using left-lobe(LL) or right-lobe(RL) small-for-size(SFS) grafts.METHODS Prospectively collected data of adult patients who underwent LDLT at our hospital in the period from January 2003 to December 2013 were reviewed. The patients were divided into the RL-LDLT group and the LL-LDLT group. The two groups were compared in terms of short-and long-term outcomes, including incidence of postoperative complication, graft function, graft survival, and patient survival. A SFS graft was defined as a graft with a ratio of graft weight(GW) to recipient standard liver volume(RSLV)(GW/RSLV) of < 50%. The Urata formula was used to estimate RSLV.RESULTS Totally 218 patients were included for analysis, with 199 patients in the RL-LDLT group and 19 patients in the LL-LDLT group. The two groups were similar in terms of age(median, 53 years in the RL-LDLT group and 52 years in the LL-LDLT group, P = 0.997) but had significantly different ratios of men to women(165:34 in the RL-LDLT group and 8:11 in the LL-LDLT group, P < 0.0001). The two groups were also significantly different in GW(P < 0.0001), GW/RSLV(P < 0.0001), and graft cold ischemic time(P = 0.007). When it comes to postoperative complication, the groups were comparable(P = 0.105). Five patients died in hospital,4(2%) in the RL-LDLT group and 1(5.3%) in the LLLDLT group(P = 0.918). There were 38 graft losses, 33(16.6%) in the RL-LDLT group and 5(26.3%) in the LL-LDLT group(P = 0.452). The 5-year graft survival rate was significantly better in the RL-LDLT group(95.2% vs 89.5%, P = 0.049). The two groups had similar 5-year patient survival rates(RL-LDLT: 86.8%, LL-LDLT: 89.5%, P = 0.476).CONCLUSION The use of SFS graft in LDLT requires careful tailormade surgical planning and meticulous operation. LLLDLT can be a good alternative to RL-LDLT with similar recipient outcomes but a lower donor risk. Further research into different patient conditions is needed in order to validate the use of LL graft.展开更多
In this study, we investigated the changes in the right-to-left shunt (RLS) of the patent foramen ovale (PFO) at different phases of the Valsalva maneuver and analyzed the possible mechanisms. The study population con...In this study, we investigated the changes in the right-to-left shunt (RLS) of the patent foramen ovale (PFO) at different phases of the Valsalva maneuver and analyzed the possible mechanisms. The study population consisted of 57 patients with symptoms highly suggestive of a PFO. These patients had been diagnosed with apsychia, migraine with aura, cerebral infarction, transient ischemic attack (TIA), and cerebral ischemia with unknown cause. Routine echocardiography was performed in all patients to rule out a cardiac malformation. Contrast-transcranial Doppler (c-TCD) and contrast-enhanced transthoracic echocardiography (c-TTE) were used to visualize and quantify the RLS. The standard apical four chamber view was used to observe the changes of E peak, A peak, and velocity-time integral (VTI) ratio of tricuspid blood flow during the strain phase and release phase of the Valsalva maneuver. Paired t-test was used to compare E peak, A peak, and VTI ratio of tricuspid blood flow during the different phases. The right-to-left shunt across the PFO (PFO-RLS) was graded in the two phases and compared by Kruskal-Wallis test. Compared with the strain phase of the Valsalva maneuver, the parameters of E, A, and VTI in diastolic period in patients with PFO-RLS at the release phase were significantly increased [54.30 ± 13.65 cm/s vs 100.35 ± 21.11 cm/s, 42.21 ± 12.32 cm/s vs 57.30 ± 18.88 cm/s, 10.34 ± 3.27 cm/s vs 19.58 ± 4.56 cm/s, respectively], and the difference was statistically significant. The positive consequence of PFO-RLS, as diagnosed by c-TTE with the Valsalva maneuver at the release phase of the Valsalva maneuver, was significantly higher than that at the strain phase of the Valsalva maneuver. At the beginning of release phase of the Valsalva maneuver, decreased intrathoracic pressure led to increased venous backflow into the right atrium. Thus, high-velocity blood flow rapidly pushed the PFO open, which resulted in a significant increase in the PFO-RLS. Therefore, the increase of the PFO-RLS during the Valsalva maneuver is caused by the impact of high-velocity blood flow the PFO.展开更多
Background: The association of right coronary artery (RCA) stenosis in patients undergoing myocardial revascularization for left main coronary artery (LMCA) stenosis affects the prognosis. This study aimed to compare ...Background: The association of right coronary artery (RCA) stenosis in patients undergoing myocardial revascularization for left main coronary artery (LMCA) stenosis affects the prognosis. This study aimed to compare immediate results of patients with isolated LMCA stenosis and those with combined RCA stenosis. Patients and methods: We retrospectively evaluated 107 consecutive patients with LMCA disease who underwent coronary artery bypass grafts. The patients were divided into two groups: isolated LMCA stenosis (n = 36) and LMCA stenosis + RCA stenosis (n = 71). Different variables (preoperative, intra operative and post operative) were compared. Results: Patients with LMCA stenosis + RCA stenosis experienced higher prevalence of diabetes mellitus (p = 0.024) and smoker (p = 0.032). Also left ventricular EF was reduced (p = 0.004). Myocardial revascularization was more complete in patients with LMCA stenosis + RCA stenosis (p = 0.033), but in-hospital mortality rate was higher (12.6% vs 5.5%) in isolated LLMCA stenosis, but it did not reach statistical significance (p = 0.32). Except low output syndrome (LOS) that was frequent in presence of RCA stenosis (p = 0.026), no significant difference was found between groups for other complications. Conclusion: The presence of RCA stenosis in patients undergoing CABG for LMCA disease increases 30 day mortality but without significant impact on overall morbidities.展开更多
Presented in this paper are 3 cases of hemorrhage of ascending aorta and left ventricle after open heart surgery treated by extracardial bypass in our hospital from Oct. 1994 to Dec. 1995. Remained aneurysmal wall enc...Presented in this paper are 3 cases of hemorrhage of ascending aorta and left ventricle after open heart surgery treated by extracardial bypass in our hospital from Oct. 1994 to Dec. 1995. Remained aneurysmal wall enclosing conduit graft was used as a sac bypassed to right atrium to form a extracardial left-toright shunt in order to control bleeding and the results turned out to be satisfactory. The bypass and hemodynamically ignorable shunt can close spontaneously without complications with recovery of coagulation system. The technique may find wide application in clinical practice.展开更多
BACKGROUND Colorectal cancer(CRC)accounts for 9.4%of overall cancer deaths,ranking second after lung cancer.Despite the large number of factors tested to predict their outcome,most patients with similar variables show...BACKGROUND Colorectal cancer(CRC)accounts for 9.4%of overall cancer deaths,ranking second after lung cancer.Despite the large number of factors tested to predict their outcome,most patients with similar variables show big differences in survival.Moreover,right-sided CRC(RCRC)and left-sided CRC(LCRC)patients exhibit large differences in outcome after surgical intervention as assessed by preoperative blood leukocyte status.We hypothesised that stronger indexes than circulating(blood)leukocyte ratios to predict RCRC and LCRC patient outcomes will result from combining both circulating and infiltrated(tumour/peritumour fixed tissues)concentrations of leukocytes.AIM To seek variables involving leukocyte balances in peripheral blood and tumour tissues and to predict the outcome of CRC patients.METHODS Sixty-five patients diagnosed with colon adenocarcinoma by the Digestive Surgery Service of the La Paz University Hospital(Madrid,Spain)were enrolled in this study:43 with RCRC and 22 with LCRC.Patients were followed-up from January 2017 to March 2021 to record overall survival(OS)and recurrence-free survival(RFS)after surgical interventions.Leukocyte concentrations in peripheral blood were determined by routine laboratory protocols.Paraffin-fixed samples of tumour and peritumoural tissues were assessed for leukocyte concentrations by immunohistochemical detection of CD4,CD8,and CD14 marker expression.Ratios of leukocyte concentration in blood and tissues were calculated and evaluated for their predictor values for OS and RFS with Spearman correlations and Cox univariate and multivariate proportional hazards regression,followed by the calculation of the receiver-operating characteristic and area under the curve(AUC)and the determination of Youden’s optimal cutoff values for those variables that significantly correlated with either RCRC or LCRC patient outcomes.RCRC patients from the cohort were randomly assigned to modelling and validation sets,and clinician-friendly nomograms were developed to predict OS and RFS from the respective significant indexes.The accuracy of the model was evaluated using calibration and validation plots.RESULTS The relationship of leukocyte ratios in blood and peritumour resulted in six robust predictors of worse OS in RCRC:CD8+lymphocyte content in peritumour(CD8pt,AUC=0.585,cutoff<8.250,P=0.0077);total lymphocyte content in peritumour(CD4CD8pt,AUC=0.550,cutoff<10.160,P=0.0188);lymphocyte-to-monocyte ratio in peritumour(LMRpt,AUC=0.807,cutoff<3.185,P=0.0028);CD8+LMR in peritumour(CD8MRpt,AUC=0.757,cutoff<1.650,P=0.0007);the ratio of blood LMR to LMR in peritumour(LMRb/LMRpt,AUC=0.672,cutoff>0.985,P=0.0244);and the ratio of blood LMR to CD8+LMR in peritumour(LMRb/CD8MRpt,AUC=0.601,cutoff>1.485,P=0.0101).In addition,three robust predictors of worse RFS in RCRC were found:LMRpt(AUC=0.737,cutoff<3.185,P=0.0046);LMRb/LMRpt(AUC=0.678,cutoff>0.985,P=0.0155)and LMRb/CD8MRpt(AUC=0.615,cutoff>1.485,P=0.0141).Furthermore,the ratio of blood LMR to CD4+LMR in peritumour(LMRb/CD4MRpt,AUC=0.786,cutoff>10.570,P=0.0416)was found to robustly predict poorer OS in LCRC patients.The nomograms showed moderate accuracy in predicting OS and RFS in RCRC patients,with concordance index of 0.600 and 0.605,respectively.CONCLUSION Easily obtainable variables at preoperative consultation,defining the status of leukocyte balances between peripheral blood and peritumoural tissues,are robust predictors for OS and RFS of both RCRC and LCRC patients.展开更多
BACKGROUND Complete mesocolic excision(CME)with central vascular ligation(CVL)was proposed by Hohenberger in 2009.The CME principle has gradually become the technical standard for colon cancer surgery.How to achieve C...BACKGROUND Complete mesocolic excision(CME)with central vascular ligation(CVL)was proposed by Hohenberger in 2009.The CME principle has gradually become the technical standard for colon cancer surgery.How to achieve CME with CVL in laparoscopic right hemicolectomy(LRH)is controversial,and a unified standard approach is not yet available.In recent years,the authors’team has integrated the theory of membrane anatomy,tried to combine the cephalic approach with the classic medial approach(MA)for technical optimization,and proposed a cranialmedial mixed dominant approach(CMA).AIM To explore the feasibility of operational approaches for LRH with CME.METHODS In this retrospective cohort study,the clinical data of 57 patients with right-sided colon cancer(TNM stage I,II,or III)who underwent LRH with CME from January 2016 to June 2020 were collected and summarized.There were 31 patients in the traditional MA group and 26 in the CMA group.RESULTS There were no significant differences in baseline data between the two groups.The operation was shorter and the number of lymph nodes dissected was higher in the CMA group than in the MA group,but there was no significant difference in the number of positive lymph nodes,intraoperative blood loss,postoperative exhaust time,feeding time,postoperative hospital stay or postoperative complication incidence.CONCLUSION Our study shows that the CMA is a safe and feasible procedure for LRH with CME and has a unique advantage.展开更多
Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the L...Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the LHM,the intensity self-bending due to its propagation in the RHM can be compensated.In particular,if the propagation distance in the RHM is equal to that in the LHM and the refractive index of the LHM is n L =-1,the transverse intensity distribution of the Airy beam can return to its original state.展开更多
Background: Transradial coronary angiography has established itself as safe alternative to transfemoral approach. Today, the artery of approach lies completely on the operator’s choice. The Right Radial Approach (RRA...Background: Transradial coronary angiography has established itself as safe alternative to transfemoral approach. Today, the artery of approach lies completely on the operator’s choice. The Right Radial Approach (RRA) has been a favorite for most of the interventional cardiologists due to the convenience in operating from the right side. The Left Radial Approach (LRA) has always been a neglected route. LRA does have many advantages over the right, the vascular anatomy being one of them. The aim of our study was to compare the right radial approach of diagnostic coronary angiography with left radial approach. Method: A total of 70 cases of Coronary Angiography (CAG) with normal Allen test and satisfying the inclusion criteria were prospectively observed and studied after randomly assigning them into two equal groups, LRA (Left Radial Approach) n = 35 and RRA (Right Radial Approach) n = 35. Multipurpose TIG (Tiger) catheter was used in both the approaches to catheterize the right as well as left coronary artery. Results: The access time, catheter manipulation time, procedure time, amount of contrast used, hospital stay, intensity of pain experienced, cost of the procedure and quality of coronary angiogram observed were statistically insignificant while the fluoroscopy time was slightly statistically significant which was independent to catheter manipulation time. Conclusions: The neglected Left Radial Approach to coronary angiography is as efficacious, safe and cost effective with reduction in arterial spasm complications when compared to the Right Radial Approach performed by multipurpose Tiger catheter.展开更多
AIM To explore the differences in the responses of left-sided colorectal cancer(LSCRC) and right-sided colon cancer(RSCC) to traditional Chinese medicine(TCM).METHODS Patients with postoperative stage I-III colorectal...AIM To explore the differences in the responses of left-sided colorectal cancer(LSCRC) and right-sided colon cancer(RSCC) to traditional Chinese medicine(TCM).METHODS Patients with postoperative stage I-III colorectal cancer(CRC) were enrolled and divided into the LSCRC with or without TCM and RSCC with or without TCM groups depending on the primary tumor side and TCM administration. Patients in the TCM group were given TCM for at least 6 mo. Our research adopted diseasefree survival(DFS) as the primary endpoint. We applied a Cox proportional hazards regression model for the multivariate factor analysis using Stata 12.0 and SPSS 22.0 software for data analysis.RESULTS Of the 817 patients included in our study, 617 had LSCRC(TCM group, n = 404; Non-TCM group, n = 213), and 200 had RSCC(TCM group, n = 132; NonTCM group, n = 68). The 6-year DFS for patients with LSCRC was 56.95% in the TCM group and 41.50% in the Non-TCM group(P = 0.000). For patients with RSCC, the 6-year DFS was 52.92% in the TCM group and 37.19% in the Non-TCM group(P = 0.003). Differences between LSCRC and RSCC were not statistically significant regardless of TCM ingestion.CONCLUSION Patients with either LSCRC or RSCC and who took TCM experienced longer DFS; furthermore, patients with RSCC benefited more from TCM in DFS.展开更多
Currently, there are two rituals coexist in the world:"taking the left for the upper"and"taking the right for the up?per". The former is usually taken in domestic affairs such as meetings, dinners,...Currently, there are two rituals coexist in the world:"taking the left for the upper"and"taking the right for the up?per". The former is usually taken in domestic affairs such as meetings, dinners, etc. while the latter enjoys an overwhelmingly fa?vor in the west and so that it becomes the international practice in every conceivable social activities. The paper intends to offer a deep explanation of the differences of two rituals with adequate evidence and examples in some specific situations, say different kinds of seat arrangement in various large and small meetings, respectively in China and the west. Then it follows to provide the underlying reasons for the differences from the perspective of cultural difference. It finds that different denotation of"left"and"right"in English and Chinese may shed some light on the understanding of the two different rituals.展开更多
A closed linear relation T in a Banach space X is called left(resp. right) Fredholm if it is upper(resp. lower) semi Fredholm and its range(resp. null space) is topologically complemented in X. We say that T is left(r...A closed linear relation T in a Banach space X is called left(resp. right) Fredholm if it is upper(resp. lower) semi Fredholm and its range(resp. null space) is topologically complemented in X. We say that T is left(resp. right) Browder if it is left(resp. right)Fredholm and has a finite ascent(resp. descent). In this paper, we analyze the stability of the left(resp. right) Fredholm and the left(resp. right) Browder linear relations under commuting Riesz operator perturbations. Recent results of Zivkovic et al. to the case of bounded operators are covered.展开更多
Levitation chassis, as an extremely important component of maglev vehicles, provides functions of transmitting levitation force and steering force, and directly affects the safety performance of the vehicle. Based on ...Levitation chassis, as an extremely important component of maglev vehicles, provides functions of transmitting levitation force and steering force, and directly affects the safety performance of the vehicle. Based on the vertical dynamics model of the levitation chassis, kinetic equations of the model are established, and a simulation program is designed to analyze the structural decoupling function of the chassis, especially under the influence of elastic constraints between the left and right modules, which are exclusively owned by maglev vehicles. A finite element model of the levitation chassis based on left-right decoupling is constructed. Analysis results of the model show that the mechanical properties of the chassis tailored for the vehicle meet the design requirements, and the stiffness and strength is adequate to bear the weight of the whole vehicle.展开更多
We present a case of the right aortic arch with kommerell diverticulum (KD) and aberrant left subclavian artery in a symptomatic 50-year-old patient with a calcification in the presumed attachment site of the ligament...We present a case of the right aortic arch with kommerell diverticulum (KD) and aberrant left subclavian artery in a symptomatic 50-year-old patient with a calcification in the presumed attachment site of the ligamentum arteriosum (LA) to the KD. In another 30-year-old male patient, the entire course of a calcified LA was demonstrated using multidetector row computed tomography.展开更多
文摘In colon cancer surgery,ensuring the complete removal of the primary tumor and draining lymph nodes is crucial.Lymphatic drainage in the colon follows the vascular supply,typically progressing from pericolic to paraaortic lymph nodes.While NCCN guidelines recommend the removal of 10-12 lymph nodes for ade-quate oncological resection,achieving complete oncological resection involves more than just meeting these numerical targets.Various techniques have been developed and studied over time to attain optimal oncological outcomes.A key technique central to this goal is identifying the ileocolic vessels at their origin from the superior mesenteric vessels.Complete excision of the visceral and parietal mesocolon ensures the intact removal of the specimen,while D3 lymphade-nectomy targets all draining regional lymph nodes.Although these principles emphasize different aspects,they ultimately converge to achieve the same goal of complete oncological resection.This article aims to simplify the surgical steps that align with the principle of central vascular ligation and mesocolon mobilization while ensuring adequate D3 dissection.
文摘Pulmonary arterial hypertension PAH is a progressive disease characterized by an increase in pulmonary arterial pressure and resistance. It often complicates congenital heart disease with a left-to-right shunt. The objective of this study is to evaluate the evolutionary profile of the pulmonary pressures of children with congenital heart disease with left-to-right shunt and to identify the factors favoring an evolution towards PAH. This is a retrospective, descriptive and analytical study over a period of four years and six months (from January 1, 2016 to June 30, 2020) at the Center National d’Enfant Albert Royer in Dakar on a series of 87 cases. The hospital frequency was 3.98 per thousand, and the incidence of PAH was 9.44%. The sex ratio of 0.74. The average age was 44.76 months. The average time between the onset of symptoms and the diagnosis of heart disease is 78.81 days. Dyspnea was found in 70.11% of cases, the burst of pulmonary B2 was found in 55%. Global heart failure was noted in 39.08% of cases. Cardiomegaly was found in 89.66% and pulmonary hypervascularization was found in 57.72% of cases. CIV was present in 54.02% of cases, followed by PCA in 21.14% and CAVc in 18.39% of cases. furosemide was used in 97.70% of cases and Captopril in 74.71% of cases. Sildenafil was used in 10.34% of patients, and 12.64% of patients benefited from surgical management. Eisenmenger syndrome was found in 12.64% of patients. PAH in these heart diseases is a formidable and frequent complication, due to an increase in precapillary flow. The major improvement in mortality and morbidity is early surgical management, in the first months of life, to prevent pulmonary vascular disease.
文摘BACKGROUND Unroofed coronary sinus(UCS)is a rare subtype of atrial septal defect.It is frequently associated with a persistent left superior vena cava and is often part of a more intricate cardiac malformation.CASE SUMMARY This report describes a rare case of an adolescent patient with UCS featuring atrial situs solitus,absence of the right superior vena cava and a persistent left superior vena cava draining into the left atrium consistent with total unroofing of the coronary sinus.This was associated with concurrent severe mitral insufficiency secondary to redundant and prolapsing leaflets,and a substantial left-to-right shunt across the coronary sinus orifice.A comprehensive examination of the existing literature is included,shedding light on the diagnostic challenges of UCS and describing the available surgical options within the context of mitral valve surgery.CONCLUSION UCS is a complex condition requiring careful consideration of associated anomalies and a tailored surgical approach.
文摘Right-sided colon cancers (RCC) and left-sided colon cancers (LCC) have different epidemiological, physiological, pathological, genetic, and clinical characteristics, which result in differences in the course, prognosis, and outcome of disease. The objective of our study is to compare right-sided colon cancers and left-sided colon cancers regarding clinicopathological and survival characteristics. This is a retrospective study of 664 patients with colon cancer treated at the medical oncology department of Fez over a period from December 2009 to September 2020. Rectosigmoid, descending colon, and splenic flexure tumors were considered left-sided colon cancers, whereas ascending colon tumors were considered right-sided colon cancers. The Kaplan Meier method was used to estimate median survival. The study included 664 patients (female, 47%) having colon cancer with a median age of 60 years (23 - 83). Of the patients, 78.5% (n = 519) had LCC and 19.36 % (n = 128) had RCC. The rate of patients aged ≥ 65 years and the rate of patients with a family history of colon cancer was higher in the LCC patients. The proportion of poorly differentiated adenocarcinomas represented 3%, of which 63% had cancer of the right colon. There was a significantly higher proportion of higher T stage (T3-4: 62% vs 38%) in right sided tumors as compared to left sided tumors. The rate of metastatic patients was 64.1% in the RCC group and 43% in the LCC group. The median follow-up period was 14 months in the RCC group and 19 months in the LCC group with higher median overall survival in the LCC group (32 vs 21 months). We found histopathological differences between right and left sided colon cancer. Tumors on the right colon were found to be more aggressive, as expressed by poorer differentiation, higher T stage associated with a median overall survival better in left colon cancer.
基金Supported by Grants from Key Projects in the National Science and Technology Pillar Program during the Twelfth Five-year Plan Period,No.2014BAI09B07grants from the National Natural Science Foundation of China,No.81101580 and No.81201640
文摘The colon is derived from the embryological midgut and hindgut separately,with the right colon and left colon having different features with regards to both anatomical and physiological characteristics.Cancers located in the right and left colon are referred to as right colon cancer(RCC) and left colon cancer(LCC),respectively,based on their apparent anatomical positions.Increasing evidence supports the notion that not only are there differences in treatment strategies when dealing with RCC and LCC,but molecular features also vary between them,not to mention the distinguishing clinical manifestations.Disease-free survival after radical surgery of both RCC and LCC are similar.In the treatment of RCC,the benefit gained from adjuvant FOLFIRI chemotherapy is superior,or at least similar,to LCC,but inferior to LCC if FOLFOX regimen is applied.On the other hand,metastatic LCC exhibits longer survival than that of RCC in a palliative chemotherapy setting.For KRAS wild-type cancers,LCC benefits more from cetuximab treatment than RCC.Moreover,advanced LCC shows a higher sensitivity to bevacizumab treatment in comparison with advanced RCC.Significant varieties exist at the molecular level between RCC and LCC,which may serve as the cause of all apparent differences.With respect to carcinogenesis mechanisms,RCC is associated with known gene types,such as MMR,KRAS,BRAF,and mi RNA-31,while LCC is associated with CIN,p53,NRAS,mi RNA-146 a,mi RNA-147 b,and mi RNA-1288.Regarding protein expression,RCC is related to GNAS,NQO1,telomerase activity,P-PDH,and annexin A10,while LCC is related to Topo I,TS,and EGFR.In addition,separated pathways dominate progressionto relapse in RCC and LCC.Therefore,RCC and LCC should be regarded as two heterogeneous entities,with this heterogeneity being used to stratify patients in order for them to have the optimal,current,and novel therapeutic strategies in clinical practice.Additional research is needed to uncover further differences between RCC and LCC.
文摘Aim of the study is to comprehensively review the latest trends in laparoscopic complete mesocolic excision(CME) with central vascular ligation(CVL) for the multimodal management of right colon cancer. Historical and up-to-date anatomo-embryological concepts are analyzed in detail,focusing on the latest studies of the mesenteric organ,its dissection by mesofascial and retrofascial cleavage planes,and questioning the need for a new terminology in colonic resections. The rationale behind Laparoscopic CME with CVL is thoroughly investigated and explained. Attention is paid to the current surgical techniques and the quality of the surgical specimen,yielded through mesocolic,intramesocolic and muscularis propria plane of surgery. We evaluate the impact on long term oncologic outcome in terms of local recurrence,overall and disease-free survival,according to the plane of resection achieved. Conclusions are drawn on the basis of the available evidence,which suggests a pivotal role of laparoscopic CME with CVL in the multimodal management of right sided colonic cancer: performed in the right mesocolic plane of resection,laparoscopic CME with CVL demonstrates better oncologic results when compared to standard non-mesocolic planes of surgery,with all the advantages of laparoscopic techniques,both in faster recovery and better immunological response. The importance of minimally invasive mesoresectional surgery is thus stressed and highlighted as the new frontier for a modern laparoscopic total right mesocolectomy.
文摘AIM To analyze the outcomes of living-donor liver transplantation(LDLT) using left-lobe(LL) or right-lobe(RL) small-for-size(SFS) grafts.METHODS Prospectively collected data of adult patients who underwent LDLT at our hospital in the period from January 2003 to December 2013 were reviewed. The patients were divided into the RL-LDLT group and the LL-LDLT group. The two groups were compared in terms of short-and long-term outcomes, including incidence of postoperative complication, graft function, graft survival, and patient survival. A SFS graft was defined as a graft with a ratio of graft weight(GW) to recipient standard liver volume(RSLV)(GW/RSLV) of < 50%. The Urata formula was used to estimate RSLV.RESULTS Totally 218 patients were included for analysis, with 199 patients in the RL-LDLT group and 19 patients in the LL-LDLT group. The two groups were similar in terms of age(median, 53 years in the RL-LDLT group and 52 years in the LL-LDLT group, P = 0.997) but had significantly different ratios of men to women(165:34 in the RL-LDLT group and 8:11 in the LL-LDLT group, P < 0.0001). The two groups were also significantly different in GW(P < 0.0001), GW/RSLV(P < 0.0001), and graft cold ischemic time(P = 0.007). When it comes to postoperative complication, the groups were comparable(P = 0.105). Five patients died in hospital,4(2%) in the RL-LDLT group and 1(5.3%) in the LLLDLT group(P = 0.918). There were 38 graft losses, 33(16.6%) in the RL-LDLT group and 5(26.3%) in the LL-LDLT group(P = 0.452). The 5-year graft survival rate was significantly better in the RL-LDLT group(95.2% vs 89.5%, P = 0.049). The two groups had similar 5-year patient survival rates(RL-LDLT: 86.8%, LL-LDLT: 89.5%, P = 0.476).CONCLUSION The use of SFS graft in LDLT requires careful tailormade surgical planning and meticulous operation. LLLDLT can be a good alternative to RL-LDLT with similar recipient outcomes but a lower donor risk. Further research into different patient conditions is needed in order to validate the use of LL graft.
文摘In this study, we investigated the changes in the right-to-left shunt (RLS) of the patent foramen ovale (PFO) at different phases of the Valsalva maneuver and analyzed the possible mechanisms. The study population consisted of 57 patients with symptoms highly suggestive of a PFO. These patients had been diagnosed with apsychia, migraine with aura, cerebral infarction, transient ischemic attack (TIA), and cerebral ischemia with unknown cause. Routine echocardiography was performed in all patients to rule out a cardiac malformation. Contrast-transcranial Doppler (c-TCD) and contrast-enhanced transthoracic echocardiography (c-TTE) were used to visualize and quantify the RLS. The standard apical four chamber view was used to observe the changes of E peak, A peak, and velocity-time integral (VTI) ratio of tricuspid blood flow during the strain phase and release phase of the Valsalva maneuver. Paired t-test was used to compare E peak, A peak, and VTI ratio of tricuspid blood flow during the different phases. The right-to-left shunt across the PFO (PFO-RLS) was graded in the two phases and compared by Kruskal-Wallis test. Compared with the strain phase of the Valsalva maneuver, the parameters of E, A, and VTI in diastolic period in patients with PFO-RLS at the release phase were significantly increased [54.30 ± 13.65 cm/s vs 100.35 ± 21.11 cm/s, 42.21 ± 12.32 cm/s vs 57.30 ± 18.88 cm/s, 10.34 ± 3.27 cm/s vs 19.58 ± 4.56 cm/s, respectively], and the difference was statistically significant. The positive consequence of PFO-RLS, as diagnosed by c-TTE with the Valsalva maneuver at the release phase of the Valsalva maneuver, was significantly higher than that at the strain phase of the Valsalva maneuver. At the beginning of release phase of the Valsalva maneuver, decreased intrathoracic pressure led to increased venous backflow into the right atrium. Thus, high-velocity blood flow rapidly pushed the PFO open, which resulted in a significant increase in the PFO-RLS. Therefore, the increase of the PFO-RLS during the Valsalva maneuver is caused by the impact of high-velocity blood flow the PFO.
文摘Background: The association of right coronary artery (RCA) stenosis in patients undergoing myocardial revascularization for left main coronary artery (LMCA) stenosis affects the prognosis. This study aimed to compare immediate results of patients with isolated LMCA stenosis and those with combined RCA stenosis. Patients and methods: We retrospectively evaluated 107 consecutive patients with LMCA disease who underwent coronary artery bypass grafts. The patients were divided into two groups: isolated LMCA stenosis (n = 36) and LMCA stenosis + RCA stenosis (n = 71). Different variables (preoperative, intra operative and post operative) were compared. Results: Patients with LMCA stenosis + RCA stenosis experienced higher prevalence of diabetes mellitus (p = 0.024) and smoker (p = 0.032). Also left ventricular EF was reduced (p = 0.004). Myocardial revascularization was more complete in patients with LMCA stenosis + RCA stenosis (p = 0.033), but in-hospital mortality rate was higher (12.6% vs 5.5%) in isolated LLMCA stenosis, but it did not reach statistical significance (p = 0.32). Except low output syndrome (LOS) that was frequent in presence of RCA stenosis (p = 0.026), no significant difference was found between groups for other complications. Conclusion: The presence of RCA stenosis in patients undergoing CABG for LMCA disease increases 30 day mortality but without significant impact on overall morbidities.
文摘Presented in this paper are 3 cases of hemorrhage of ascending aorta and left ventricle after open heart surgery treated by extracardial bypass in our hospital from Oct. 1994 to Dec. 1995. Remained aneurysmal wall enclosing conduit graft was used as a sac bypassed to right atrium to form a extracardial left-toright shunt in order to control bleeding and the results turned out to be satisfactory. The bypass and hemodynamically ignorable shunt can close spontaneously without complications with recovery of coagulation system. The technique may find wide application in clinical practice.
基金the Foundation for the Hospital La Paz Institute for Health Research,No.PI698Fundación Familia AlonsoFundación Antolín Garcíarena and the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowaska-Curie-’laCaixa’,No.713673。
文摘BACKGROUND Colorectal cancer(CRC)accounts for 9.4%of overall cancer deaths,ranking second after lung cancer.Despite the large number of factors tested to predict their outcome,most patients with similar variables show big differences in survival.Moreover,right-sided CRC(RCRC)and left-sided CRC(LCRC)patients exhibit large differences in outcome after surgical intervention as assessed by preoperative blood leukocyte status.We hypothesised that stronger indexes than circulating(blood)leukocyte ratios to predict RCRC and LCRC patient outcomes will result from combining both circulating and infiltrated(tumour/peritumour fixed tissues)concentrations of leukocytes.AIM To seek variables involving leukocyte balances in peripheral blood and tumour tissues and to predict the outcome of CRC patients.METHODS Sixty-five patients diagnosed with colon adenocarcinoma by the Digestive Surgery Service of the La Paz University Hospital(Madrid,Spain)were enrolled in this study:43 with RCRC and 22 with LCRC.Patients were followed-up from January 2017 to March 2021 to record overall survival(OS)and recurrence-free survival(RFS)after surgical interventions.Leukocyte concentrations in peripheral blood were determined by routine laboratory protocols.Paraffin-fixed samples of tumour and peritumoural tissues were assessed for leukocyte concentrations by immunohistochemical detection of CD4,CD8,and CD14 marker expression.Ratios of leukocyte concentration in blood and tissues were calculated and evaluated for their predictor values for OS and RFS with Spearman correlations and Cox univariate and multivariate proportional hazards regression,followed by the calculation of the receiver-operating characteristic and area under the curve(AUC)and the determination of Youden’s optimal cutoff values for those variables that significantly correlated with either RCRC or LCRC patient outcomes.RCRC patients from the cohort were randomly assigned to modelling and validation sets,and clinician-friendly nomograms were developed to predict OS and RFS from the respective significant indexes.The accuracy of the model was evaluated using calibration and validation plots.RESULTS The relationship of leukocyte ratios in blood and peritumour resulted in six robust predictors of worse OS in RCRC:CD8+lymphocyte content in peritumour(CD8pt,AUC=0.585,cutoff<8.250,P=0.0077);total lymphocyte content in peritumour(CD4CD8pt,AUC=0.550,cutoff<10.160,P=0.0188);lymphocyte-to-monocyte ratio in peritumour(LMRpt,AUC=0.807,cutoff<3.185,P=0.0028);CD8+LMR in peritumour(CD8MRpt,AUC=0.757,cutoff<1.650,P=0.0007);the ratio of blood LMR to LMR in peritumour(LMRb/LMRpt,AUC=0.672,cutoff>0.985,P=0.0244);and the ratio of blood LMR to CD8+LMR in peritumour(LMRb/CD8MRpt,AUC=0.601,cutoff>1.485,P=0.0101).In addition,three robust predictors of worse RFS in RCRC were found:LMRpt(AUC=0.737,cutoff<3.185,P=0.0046);LMRb/LMRpt(AUC=0.678,cutoff>0.985,P=0.0155)and LMRb/CD8MRpt(AUC=0.615,cutoff>1.485,P=0.0141).Furthermore,the ratio of blood LMR to CD4+LMR in peritumour(LMRb/CD4MRpt,AUC=0.786,cutoff>10.570,P=0.0416)was found to robustly predict poorer OS in LCRC patients.The nomograms showed moderate accuracy in predicting OS and RFS in RCRC patients,with concordance index of 0.600 and 0.605,respectively.CONCLUSION Easily obtainable variables at preoperative consultation,defining the status of leukocyte balances between peripheral blood and peritumoural tissues,are robust predictors for OS and RFS of both RCRC and LCRC patients.
文摘BACKGROUND Complete mesocolic excision(CME)with central vascular ligation(CVL)was proposed by Hohenberger in 2009.The CME principle has gradually become the technical standard for colon cancer surgery.How to achieve CME with CVL in laparoscopic right hemicolectomy(LRH)is controversial,and a unified standard approach is not yet available.In recent years,the authors’team has integrated the theory of membrane anatomy,tried to combine the cephalic approach with the classic medial approach(MA)for technical optimization,and proposed a cranialmedial mixed dominant approach(CMA).AIM To explore the feasibility of operational approaches for LRH with CME.METHODS In this retrospective cohort study,the clinical data of 57 patients with right-sided colon cancer(TNM stage I,II,or III)who underwent LRH with CME from January 2016 to June 2020 were collected and summarized.There were 31 patients in the traditional MA group and 26 in the CMA group.RESULTS There were no significant differences in baseline data between the two groups.The operation was shorter and the number of lymph nodes dissected was higher in the CMA group than in the MA group,but there was no significant difference in the number of positive lymph nodes,intraoperative blood loss,postoperative exhaust time,feeding time,postoperative hospital stay or postoperative complication incidence.CONCLUSION Our study shows that the CMA is a safe and feasible procedure for LRH with CME and has a unique advantage.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60977068,61178015 and 11102100)the Youth Foundation of Sanming University,China (Grant No. B201008/Q)
文摘Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the LHM,the intensity self-bending due to its propagation in the RHM can be compensated.In particular,if the propagation distance in the RHM is equal to that in the LHM and the refractive index of the LHM is n L =-1,the transverse intensity distribution of the Airy beam can return to its original state.
文摘Background: Transradial coronary angiography has established itself as safe alternative to transfemoral approach. Today, the artery of approach lies completely on the operator’s choice. The Right Radial Approach (RRA) has been a favorite for most of the interventional cardiologists due to the convenience in operating from the right side. The Left Radial Approach (LRA) has always been a neglected route. LRA does have many advantages over the right, the vascular anatomy being one of them. The aim of our study was to compare the right radial approach of diagnostic coronary angiography with left radial approach. Method: A total of 70 cases of Coronary Angiography (CAG) with normal Allen test and satisfying the inclusion criteria were prospectively observed and studied after randomly assigning them into two equal groups, LRA (Left Radial Approach) n = 35 and RRA (Right Radial Approach) n = 35. Multipurpose TIG (Tiger) catheter was used in both the approaches to catheterize the right as well as left coronary artery. Results: The access time, catheter manipulation time, procedure time, amount of contrast used, hospital stay, intensity of pain experienced, cost of the procedure and quality of coronary angiogram observed were statistically insignificant while the fluoroscopy time was slightly statistically significant which was independent to catheter manipulation time. Conclusions: The neglected Left Radial Approach to coronary angiography is as efficacious, safe and cost effective with reduction in arterial spasm complications when compared to the Right Radial Approach performed by multipurpose Tiger catheter.
基金Supported by the Scientific Research Foundation of Traditional Chinese Medicine of the Shanghai Health Bureau,No.2014LZ079Athe Scientific Research Plan Project of the Shanghai Science and Technology Committee,No.14401930800the Program of Shanghai Municipal Technology and Education Commission,No.16401970500
文摘AIM To explore the differences in the responses of left-sided colorectal cancer(LSCRC) and right-sided colon cancer(RSCC) to traditional Chinese medicine(TCM).METHODS Patients with postoperative stage I-III colorectal cancer(CRC) were enrolled and divided into the LSCRC with or without TCM and RSCC with or without TCM groups depending on the primary tumor side and TCM administration. Patients in the TCM group were given TCM for at least 6 mo. Our research adopted diseasefree survival(DFS) as the primary endpoint. We applied a Cox proportional hazards regression model for the multivariate factor analysis using Stata 12.0 and SPSS 22.0 software for data analysis.RESULTS Of the 817 patients included in our study, 617 had LSCRC(TCM group, n = 404; Non-TCM group, n = 213), and 200 had RSCC(TCM group, n = 132; NonTCM group, n = 68). The 6-year DFS for patients with LSCRC was 56.95% in the TCM group and 41.50% in the Non-TCM group(P = 0.000). For patients with RSCC, the 6-year DFS was 52.92% in the TCM group and 37.19% in the Non-TCM group(P = 0.003). Differences between LSCRC and RSCC were not statistically significant regardless of TCM ingestion.CONCLUSION Patients with either LSCRC or RSCC and who took TCM experienced longer DFS; furthermore, patients with RSCC benefited more from TCM in DFS.
文摘Currently, there are two rituals coexist in the world:"taking the left for the upper"and"taking the right for the up?per". The former is usually taken in domestic affairs such as meetings, dinners, etc. while the latter enjoys an overwhelmingly fa?vor in the west and so that it becomes the international practice in every conceivable social activities. The paper intends to offer a deep explanation of the differences of two rituals with adequate evidence and examples in some specific situations, say different kinds of seat arrangement in various large and small meetings, respectively in China and the west. Then it follows to provide the underlying reasons for the differences from the perspective of cultural difference. It finds that different denotation of"left"and"right"in English and Chinese may shed some light on the understanding of the two different rituals.
文摘A closed linear relation T in a Banach space X is called left(resp. right) Fredholm if it is upper(resp. lower) semi Fredholm and its range(resp. null space) is topologically complemented in X. We say that T is left(resp. right) Browder if it is left(resp. right)Fredholm and has a finite ascent(resp. descent). In this paper, we analyze the stability of the left(resp. right) Fredholm and the left(resp. right) Browder linear relations under commuting Riesz operator perturbations. Recent results of Zivkovic et al. to the case of bounded operators are covered.
基金supported by the National Natural Science Foundation of China (No. 51175442)the Fundamental Research Funds for the Central Universities (SWJTU12CX040)
文摘Levitation chassis, as an extremely important component of maglev vehicles, provides functions of transmitting levitation force and steering force, and directly affects the safety performance of the vehicle. Based on the vertical dynamics model of the levitation chassis, kinetic equations of the model are established, and a simulation program is designed to analyze the structural decoupling function of the chassis, especially under the influence of elastic constraints between the left and right modules, which are exclusively owned by maglev vehicles. A finite element model of the levitation chassis based on left-right decoupling is constructed. Analysis results of the model show that the mechanical properties of the chassis tailored for the vehicle meet the design requirements, and the stiffness and strength is adequate to bear the weight of the whole vehicle.
文摘We present a case of the right aortic arch with kommerell diverticulum (KD) and aberrant left subclavian artery in a symptomatic 50-year-old patient with a calcification in the presumed attachment site of the ligamentum arteriosum (LA) to the KD. In another 30-year-old male patient, the entire course of a calcified LA was demonstrated using multidetector row computed tomography.
