Autotomy of appendages is a self-protection mechanism in crustaceans,which is defined as the reflexive loss of a limb in response to predation,competition,or other environmental factors.Single-limb injuries were the m...Autotomy of appendages is a self-protection mechanism in crustaceans,which is defined as the reflexive loss of a limb in response to predation,competition,or other environmental factors.Single-limb injuries were the most common among the species surveyed in the present study,and the chelicerae were the most frequently lost appendages.After autotomy,hormones and signaling pathways are altered.Loss of limbs can affect foraging efficiency,although cheliped loss may be compensated by shifting to alternative prey or using both motor and oral appendages.In heterogeneous species,the loss of the major chelae may affect the selectivity of feeding.Autotomy can affect crustacean growth by reducing size increases at molting and altering the timing of ecdysis.In commercial production,removing chelicerae is an effective strategy to reduce cannibalism,and production of soft-shell crabs can be increased via autotomy.After autotomy,a new limb will regrow through regeneration and molting.This process involves the regulation of hormones,regrowth of nerves,and a number of signaling pathways that include the Wnt/β-catenin signaling pathway and transforming growth factorβsignaling pathway.Crustaceans are somewhat different from vertebrates in terms of regeneration.This review provides theoretical guidance about autotomy and regeneration applied in artificial aquaculture,and we offer several suggestions for future research on autotomy and regeneration in crustaceans.展开更多
This paper is mainly concerned with the coupling dynamic analysis of a complex spacecraft consisting of one main rigid platform, multiple liquid-filled cylindrical tanks, and a number of flexible appendages. Firstly, ...This paper is mainly concerned with the coupling dynamic analysis of a complex spacecraft consisting of one main rigid platform, multiple liquid-filled cylindrical tanks, and a number of flexible appendages. Firstly, the carrier potential function equations of liquid in the tanks are deduced according to the wall boundary conditions. Through employ- ing the Fourier-Bessel series expansion method, the dynamic boundaries conditions on a curved free-surface under a low-gravity environment are transformed to general simple differential equations and the rigid-liquid coupled sloshing dynamic state equations of liquid in tanks are obtained. The state vectors of rigid-liquid coupled equations are composed with the modal coordinates of the relative potential func- tion and the modal coordinates of wave height. Based on the B ernoulli-Euler beam theory and the D'Alembert's prin- ciple, the rigid-flexible coupled dynamic state equations of flexible appendages are directly derived, and the coordi- nate transform matrixes of maneuvering flexible appendages are precisely computed as time-varying. Then, the cou- pling dynamics state equations of the overall system of the spacecraft are modularly built by means of the Lagrange's equations in terms of quasi-coordinates. Lastly, the cou-piing dynamic performances of a typical complex spacecraft are studied. The availability and reliability of the presented method are also confirmed.展开更多
Nonlinear dynamics of liquid-filled rectangular tank with elastic appendages are studied. Based on the assumption of ideal fluid, the coupling dynamic equations of rigid tank, elastic appendages and liquid fuel are de...Nonlinear dynamics of liquid-filled rectangular tank with elastic appendages are studied. Based on the assumption of ideal fluid, the coupling dynamic equations of rigid tank, elastic appendages and liquid fuel are derived using H-O principle. In the case of pitch excitation, the modified potential function and wave height function are introduced to describe the moving boundary of fluid, then Galerkin's method is used to discretize the dynamic equations into ordinary differential equations. The natural frequencics of the coupling system are formulated in liquid depth, the length of the tank, etc. The formulae are confirmed by numerical simulations, which also show that the effects of liquid and elastic appendages on the attitude angular of rigid.展开更多
In this paper,we present an overview of numerical simulation methods for the flow around typical underwater vehicles at high Reynolds numbers,which highlights the dominant flow structures in different regions of inter...In this paper,we present an overview of numerical simulation methods for the flow around typical underwater vehicles at high Reynolds numbers,which highlights the dominant flow structures in different regions of interest.This overview covers the forebody,midbody,stern,wake region,and appendages and summarizes flow phenomena,including laminar-to-turbulent transition,turbulent boundary layers,flow under the influence of curvatures,wake interactions,and all associated complex vortex structures.Furthermore,the current issues and challenges of capturing these flow structures are addressed.This overview provides a deep insight into the use of numerical simulation methods,including the Reynolds-averaged Navier–Stokes(RANS)method,large eddy simulation(LES)method,and the hybrid RANS/LES method,and evaluates their applicability in capturing detailed flow features.展开更多
BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innova...BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some experience.CASE SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation.After the surgery,the occluder fell off and became free in the left ventricle,which is very dangerous.We innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage occluder.After the surgery,the patient recovered very well.CONCLUSION The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.展开更多
The use of anticoagulation therapy could prove to be controversial when trying to balance ischemic stroke and intracranial bleeding risks in patients with concurrent cerebral amyloid angiopathy(CAA)and atrial fibrilla...The use of anticoagulation therapy could prove to be controversial when trying to balance ischemic stroke and intracranial bleeding risks in patients with concurrent cerebral amyloid angiopathy(CAA)and atrial fibrillation(AF).In fact,CAA is an age-related cerebral vasculopathy that predisposes patients to intracerebral hemorrhage.Nevertheless,many AF patients require oral systemic dose-adjusted warfarin,direct oral anticoagulants(such as factor Xa inhibitors)or direct thrombin inhibitors to control often associated with cardioembolic stroke risk.The prevalence of both CAA and AF is expected to rise,due to the aging of the population.This clinical dilemma is becoming increasingly common.In patients with coexisting AF and CAA,the risks/benefits profile of anticoagulant therapy must be assessed for each patient individually due to the lack of a clear-cut consensus with regard to its risks in scientific literature.This review aims to provide an overview of the management of patients with concomitant AF and CAA and proposes the implementation of a risk-based decision-making algorithm.展开更多
Water beetles are proficient drag-powered swimmers, with oar-like legs. Inspired by this mechanism, here we propose a miniature robot, with mobility provided by a pair of legs with swimming appendages. The robot has o...Water beetles are proficient drag-powered swimmers, with oar-like legs. Inspired by this mechanism, here we propose a miniature robot, with mobility provided by a pair of legs with swimming appendages. The robot has optimized linkage structure to maximize the stroke angle, which is actuated by a single DC motor with a series of gears and a spring. A simplified swimming appendage model is proposed to calculate the deflection due to the applied drag force, and is compared with simulated data using COMSOL Multiphysies. Also, the swimming appendages are optimized by considering their locations on the legs using two fitness functions, and six different configurations are selected. We investigate the performance of the robot with various types of appendage using a high-speed camera, and motion capture cameras. The robot with the proposed configuration exhibits fast and efficient movement compared with other robots. In addition, the locomotion of the robot is analyzed by considering its dynamics, and compared with that of a water boatman (Corixidae).展开更多
Circular RNAs (circRNAs) are endogenous non-coding RNAs that participate in regulating gene expression in diverse biological and pathological processes. The roles of circRNAs in atrial fibrillation (AF) have not b...Circular RNAs (circRNAs) are endogenous non-coding RNAs that participate in regulating gene expression in diverse biological and pathological processes. The roles of circRNAs in atrial fibrillation (AF) have not been well elucidated. In the present study, circRNAs profile in the atrial appendages of patients with AF was examined. Methods Hematoxylin-eosin (HE) and Masson trichrome staining was performed on the atrial appendages of patients with sinus rhythm (SR) or AF, Expressions of fibrosis, rennin-angiotensin-aldo- sterone system (RAAS) and inflammation-associated genes were determined by quantitative reverse transcrip- tion PCR (qRT-PCR). CircRNAs expression profile in atrial appendages was detected by circ RNAs microarray. qRT-PCR was also used to determine the expression of 6 representative dys-regulated circRNAs. PCR products of concerned circRNAs were further identified by gel electrophoresis and DNA sequencing assay. Results Masson tricbrome staining result showed that fibrosis was increased in the atrial appendages of AF patients. The levels of collal, Col3al, fibrinectin-1 (FN1), 1L1-β and CRP mRNA expression were significantly up-regulated in the atrial appendages of AF patients. A circRNAs array revealed that circRNAs were dysregulated in the atrial appendages of AF patients, qRT-PCR results demonstrated that circRNA 100395 was up-regulated, circRNA_ 101270, circRNA_103820, circRNA_104168 and circRNA_100782 were down-regulated significantly in the atri- al appendages of AF patients compared to SR patients. Conclusions Fibrosis and inflammation occur in the atrial appendages of AF patients, which could relate tocircRNAs dysregulation.展开更多
Aims:Evidence is emerging that,in the setting of isomerism,the atrial and bronchial arrangement are not always concordant,nor are these patterns always harmonious with the arrangement of the abdominal organs.We aimed ...Aims:Evidence is emerging that,in the setting of isomerism,the atrial and bronchial arrangement are not always concordant,nor are these patterns always harmonious with the arrangement of the abdominal organs.We aimed to evaluate the concordance between these features in a cohort of patients with cardiac malformations in the setting of known isomerism,seeking to determine whether it was feasible to assess complexity on this basis,in this regard taking note of the potential value of bronchial as opposed to appendage morphology.Methods and Results:We studied 78 patients known to have isomerism of the bronchuses,43 with right and 35 with left isomerism.Appendage anatomy could be determined in 49 cases(63%),all but one of these being concordant with bronchial anatomy.When assessing abdominal features,in only 59 cases(76%)was splenic morphology in keeping with the thoracic findings.As expected,right isomerism was associated with greater complexity of cardiac malformations,with an odds ratio of 6.53,with confidence intervals from 2.2–19.3(p<0.001).The odds were slightly decreased with thoraco-abdominal disharmony,when lesions shown to carry higher risk were then found in the setting of left isomerism.Conclusion:Harmony is excellent between bronchial and appendage isomerism,but less so with the arrangement of the abdominal organs.Right isomerism in our cohort,was indicative of a sixfold increase in intracardiac complexity.When discordance was found between the systems,however,the cardiac anomalies were less typical of the anticipated findings for right vs.left isomerism of the appendages.展开更多
For patients with atrial fibrillation with an increased risk of stroke and contraindications to long-term anticoagulation,percutaneous left atrial appendage closure(LAAC)has become an important alternative to long-ter...For patients with atrial fibrillation with an increased risk of stroke and contraindications to long-term anticoagulation,percutaneous left atrial appendage closure(LAAC)has become an important alternative to long-term oral anticoagulation.Incomplete closure of the LAAC during the procedure leads to faster blood flow in the interstitial space around the device,resulting in peri-device leak(PDL),which is not uncommon.Studies are still inconclusive in determining the incidence,long-term safety,and management of PDL.Therefore,this article reviewed the progress made in the research and treatment of PDL after LAAC.展开更多
A rare differential diagnosis for severe abdominal pain is acute epiploic appendagitis. Its symptoms resemble those of acute diverticulitis, acute appendicitis, or omental infarction quite a bit. The primary imaging m...A rare differential diagnosis for severe abdominal pain is acute epiploic appendagitis. Its symptoms resemble those of acute diverticulitis, acute appendicitis, or omental infarction quite a bit. The primary imaging method used for diagnosis is computed tomography (CT). We are describing the case of a 27-year-old guy who underwent an abdominal ultrasonography after complaining of severe left lower quadrant abdominal pain. It identified an oval and non-compressible hyperechoic mass in the left iliac fossa. The mass was surrounded by a hypoechoic rim and there was no color Doppler signal. In the absence of CT, radiologists must be able to diagnose acute epiploic appendagitis on ultrasound in order to avoid unnecessary hospital admission, pricey laboratory tests, antibiotic treatment, and unnecessary surgery. In this instance, the patient was spared from ionization exposure from a potential CT scan and other invasive treatments including surgery with associated costs because of the reliable ultrasound diagnosis of epiploic appendagitis. After receiving conservative medical treatment, the patient was placed under surveillance and then discharged.展开更多
In marine engineering,appendages such as fin stabilizers and/or T-foils are made to rotate and to reduce the motion of ships.Research on the hydrodynamics of ships fitted with active appendages has significantly impro...In marine engineering,appendages such as fin stabilizers and/or T-foils are made to rotate and to reduce the motion of ships.Research on the hydrodynamics of ships fitted with active appendages has significantly improved the design and control of such ships.However,most studies focus on fixed rather than rotating appendages,thereby ignoring the hydrodynamic unsteadiness of active appendages.To enhance the reliability and precision of the numerical simulations,we propose the use of overlapping grids for simulating advanced catamarans fitted with a pair of rotating T-foils under each bow.The fundamental purpose of the overlapping grid technique is to realize information exchange via regional overlap sharing in each subdomain of the computing domain,instead of using the method of boundary sharing,thus greatly alleviating the difficulty of generating the subdomain grid;moreover,the technique guarantees the quality of the subdomain grid.Within the main computational domain,a subdomain was allocated to accommodate the T-foil.Overlapping meshes near the interface between the two domains enable information flow during the simulation;the overlapping grids are updated at every iteration step because the subdomain rotates.The instantaneous trim and sinkage responses of the catamaran to the T-foil rotation were reproduced.From the moment the active T-foil stopped moving,there was no change in the ship’s sailing attitude,indicating that the response was in real time.By comparing with EFD data,the numerical results showed reasonable agreement,indicating the feasibility and effectiveness of the technique in simulating the hydrodynamics of ships fitted with active appendages.展开更多
In the last issue,two case reports separately present examples of the extremely rare and complex congenital heart diseases that show concordant atrioventricular connections to the L-looped ventricles in the presence o...In the last issue,two case reports separately present examples of the extremely rare and complex congenital heart diseases that show concordant atrioventricular connections to the L-looped ventricles in the presence of situs solitus.Both cases highlight that the relationship between the two ventricles within the ventricular mass is not always harmonious with the given atrioventricular connection.Such disharmony between the connections and relationships requires careful assessment of the three basic facets of cardiac building blocks,namely their morphology,the relationship of their component parts,and their connections with the adjacent segments.3D imaging and printing can now facilitate an otherwise difficult diagnosis in such complex situations.Rotation of either the 3D images or the models permit accurate assessment of the ventricular topologic pattern by creating the right ventricular en-face septal view,thus facilitating placement of the observer’s hands.As we now emphasize,an alternative approach,which might prove more attractive to imagers,is to rotate the ventricular mass to provide the ventricular apical view,thus permitting determination of the ventricular relationship without using the hands.展开更多
A maternally inherited 828 kb microdeletion of 2q37.3 manifested in a 3-week-old premature boy as left juxtaposition of the atrial appendages associated with tricuspid atresia,double outlet infundibulum,subvalvar pulm...A maternally inherited 828 kb microdeletion of 2q37.3 manifested in a 3-week-old premature boy as left juxtaposition of the atrial appendages associated with tricuspid atresia,double outlet infundibulum,subvalvar pulmonary atresia,large secundum atrial septal defect,and right aortic arch with mirror-image branching,consistent with developmental arrest early in heart looping.To the best of our knowledge,no previous 2q37 deletion syndrome has been reported with such a severe cardiac dysmorphology.Hence,this case adds to the cardiac phenotypes identified in 2q37 deletion syndrome.展开更多
Comparative morphological study of five varieties of Colocasia esculenta (L.) Schott present in Anambra State, Nigeria was carried out, in order to furnish plant taxonomists with information which could be of great he...Comparative morphological study of five varieties of Colocasia esculenta (L.) Schott present in Anambra State, Nigeria was carried out, in order to furnish plant taxonomists with information which could be of great help in delimitation of the varieties. Significant difference was established at p < 0.05. The result showed that adaxial surface of “kochuo” had a purplish dot on the centre, abaxial leaf surface had a conspicuous purplish colour at the point of attachment to the leaf, and the cormels had numerous striking vertical purple stripes on the surface. There was presence of foliaceous (leaf-like) appendages at the veins of the abaxial surface of the leaf of “ogeriobosi”. The leaf length ranged from 35.6 ± 7.70 cm (“kochuo”) to 49.9 ± 3.55 cm (“ogeriobosi”). Petiole length of “ogeriobosi” was the highest (63.3 ± 3.83 cm), whereas the least was Colocasia esculenta var. antiquorum (26.67 ± 2.20 cm). The corm length ranged from 4.10 ± 0.10 cm (Colocasia esculenta var. antiquorum) to 8.60 ± 0.35 cm (“ogeriobosi”), while the cormel length ranged from 3.70 ± 0.96 cm (Colocasia esculenta var. antiquorum) to 7.03 ± 0.36 cm (“ogeriobosi”). This work has revealed diagnostic and differential morphological characters, which could be useful for identification and description of varieties of C. esculenta. In addition, it provided additional information which might be helpful in resolving the on-going controversy in the taxonomy of Colocasia, which would, in turn, probably lead to possible delimitation of C. esculenta.展开更多
The present article report a rare case of intraosseous dermoid cyst in mandible which clinically and radio-graphicaly presented as mandibular cyst. The diagnosis of dermoid cyst was confirmed histologically. A 20 year...The present article report a rare case of intraosseous dermoid cyst in mandible which clinically and radio-graphicaly presented as mandibular cyst. The diagnosis of dermoid cyst was confirmed histologically. A 20 year old patient was admitted to our Department with the complaint of swelling in left lower jaw with occasional pain. Radiographic examination revealed a radiolucent lesion extending from left 2nd molar to right premolar region. On surgical exploration the lesion was cystic in nature full of hair and keratinized tissues. The tissue was sent for the histopathological examination and macroscopic feature reveal numerous bits of soft tissue. The tissues were creamish brown in color, firm in consistency, with largest tissue measuring 2.5 × 1.5 × 0.5 cm in dimension. Few hair follicles were also evident within it. The histopathology reveal cyst lined by stratified squamous hyperor- thokeratinized epithelium supported by a fibrous connective tissue wall. The cystic epithelium is showing melanin pigmentation in the basal cell layer. Ab-undant onion skin keratin is seen within the cyst lumen. The epithelial lining as well as cyst wall shows numerous skin appendages such as lobules of seba-ceous glands. The underlying connective tissue shows mild chronic inflammatory infiltrate mainly composed of lymphocytes.展开更多
The herbal medicine occupy distinct position right from ancient period. The plant Calotorpis procera is known by different name in different part of world like French cotton, Alarka, or Madar, Rooster tree, and Widuri...The herbal medicine occupy distinct position right from ancient period. The plant Calotorpis procera is known by different name in different part of world like French cotton, Alarka, or Madar, Rooster tree, and Widuri. The plant is poisonous can lead to blindness if its juice is put in to the eyes. The same plant is used for Ayurvedic medicines. The medicinal properties like Calotropin isolated from latex is used as remedy for painful tooth cavities rheumatism, sy-philis, leprosy and edema, for ring worm, syphilitic soreness, and leprosy cutanous dryness and toothache. Latex is al so used in the treatment of gum bleeding and as odontagic. Flowers can all so be used for too-thache, and ringworm infection. As the adage goes excess leads to distress, the judicious use of herbal medication is recommended otherwise it will lead to complication, as described in the case report.展开更多
In order to establish the evolutionary relationships and resolve the polyphyletic nature of Dothideomycetes,we are studying their natural classification based on both morphology and multigene phylogeny.In this paper w...In order to establish the evolutionary relationships and resolve the polyphyletic nature of Dothideomycetes,we are studying their natural classification based on both morphology and multigene phylogeny.In this paper we introduce Vaginatispora appendiculata,a novel species on dead twigs from southern Thailand.Morphological character differences and analyses of combined LSU,TEF,SSU and ITS sequence datasets support the validity of the new species and its placement in Vaginatispora(Lophiostomataceae).展开更多
Atrial fibrillation (AF) is the most common cardiac ar-rhythmia in clinical practice with an increasing incidenceand prevalence. With ageing, the risk of thromboembolicand hemorrhagic events increases dramatically. ...Atrial fibrillation (AF) is the most common cardiac ar-rhythmia in clinical practice with an increasing incidenceand prevalence. With ageing, the risk of thromboembolicand hemorrhagic events increases dramatically. As it hasbeen reported previously, 3-year survival rate among pa-tients with AF over 75 years of age after stroke is less than50%, and almost 90% of those patients will remain dis-abled.展开更多
Attitude maneuver of liquid-filled spacecraft with an appendage as a cantilever beam by momentum wheel is studied. The dynamic equations are derived by conserva- tion of angular momentum and force equilibrium principl...Attitude maneuver of liquid-filled spacecraft with an appendage as a cantilever beam by momentum wheel is studied. The dynamic equations are derived by conserva- tion of angular momentum and force equilibrium principle. A feedback control strategy of the momentum wheel is ap- plied for the attitude maneuver. The residual nutation of the spacecraft in maneuver process changes with some chosen parameters, such as steady state time, locations of the liq- uid container and the appendage, and appendage parame- ters. The results indicate that locations in the second and fourth quadrants of the body-fixed coordinate system and the second quadrant of the wall of the main body are better choices for.placing the liquid containers and the appendage than other locations if they can be placed randomly. Higher density and thicker cross section are better for lowering the residual nutation if they can be changed. Light appendage can be modeled as a rigid body, which results in a larger residual nutation than a flexible model though. The resid- ual nutation decreases with increasing absolute value of the initial sloshing angular height.展开更多
基金funded by the National Natural Science Foundation of China(Nos.32172993,42106104)the Ningbo Provincial Natural Science Foundation of China(No.202003N4181).
文摘Autotomy of appendages is a self-protection mechanism in crustaceans,which is defined as the reflexive loss of a limb in response to predation,competition,or other environmental factors.Single-limb injuries were the most common among the species surveyed in the present study,and the chelicerae were the most frequently lost appendages.After autotomy,hormones and signaling pathways are altered.Loss of limbs can affect foraging efficiency,although cheliped loss may be compensated by shifting to alternative prey or using both motor and oral appendages.In heterogeneous species,the loss of the major chelae may affect the selectivity of feeding.Autotomy can affect crustacean growth by reducing size increases at molting and altering the timing of ecdysis.In commercial production,removing chelicerae is an effective strategy to reduce cannibalism,and production of soft-shell crabs can be increased via autotomy.After autotomy,a new limb will regrow through regeneration and molting.This process involves the regulation of hormones,regrowth of nerves,and a number of signaling pathways that include the Wnt/β-catenin signaling pathway and transforming growth factorβsignaling pathway.Crustaceans are somewhat different from vertebrates in terms of regeneration.This review provides theoretical guidance about autotomy and regeneration applied in artificial aquaculture,and we offer several suggestions for future research on autotomy and regeneration in crustaceans.
基金project was supported by the National Natural Science Foundation of China (Grants 11472041, 11302244, 11532002)Guangxi Natural Science Foundation (2015GXNSFBA 139013)
文摘This paper is mainly concerned with the coupling dynamic analysis of a complex spacecraft consisting of one main rigid platform, multiple liquid-filled cylindrical tanks, and a number of flexible appendages. Firstly, the carrier potential function equations of liquid in the tanks are deduced according to the wall boundary conditions. Through employ- ing the Fourier-Bessel series expansion method, the dynamic boundaries conditions on a curved free-surface under a low-gravity environment are transformed to general simple differential equations and the rigid-liquid coupled sloshing dynamic state equations of liquid in tanks are obtained. The state vectors of rigid-liquid coupled equations are composed with the modal coordinates of the relative potential func- tion and the modal coordinates of wave height. Based on the B ernoulli-Euler beam theory and the D'Alembert's prin- ciple, the rigid-flexible coupled dynamic state equations of flexible appendages are directly derived, and the coordi- nate transform matrixes of maneuvering flexible appendages are precisely computed as time-varying. Then, the cou- pling dynamics state equations of the overall system of the spacecraft are modularly built by means of the Lagrange's equations in terms of quasi-coordinates. Lastly, the cou-piing dynamic performances of a typical complex spacecraft are studied. The availability and reliability of the presented method are also confirmed.
基金Project supported by the National Natural Science Foundation of China (Nos. 10302013 and 10572022)
文摘Nonlinear dynamics of liquid-filled rectangular tank with elastic appendages are studied. Based on the assumption of ideal fluid, the coupling dynamic equations of rigid tank, elastic appendages and liquid fuel are derived using H-O principle. In the case of pitch excitation, the modified potential function and wave height function are introduced to describe the moving boundary of fluid, then Galerkin's method is used to discretize the dynamic equations into ordinary differential equations. The natural frequencics of the coupling system are formulated in liquid depth, the length of the tank, etc. The formulae are confirmed by numerical simulations, which also show that the effects of liquid and elastic appendages on the attitude angular of rigid.
基金Supported by the National Natural Science Foundation of China under Grant No.52131102.
文摘In this paper,we present an overview of numerical simulation methods for the flow around typical underwater vehicles at high Reynolds numbers,which highlights the dominant flow structures in different regions of interest.This overview covers the forebody,midbody,stern,wake region,and appendages and summarizes flow phenomena,including laminar-to-turbulent transition,turbulent boundary layers,flow under the influence of curvatures,wake interactions,and all associated complex vortex structures.Furthermore,the current issues and challenges of capturing these flow structures are addressed.This overview provides a deep insight into the use of numerical simulation methods,including the Reynolds-averaged Navier–Stokes(RANS)method,large eddy simulation(LES)method,and the hybrid RANS/LES method,and evaluates their applicability in capturing detailed flow features.
文摘BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some experience.CASE SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation.After the surgery,the occluder fell off and became free in the left ventricle,which is very dangerous.We innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage occluder.After the surgery,the patient recovered very well.CONCLUSION The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.
文摘The use of anticoagulation therapy could prove to be controversial when trying to balance ischemic stroke and intracranial bleeding risks in patients with concurrent cerebral amyloid angiopathy(CAA)and atrial fibrillation(AF).In fact,CAA is an age-related cerebral vasculopathy that predisposes patients to intracerebral hemorrhage.Nevertheless,many AF patients require oral systemic dose-adjusted warfarin,direct oral anticoagulants(such as factor Xa inhibitors)or direct thrombin inhibitors to control often associated with cardioembolic stroke risk.The prevalence of both CAA and AF is expected to rise,due to the aging of the population.This clinical dilemma is becoming increasingly common.In patients with coexisting AF and CAA,the risks/benefits profile of anticoagulant therapy must be assessed for each patient individually due to the lack of a clear-cut consensus with regard to its risks in scientific literature.This review aims to provide an overview of the management of patients with concomitant AF and CAA and proposes the implementation of a risk-based decision-making algorithm.
文摘Water beetles are proficient drag-powered swimmers, with oar-like legs. Inspired by this mechanism, here we propose a miniature robot, with mobility provided by a pair of legs with swimming appendages. The robot has optimized linkage structure to maximize the stroke angle, which is actuated by a single DC motor with a series of gears and a spring. A simplified swimming appendage model is proposed to calculate the deflection due to the applied drag force, and is compared with simulated data using COMSOL Multiphysies. Also, the swimming appendages are optimized by considering their locations on the legs using two fitness functions, and six different configurations are selected. We investigate the performance of the robot with various types of appendage using a high-speed camera, and motion capture cameras. The robot with the proposed configuration exhibits fast and efficient movement compared with other robots. In addition, the locomotion of the robot is analyzed by considering its dynamics, and compared with that of a water boatman (Corixidae).
基金supported by grants from the National Natural Science Foundation of China(No.81470439/81270222/81302779/81370295)Natural Science Foundation of Guangdong Province(No.2014A030313635/S2011020005911)
文摘Circular RNAs (circRNAs) are endogenous non-coding RNAs that participate in regulating gene expression in diverse biological and pathological processes. The roles of circRNAs in atrial fibrillation (AF) have not been well elucidated. In the present study, circRNAs profile in the atrial appendages of patients with AF was examined. Methods Hematoxylin-eosin (HE) and Masson trichrome staining was performed on the atrial appendages of patients with sinus rhythm (SR) or AF, Expressions of fibrosis, rennin-angiotensin-aldo- sterone system (RAAS) and inflammation-associated genes were determined by quantitative reverse transcrip- tion PCR (qRT-PCR). CircRNAs expression profile in atrial appendages was detected by circ RNAs microarray. qRT-PCR was also used to determine the expression of 6 representative dys-regulated circRNAs. PCR products of concerned circRNAs were further identified by gel electrophoresis and DNA sequencing assay. Results Masson tricbrome staining result showed that fibrosis was increased in the atrial appendages of AF patients. The levels of collal, Col3al, fibrinectin-1 (FN1), 1L1-β and CRP mRNA expression were significantly up-regulated in the atrial appendages of AF patients. A circRNAs array revealed that circRNAs were dysregulated in the atrial appendages of AF patients, qRT-PCR results demonstrated that circRNA 100395 was up-regulated, circRNA_ 101270, circRNA_103820, circRNA_104168 and circRNA_100782 were down-regulated significantly in the atri- al appendages of AF patients compared to SR patients. Conclusions Fibrosis and inflammation occur in the atrial appendages of AF patients, which could relate tocircRNAs dysregulation.
文摘Aims:Evidence is emerging that,in the setting of isomerism,the atrial and bronchial arrangement are not always concordant,nor are these patterns always harmonious with the arrangement of the abdominal organs.We aimed to evaluate the concordance between these features in a cohort of patients with cardiac malformations in the setting of known isomerism,seeking to determine whether it was feasible to assess complexity on this basis,in this regard taking note of the potential value of bronchial as opposed to appendage morphology.Methods and Results:We studied 78 patients known to have isomerism of the bronchuses,43 with right and 35 with left isomerism.Appendage anatomy could be determined in 49 cases(63%),all but one of these being concordant with bronchial anatomy.When assessing abdominal features,in only 59 cases(76%)was splenic morphology in keeping with the thoracic findings.As expected,right isomerism was associated with greater complexity of cardiac malformations,with an odds ratio of 6.53,with confidence intervals from 2.2–19.3(p<0.001).The odds were slightly decreased with thoraco-abdominal disharmony,when lesions shown to carry higher risk were then found in the setting of left isomerism.Conclusion:Harmony is excellent between bronchial and appendage isomerism,but less so with the arrangement of the abdominal organs.Right isomerism in our cohort,was indicative of a sixfold increase in intracardiac complexity.When discordance was found between the systems,however,the cardiac anomalies were less typical of the anticipated findings for right vs.left isomerism of the appendages.
基金Supported by Zhejiang Provincial Foundation for Medical and Health Sciences,No.2021KY980.
文摘For patients with atrial fibrillation with an increased risk of stroke and contraindications to long-term anticoagulation,percutaneous left atrial appendage closure(LAAC)has become an important alternative to long-term oral anticoagulation.Incomplete closure of the LAAC during the procedure leads to faster blood flow in the interstitial space around the device,resulting in peri-device leak(PDL),which is not uncommon.Studies are still inconclusive in determining the incidence,long-term safety,and management of PDL.Therefore,this article reviewed the progress made in the research and treatment of PDL after LAAC.
文摘A rare differential diagnosis for severe abdominal pain is acute epiploic appendagitis. Its symptoms resemble those of acute diverticulitis, acute appendicitis, or omental infarction quite a bit. The primary imaging method used for diagnosis is computed tomography (CT). We are describing the case of a 27-year-old guy who underwent an abdominal ultrasonography after complaining of severe left lower quadrant abdominal pain. It identified an oval and non-compressible hyperechoic mass in the left iliac fossa. The mass was surrounded by a hypoechoic rim and there was no color Doppler signal. In the absence of CT, radiologists must be able to diagnose acute epiploic appendagitis on ultrasound in order to avoid unnecessary hospital admission, pricey laboratory tests, antibiotic treatment, and unnecessary surgery. In this instance, the patient was spared from ionization exposure from a potential CT scan and other invasive treatments including surgery with associated costs because of the reliable ultrasound diagnosis of epiploic appendagitis. After receiving conservative medical treatment, the patient was placed under surveillance and then discharged.
基金Supported by the National Natural Science Foundation of China(Grant No.51509053)
文摘In marine engineering,appendages such as fin stabilizers and/or T-foils are made to rotate and to reduce the motion of ships.Research on the hydrodynamics of ships fitted with active appendages has significantly improved the design and control of such ships.However,most studies focus on fixed rather than rotating appendages,thereby ignoring the hydrodynamic unsteadiness of active appendages.To enhance the reliability and precision of the numerical simulations,we propose the use of overlapping grids for simulating advanced catamarans fitted with a pair of rotating T-foils under each bow.The fundamental purpose of the overlapping grid technique is to realize information exchange via regional overlap sharing in each subdomain of the computing domain,instead of using the method of boundary sharing,thus greatly alleviating the difficulty of generating the subdomain grid;moreover,the technique guarantees the quality of the subdomain grid.Within the main computational domain,a subdomain was allocated to accommodate the T-foil.Overlapping meshes near the interface between the two domains enable information flow during the simulation;the overlapping grids are updated at every iteration step because the subdomain rotates.The instantaneous trim and sinkage responses of the catamaran to the T-foil rotation were reproduced.From the moment the active T-foil stopped moving,there was no change in the ship’s sailing attitude,indicating that the response was in real time.By comparing with EFD data,the numerical results showed reasonable agreement,indicating the feasibility and effectiveness of the technique in simulating the hydrodynamics of ships fitted with active appendages.
文摘In the last issue,two case reports separately present examples of the extremely rare and complex congenital heart diseases that show concordant atrioventricular connections to the L-looped ventricles in the presence of situs solitus.Both cases highlight that the relationship between the two ventricles within the ventricular mass is not always harmonious with the given atrioventricular connection.Such disharmony between the connections and relationships requires careful assessment of the three basic facets of cardiac building blocks,namely their morphology,the relationship of their component parts,and their connections with the adjacent segments.3D imaging and printing can now facilitate an otherwise difficult diagnosis in such complex situations.Rotation of either the 3D images or the models permit accurate assessment of the ventricular topologic pattern by creating the right ventricular en-face septal view,thus facilitating placement of the observer’s hands.As we now emphasize,an alternative approach,which might prove more attractive to imagers,is to rotate the ventricular mass to provide the ventricular apical view,thus permitting determination of the ventricular relationship without using the hands.
文摘A maternally inherited 828 kb microdeletion of 2q37.3 manifested in a 3-week-old premature boy as left juxtaposition of the atrial appendages associated with tricuspid atresia,double outlet infundibulum,subvalvar pulmonary atresia,large secundum atrial septal defect,and right aortic arch with mirror-image branching,consistent with developmental arrest early in heart looping.To the best of our knowledge,no previous 2q37 deletion syndrome has been reported with such a severe cardiac dysmorphology.Hence,this case adds to the cardiac phenotypes identified in 2q37 deletion syndrome.
文摘Comparative morphological study of five varieties of Colocasia esculenta (L.) Schott present in Anambra State, Nigeria was carried out, in order to furnish plant taxonomists with information which could be of great help in delimitation of the varieties. Significant difference was established at p < 0.05. The result showed that adaxial surface of “kochuo” had a purplish dot on the centre, abaxial leaf surface had a conspicuous purplish colour at the point of attachment to the leaf, and the cormels had numerous striking vertical purple stripes on the surface. There was presence of foliaceous (leaf-like) appendages at the veins of the abaxial surface of the leaf of “ogeriobosi”. The leaf length ranged from 35.6 ± 7.70 cm (“kochuo”) to 49.9 ± 3.55 cm (“ogeriobosi”). Petiole length of “ogeriobosi” was the highest (63.3 ± 3.83 cm), whereas the least was Colocasia esculenta var. antiquorum (26.67 ± 2.20 cm). The corm length ranged from 4.10 ± 0.10 cm (Colocasia esculenta var. antiquorum) to 8.60 ± 0.35 cm (“ogeriobosi”), while the cormel length ranged from 3.70 ± 0.96 cm (Colocasia esculenta var. antiquorum) to 7.03 ± 0.36 cm (“ogeriobosi”). This work has revealed diagnostic and differential morphological characters, which could be useful for identification and description of varieties of C. esculenta. In addition, it provided additional information which might be helpful in resolving the on-going controversy in the taxonomy of Colocasia, which would, in turn, probably lead to possible delimitation of C. esculenta.
文摘The present article report a rare case of intraosseous dermoid cyst in mandible which clinically and radio-graphicaly presented as mandibular cyst. The diagnosis of dermoid cyst was confirmed histologically. A 20 year old patient was admitted to our Department with the complaint of swelling in left lower jaw with occasional pain. Radiographic examination revealed a radiolucent lesion extending from left 2nd molar to right premolar region. On surgical exploration the lesion was cystic in nature full of hair and keratinized tissues. The tissue was sent for the histopathological examination and macroscopic feature reveal numerous bits of soft tissue. The tissues were creamish brown in color, firm in consistency, with largest tissue measuring 2.5 × 1.5 × 0.5 cm in dimension. Few hair follicles were also evident within it. The histopathology reveal cyst lined by stratified squamous hyperor- thokeratinized epithelium supported by a fibrous connective tissue wall. The cystic epithelium is showing melanin pigmentation in the basal cell layer. Ab-undant onion skin keratin is seen within the cyst lumen. The epithelial lining as well as cyst wall shows numerous skin appendages such as lobules of seba-ceous glands. The underlying connective tissue shows mild chronic inflammatory infiltrate mainly composed of lymphocytes.
文摘The herbal medicine occupy distinct position right from ancient period. The plant Calotorpis procera is known by different name in different part of world like French cotton, Alarka, or Madar, Rooster tree, and Widuri. The plant is poisonous can lead to blindness if its juice is put in to the eyes. The same plant is used for Ayurvedic medicines. The medicinal properties like Calotropin isolated from latex is used as remedy for painful tooth cavities rheumatism, sy-philis, leprosy and edema, for ring worm, syphilitic soreness, and leprosy cutanous dryness and toothache. Latex is al so used in the treatment of gum bleeding and as odontagic. Flowers can all so be used for too-thache, and ringworm infection. As the adage goes excess leads to distress, the judicious use of herbal medication is recommended otherwise it will lead to complication, as described in the case report.
基金supported by the International Research Group Program(IRG-14-27)。
文摘In order to establish the evolutionary relationships and resolve the polyphyletic nature of Dothideomycetes,we are studying their natural classification based on both morphology and multigene phylogeny.In this paper we introduce Vaginatispora appendiculata,a novel species on dead twigs from southern Thailand.Morphological character differences and analyses of combined LSU,TEF,SSU and ITS sequence datasets support the validity of the new species and its placement in Vaginatispora(Lophiostomataceae).
文摘Atrial fibrillation (AF) is the most common cardiac ar-rhythmia in clinical practice with an increasing incidenceand prevalence. With ageing, the risk of thromboembolicand hemorrhagic events increases dramatically. As it hasbeen reported previously, 3-year survival rate among pa-tients with AF over 75 years of age after stroke is less than50%, and almost 90% of those patients will remain dis-abled.
基金supported by the National Natural Science Foundation of China (11072030)
文摘Attitude maneuver of liquid-filled spacecraft with an appendage as a cantilever beam by momentum wheel is studied. The dynamic equations are derived by conserva- tion of angular momentum and force equilibrium principle. A feedback control strategy of the momentum wheel is ap- plied for the attitude maneuver. The residual nutation of the spacecraft in maneuver process changes with some chosen parameters, such as steady state time, locations of the liq- uid container and the appendage, and appendage parame- ters. The results indicate that locations in the second and fourth quadrants of the body-fixed coordinate system and the second quadrant of the wall of the main body are better choices for.placing the liquid containers and the appendage than other locations if they can be placed randomly. Higher density and thicker cross section are better for lowering the residual nutation if they can be changed. Light appendage can be modeled as a rigid body, which results in a larger residual nutation than a flexible model though. The resid- ual nutation decreases with increasing absolute value of the initial sloshing angular height.