Wire Frame Research Articles

Topological Analysis for Arteriovenous Malformations via Computed Tomography Angiography: Part 2: Practical Application.

Background:In a previous study, the authors outlined a technique for calculating the number of abnormal vascular loop structures described in 3-dimensional computed tomography angiography. To be developed into a quantitative evaluation method for soft-tissue arteriovenous malformations (AVMs), the concept needs assessment of validity.Methods:Computed tomography angiography results of 19 soft-tissue AVMs and 18 control abdominal vessels are utilized. Enhanced vascular lumen regions over 120 HU were extracted by a region growing method and skeletonized into wire frame graph models. The number of vascular loop structures in graphs is calculated as 1 − [Number of nodes] + [Number of edges], and results are compared between AVM/control groups, pre-/postprogression, and pre-/posttreatment.Results:Average vascular lumen capacity of AVMs was 57.5 ml/lesion, and average number of vascular loops was 548 loops/lesion. Loop density of AVMs (weighted average, 9.5 loops/ml) exhibited statistically significant (P < 0.001) greater value than normal abdominal blood vessels (weighted average, 1.3 loops/ml). In all 4 cases without treatment, number of loops and loop density both increased. Particularly, number of loops increased greatly by 2 times or more in 3 cases. In all 7 cases with treatment, number of loops and vascular lumen capacity significantly (P = 0.0156) decreased. Particularly, number of loops showed clearer decrease in cases with entire lesion treatment than partial treatment.Conclusions:Total number of described vascular loop structures and their density or volume well reflected the existence, progression, and remission of soft-tissue AVMs. Topological analysis can be expected to be developed into a quantitative evaluation for AVMs.

Results of the U.S. Food and Drug Administration Continued Access Clinical Trial of the GORE HELEX Septal Occluder for Secundum Atrial Septal Defect

ObjectivesThis report describes the immediate, 1-, and 5-year follow-up results of the U.S. Food and Drug Administration Continued Access clinical trial of the GORE HELEX Septal Occluder (W. L. Gore & Associates, Inc., Flagstaff, Arizona) for closure of secundum atrial septal defect. BackgroundThe trial was conducted between May 2003 and August 2006 to allow continued enrollment in a trial of the investigational device during review of data from the Pivotal Trial. Devices with hydrophilic coating on the expanded polytetrafluoroethylene to improve echocardiographic visualization were first used in this trial. MethodsA total of 137 devices were implanted in 137 patients at 13 US institutions. Evaluations were scheduled at 1, 6, and 12 months for the initial trial and at 36 and 60 months for a later extension of the trial in those who consented to longer term evaluations. ResultsTwelve-month follow-up was completed on 122 of 126 patients with implantations, and 5-year follow-up on 83 of 95 patients who agreed to the trial extension. The overall clinical success rate was 96.7%, and the major adverse event rate 3.6%. Wire frame fractures were seen in 11.7% of patients with no clinical symptoms. A trivial, clinically insignificant leak was seen, or could not be ruled out, in 26.6% of patients at the 5-year evaluation, but no clinically significant leaks were seen. No patient experienced an erosion or sudden catastrophic event. ConclusionsThe immediate, 1-, and 5-year follow-up outcomes of the Continued Access clinical trial continue to demonstrate that the GORE HELEX Septal Occluder is a safe and effective transcatheter occluder for repair of ostium secundum atrial septal defect.

Progress in developing a living human tissue-engineered tri-leaflet heart valve assembled from tissue produced by the self-assembly approach

The aortic heart valve is constantly subjected to pulsatile flow and pressure gradients which, associated with cardiovascular risk factors and abnormal hemodynamics (i.e. altered wall shear stress), can cause stenosis and calcification of the leaflets and result in valve malfunction and impaired circulation. Available options for valve replacement include homograft, allogenic or xenogenic graft as well as the implantation of a mechanical valve. A tissue-engineered heart valve containing living autologous cells would represent an alternative option, particularly for pediatric patients, but still needs to be developed. The present study was designed to demonstrate the feasibility of using a living tissue sheet produced by the self-assembly method, to replace the bovine pericardium currently used for the reconstruction of a stented human heart valve. In this study, human fibroblasts were cultured in the presence of sodium ascorbate to produce tissue sheets. These sheets were superimposed to create a thick construct. Tissue pieces were cut from these constructs and assembled together on a stent, based on techniques used for commercially available replacement valves. Histology and transmission electron microscopy analysis showed that the fibroblasts were embedded in a dense extracellular matrix produced in vitro. The mechanical properties measured were consistent with the fact that the engineered tissue was resistant and could be cut, sutured and assembled on a wire frame typically used in bioprosthetic valve assembly. After a culture period in vitro, the construct was cohesive and did not disrupt or disassemble. The tissue engineered heart valve was stimulated in a pulsatile flow bioreactor and was able to sustain multiple duty cycles. This prototype of a tissue-engineered heart valve containing cells embedded in their own extracellular matrix and sewn on a wire frame has the potential to be strong enough to support physiological stress. The next step will be to test this valve extensively in a bioreactor and at a later date, in a large animal model in order to assess in vivo patency of the graft.

Application Research of Virtual Sludge Technology FreeForm in Character Design

The paper introduces the way of solid modeling and wire frame modeling, described modeling ways from drawing the general outline of the form, to using the general model to make out the general modeling of form, to making the whole effect of the animation by combining with concrete examples which are pf rapid and convenient application value in promoting design speed, enriching expression effect (surface modeling), optimizing design process. It is beneficial to play the design wisdom, give consideration to both economic and social benefits. Its modeling is easy to meet consumer demand for fresh and exaggerated things, and helps to clear the market demand, good commodity modeling and its industrialization prospect.

180 Primary human urothelial cell culture on a matrix of spider silk: A novel technique in bladder reconstruction

Various diseases of the genitourinary tract can cause damage to the bladder and result in urinary retention or incontinence. Treatment options of affected bladders include augmentation cystoplasty, in which the bladder is enlarged by using a piece of intestine. Since the use of intestine in the urinary tract can cause serious adverse effects, new (bio)materials are being tested for bladder reconstruction. However, the ideal (bio)material for reconstruction of the bladder has not yet been discovered, mostly due to mechanical failure in vivo. A promising natural biomaterial is spider silk, which is outstanding in its slow degradation rate and mechanical properties. In this study, we assess the in vitro potential of spider silk as a suitable biomaterial for bladder reconstruction by cultivating primary human urothelial cells (HUCs) on native spider silk matrices. Here, we manufactured dental wire frames which were woven with the dragline silk of female Nephila Clavipes spiders under standardized conditions. Upon sterilization of spider silk frames, HUCs were cultivated on spider silk matrices and evaluated for adhesion, expansion, viability and cellular differentiation. Analysis of cell morphology and filamentous actin in HUCs revealed abundant adhesion sites and bridging of HUCs to spider silk matrices. In addition, qRT-PCRbased analysis of adhesion molecules present in HUCs revealed down-regulation of certain adhesion molecules when HUCs were cultured on spider silk. Expansion of HUCs on spider silk matrices was determined over time using Presto Blue and DAPI cell count in fields of vision and showed that spider silk supports expansion of HUCs. In vitro biocompatibility of spider silk was assessed by culturing HUCs in an extract of spider silk and revealed no cytotoxic effects on HUCs. This is supported by live/dead staining which demonstrated that HUCs were viable when cultured on spider silk matrices. QRT-PCR-based analysis of epithelial-mesenchymal transition, fibrosis and cellular differentiation markers expressed in HUCs when cultured on spider silk showed, besides down-regulation of CD44, no differences compared to control. Flow cytometry-based analysis of urothelial cellular differentiation markers CD90, CD44 and CD49f demonstrated a small subpopulation lower in CD44 expression at protein level when HUCs were cultured on spider silk. These results indicate that spider silk causes HUCs to mature slightly faster, but has no major effects on cellular differentiation of HUCs. Together, results describe a novel biomaterial which supports adhesion, expansion and viability of HUCs. Our study gives new understanding of cellular mechanisms occurring in HUCs when cultured on spider silk and demonstrates that spider silk is a promising biomaterial for bladder reconstruction.

Study on Collapse Numerical Simulation Method of Frame Structures Based on Explicit Dynamics

According to the theory of collapse numerical simulation, the explicit finite element algorithm based on explicit dynamics was chose as the numerical calculation method. And combined with the plane RC frame collapse test and the example of ten layers frame structure, the wire frame model, integrated model and separate model were established and the alternate path method was adopted to study the simulate method of structural collapse. With the comparison of several aspects to the results, the rationality of the numerical simulation method and the applicability of the numerical models were verified respectively. At the same time, according to the complex pre-treatment process to the numerical simulation of structural collapse, an MFC program with the function of exporting APDL file which can generate wireframe models for structural collapse simulation in ANSYS/LS-DYNA was developed using VC++ language with the purpose of offering convenience to the numerical simulation process of structure collapse.

A trained perceptual bias that lasts for weeks

Classical (Pavlovian) conditioning procedures can be used to bias the appearance of physical stimuli. Under natural conditions this form of perceptual learning could cause perception to become more accurate by changing prior belief to be in accord with what is statistically likely. However, for learning to be of functional significance, it must last until similar stimuli are encountered again. Here, we used the apparent rotation direction of a revolving wire frame (Necker) cube to test whether a learned perceptual bias is long lasting. Apparent rotation direction was trained to have a different bias at two different retinal locations by interleaving the presentation of ambiguous cubes with presentation of cubes that were disambiguated by disparity and occlusion cues. Four groups of eight subjects were subsequently tested either 1, 7, 14, or 28 days after initial training, respectively, using a counter-conditioning procedure. All four groups showed incomplete re-learning of the reversed contingency relationship during their second session. One group repeated the counter-conditioning and showed an increase in the reverse bias, showing that the first counter-conditioning session also had a long-lasting effect. The fact that the original learning was still evident four weeks after the initial training is consistent with the operation of a mechanism that ordinarily would improve the accuracy and efficiency of perception.

Superspreaders Versus “Cousin” Non-Superspreaders: Disjoining Pressure in Gravitational Film Drainage

Gravitational drainage of vertical films supported on a wire frame of two superspreaders SILWET L-77 and BREAK-THRU S 278 and their respective "cousin" non-superspreaders SILWET L-7607 and BREAK-THRU S 233 revealed drastic differences. The superspreader films showed complicated dynamic "turbulent"-like interferometric patterns in distinction from the ordered color bands of the "cousin" non-superspreaders, which resembled those of the ordinary surfactants. Nevertheless, the superspreader films stabilized themselves at the thickness about 35 nm and revealed an order of magnitude longer lifetime before bursting compared to that of the "cousin" non-superspreaders. Notably, the superspreaders revealed drastic differences from the non-superspreaders in aqueous solutions with no contact with any solid hydrophobic surface. The self-stabilization of the superspreader films is attributed to significant disjoining pressure probably related to long superspreader bilayers hanging from the free surfaces. The scaling law for the disjoining pressure was found as p(disj)(h) ~ h(-m) (with m ≈ 9-11) for the sufficiently concentrated superspreader solutions, and as p(disj)(h) ~ h(-s) (with s ≈ 6) for more dilute solutions (in both cases, concentrations were above the critical micelle concentration). The non-superspreaders do not possess any significant disjoining pressure even in the films with thicknesses in the 35-100 nm range. The results show that gravitational drainage of vertical films is a useful simple tool for measuring disjoining pressure.

Features classification using geometrical deformation feature vector of support vector machine and active appearance algorithm for automatic facial expression recognition

This paper proposes a method for facial expression recognition in image sequences. Face is detected from the scene and then facial features are detected using image normalization, and thresholding techniques. Using an optimization algorithm the Candide wire frame model is adapted properly on the first frame of face image sequence. In the subsequent frames of image sequence facial features are tracked using active appearance algorithm. Once the model fits on the first frame, animation parameters of model are set to zero, to obtain the shape of model for the neutral facial expression of the same face. The last frame of the image sequence corresponds to greatest facial expression intensity. The geometrical displacement of the Candide wire frame nodes, between the neutral expression frame and the last frame, is used as an input to the multiclass support vector machine, which classifies facial expression into one of the class such as happy, surprise, sadness, anger, disgust, fear and neutral. This method is applicable for frontal as well as tilted faces with angle $$\pm 30\,^{\circ }, \pm 45\,^{\circ }, \pm 60\,^{\circ }$$ ± 30 ? , ± 45 ? , ± 60 ? with respect to y axis.

Role of Ambient Oxygen in the Stabilisation of Single Aluminium Alloy Films

Aluminium-based single films were pulled out of a melt using circular wire frames and characterised with respect to their stability under varied conditions. Pure Al, AlSi9 and AlSi9Mg0.6 alloys as well as particle reinforced composites based on the same alloys but adding different amounts of stabilising SiC or TiB2 particles were prepared. The velocity at which films were drawn was varied to investigate their solidification as well as their oxidation behaviour. In order to study the influence of the oxygen content of the foaming atmosphere a chamber was manufactured that allows for pulling single films under defined conditions. It was found that films without Mg were less stable than Mg-containing ones and even the addition of particles to such Mg-free alloys results in no improvement. In contrast, films made of AlSi9Mg0.6 were more stable and required only a small amount of oxygen (> 200ppm O2), but in general some oxygen has always to be present to obtain a stable film. It was found that the more particles are contained in the composite and the slower the film gets pulled, the lower the required oxygen content is.

Building a better sticky trap: description of an easy-to-use trap and pole mount for quantifying the abundance of adult aquatic insects

AbstractInsect emergence is a fundamental process in freshwaters. It is a critical life-history stage for aquatic insects and provides an important prey resource for terrestrial and aquatic consumers. Sticky traps are increasingly being used to sample these insects. The most common design consists of an acetate sheet coated with a nondrying adhesive that is attached to a wire frame or cylinder. These traps must be prepared at the deployment site, a process that can be time consuming and difficult given the vagaries of field conditions. Our goals were to develop a sturdy, low-cost sticky trap that could be prepared in advance, rapidly deployed and recovered in the field, and used to estimate the flight direction of insects. We used 150-mm Petri dishes with lids. The dishes can be coated cleanly and consistently with Tangle-Trap® adhesive. Deploying traps is simple and requires only a pole set near the body of water being sampled. Four dishes can be attached to the pole using Velcro and aligned in 4 differe...

Survey of Surface Reconstruction Algorithms

Surface reconstruction is a problem in the field of computational geometry that is concerned with recreating a surface from scattered data points sampled from an unknown surface. To date, the primary application of surface reconstruction algorithms has been in computer graphics, where physical models are digitized in three dimensions with laser range scanners or mechanical digitizing probes (Bernardini et al., 1999 [1]). Surface reconstruction algorithms are used to convert the set of digitized points into a wire frame mesh model, which can be colored, textured, shaded, and placed into a 3D scene (in a movie or television commercial, for example). In this paper, we discuss some computational geometry preliminaries, and then move on to a summary of some different techniques used to address the surface reconstruction problem. The coming sections describe two algorithms: that of Hoppe, et al. (1992 [2]) and Amenta, et al. (1998 [3]). Finally, we present other applications of surface reconstruction and a brief comparison for some algorithms in this filed emphasizing on their advantages and disadvantages.

Visual Workshop 2: a model viewer, editor and results display package for the ANSWERS shielding and criticality codes

The goal of Visual Workshop is to be an 'Integrated Development Environment' for preparing, modifying, checking, running and analysing results from the shielding codes MCBEND and RANKERN, the criticality code MONK, and the reactor physics/criticality code WIMS. The functionality is being introduced in stages and this paper announces the release of version 2. The key features of Visual Workshop version 1 included: interactive 2D and 3D ray trace display of the model using the same routines as the analysis code, wire frame display of the model, built in editing, running and diagnostic capabilities and a simple results display. The main additional capabilities of version 2 are: Results display using 2D cell plots, 2D contour plots and 3D iso-surface plots overlaid on the model geometry; and display of event type and location and particle tracks overlaid on the model geometry.

External wire-frame fixation of digital skin grafts: A non-invasive alternative to the K-wire insertion method

Background and AimThe current skin graft fixation methods for digits, including the Kirschner wire insertion technique, can be limited by inadequate or excessive fixation and complications such as infection or secondary injuries. Therefore, the external wire-frame fixation method was invented and used for skin grafting of digits. This study aimed to investigate external wire-frame fixation of digital skin grafts as a non-invasive alternative to the K-wire insertion method. MethodsIn 2005–2012, 15 patients with burn scar contractures on the hand digits received a skin graft that was then fixed with an external wire frame. The intra-operative time needed to make the wire frame, the postoperative time to frame and suture removal, the graft survival rate, the effect of contracture release and the complications were recorded. ResultsIn all cases, the contracture release was 100%. The complete graft survival rate was 98.6%. Four patients had epithelial necrosis in <5% of the total area. There were no other complications such as pressure ulcer or hypoxia of fingers. ConclusionsExternal wire-frame fixation is simple, minimally invasive and a custom-made technique for skin grafting of the fingers. It was designed for its potential benefits and the decreased risk it poses to patients with scar contractures on their fingers. It can be implemented in three phases of grafting, does not affect the epiphyseal line or subsequent finger growth and is suitable for children with multi-digit involvement.

Response and Test of Whole Space Transient Electromagnetic Field in Mine Goaf Water

The transient electromagnetic method (TEM) has sensitive characteristics of low resistivity of water containing. The equivalent plane method based on whole space theory is used in coal mine goaf water TEM detecting. The mine goaf water was forward simulation. The geoelectric model of mine goaf water was equivalented to low resistivity layer thickness. The geoelectric model was forward calculated, and it was differential imaged. Then it found the apparent longitudinal conductance differential imaging reflect the most sensitive. The field experiment was conducted in two mine goaf water in Xiezhuang coal mine. The central loop device was selected as working device. The launch wire frame is length of 2m and 8 turns. A receiving device is receiving probe and the effective area is 212m2. The Water distribution range of goaf water in-300 of the seven mining area in front of retaining wall is large, and the water body is deep.

Preparation and Application of a Self-Thermal and Insulation-Ribbed Floor

With the cementitious composite formwork without being removed, steel wire frame and formwork technology, a self-thermal and insulation-ribbed concrete floor is made. Through the tests of bend-bearing capacity of self-thermal and insulation-ribbed floor, the results show that the loads of the self-thermal and insulation-ribbed floor meet the limits on deflection requirements according to the design of concrete structures. Besides, the floor has a better thermal and soundproof function compare to the ordinary concrete beam and slab, and its comprehensive cost of construction is low.

Three Dimensional Gait Analysis Using Wearable Acceleration and Gyro Sensors Based on Quaternion Calculations

This paper proposes a method for three dimensional gait analysis using wearable sensors and quaternion calculations. Seven sensor units consisting of a tri-axial acceleration and gyro sensors, were fixed to the lower limbs. The acceleration and angular velocity data of each sensor unit were measured during level walking. The initial orientations of the sensor units were estimated using acceleration data during upright standing position and the angular displacements were estimated afterwards using angular velocity data during gait. Here, an algorithm based on quaternion calculation was implemented for orientation estimation of the sensor units. The orientations of the sensor units were converted to the orientations of the body segments by a rotation matrix obtained from a calibration trial. Body segment orientations were then used for constructing a three dimensional wire frame animation of the volunteers during the gait. Gait analysis was conducted on five volunteers, and results were compared with those from a camera-based motion analysis system. Comparisons were made for the joint trajectory in the horizontal and sagittal plane. The average RMSE and correlation coefficient (CC) were 10.14 deg and 0.98, 7.88 deg and 0.97, 9.75 deg and 0.78 for the hip, knee and ankle flexion angles, respectively.

Does Stone Entrapment With "Uro-Net" Improve Ho:YAG Laser Lithotripsy Efficiency in Percutaneous Nephrolithotomy and Cystolithopaxy?: an In Vitro Study

to test the effect of stone entrapment on laser lithotripsy efficiency. Spherical stone phantoms were created using the BegoStone® plaster. Lithotripsy of one stone (1.0 g) per test jar was performed with Ho:YAG laser (365 µm fiber; 1 minute/trial). Four laser settings were tested: I-0.8 J,8 Hz; II-0.2J,50 Hz; III-0.5 J,50 Hz; IV-1.5 J,40 Hz. Uro-Net (US Endoscopy) deployment was used in 3/9 trials. Post-treatment, stone fragments were strained though a 1mm sieve; after a 7-day drying period fragments and unfragmented stone were weighed. Uro-Net nylon mesh and wire frame resistance were tested (laser fired for 30s). All nets used were evaluated for functionality and strength (compared to 10 new nets). Student's T test was used to compare the studied parameters; significance was set at p < 0.05. Laser settings I and II caused less damage to the net overall; the mesh and wire frame had worst injuries with setting IV; setting III had an intermediate outcome; 42% of nets were rendered unusable and excluded from strength analysis. There was no difference in mean strength between used functional nets and non-used devices (8.05 vs. 7.45 lbs, respectively; p = 0.14). Setting IV was the most efficient for lithotripsy (1.9 ± 0.6 mg/s; p < 0.001) with or without net stabilization; setting III was superior to I and II only if a net was not used. Laser lithotripsy is not optimized by stone entrapment with a net retrieval device which may be damaged by high energy laser settings.

Prevention of pea lodging by intercropping barley with peas at different nitrogen fertilization levels

Field pea (Pisum sativum L.) that is grown in pure stands tends to lodge, which may lead to decreased grain yields. Barley (Hordeum vulgare L.) intercropped with peas prevents lodging, but this facilitative effect of the cereal on the pea has rarely been examined. Two two-factorial experiments (Experiment 1 and Experiment 2) were conducted in 2005, 2006, and 2007 to study interactions between barley and a medium-tall, leafy field pea (Wiato cultivar) and between barley and a tall, leafy field pea (Fidelia cultivar). In both experiments, mineral N fertilizer was used at rates of 0, 30, and 60kg of Nha−1. Experiment 1 was conducted to evaluate plant lodging, grain yield, the intercrop yield advantage over pure stands and competition between the intercropped species. Experiment 2 was designed to separate the facilitative effect of the mechanical support provided to the peas by the barley in the intercrop from the effects of competition. In the experiment, groups of four pea plants were grown supported by an iron wire frame to prevent their lodging. The frames were kept in the plots until the peas flowered fully or reached full maturity. Similar groups of legumes were also grown in mixtures with nine barley plants. These treatments permitted the determination of the net benefits to the peas of the mechanical support provided by the added barley between pea flowering and maturity. In Experiment 1, there was little lodging of the pea cultivars in the intercrops, whereas the pure stands lodged severely. In all years, the barley–pea intercrops were more productive than the sole crops (LER>1). The barley–Wiato mixture yielded more grain than the barley–Fidelia mixture in 2005 and 2006. Both mixtures transgressively overyielded in 2006 at the nitrogen fertilizer rate of 30kg of Nha−1, and the barley–Wiato mixture did so at 0kg of Nha−1. Experiment 2 showed that mechanical plant support (facilitation) was more important for the tall cultivar Fidelia than for the medium-tall cultivar Wiato, but Fidelia was the weaker competitor of the two with barley. Increasing the N fertilizer rates decreased the pea tolerance to competition from barley in the intercrop.

Drainage of particle-stabilised aluminium composites through single films and Plateau borders

Liquid metallic alloys with and without stabilizing particles such as TiB2 or SiC were processed to single films or artificial single Plateau borders to clarify the stabilization mechanisms of metallic foams based on the same melts. First, isolated single films were pulled out of a liquid metal by using circular wire frames of various sizes. Modified wire frame structures comprising double or quadruple parallel frames were then used to create artificial metallic Plateau borders. Drainage in single metallic films between two Plateau borders was studied by cutting films vertically and analysing their cross sections. Particle movement in liquid films was observed in-situ via synchrotron X-ray radioscopy. It was found that Mg-free liquid metallic alloys containing stabilising particles are less stable and rupture immediately because of unhindered drainage. In contrast, films made of AlSi9Mg0.6 alloy containing TiB2 or SiC are stable for long holding times. Our study shows that the complexity of drainage and evolution of Plateau borders in true metal foams can be studied by using a simple model system based on a single metallic film between two artificial Plateau borders.