Vertical Fibers Research Articles

Anatomy of the Plantarmedial Hallucal Nerve in Relation to the Medial Approach of the First Metatarsophalangeal Joint

The medial approach has been widely utilized for various pathologies of the first metatarsophalangeal joint. Injury to the plantarmedial hallucal nerve has been cautioned but never been reported. This study evaluated the proximity of the plantarmedial hallucal nerve to the midline and the vertical capsulotomy through the medial approach. Nine fresh cadaver legs were dissected under loupe magnification after AP radiographs were obtained. The distances from the plantarmedial hallucal nerve to the midline and to the plantar extent of the vertical capsulotomy were measured. The nerves were documented for their course, branching, and integrity. The average hallux valgus angle was 10.3 +/- 3.8 degrees (Mean +/- SD). The distances from the nerve to the midline and to the plantar extent of the vertical capsulotomy averaged 10.6 +/- 3.2 mm and 2.4 +/- 1.6 mm. One specimen demonstrated a partial nerve transection. All the nerves were found underneath the crural fascia and covered by vertical fibers investing the plantar fat pad at the level of the metatarsophalangeal joint. They gave off an average of seven terminal branches toward the pulp and tip of the hallux. The plantarmedial hallucal nerve is at risk for injury with the vertical capsulotomy during a medial approach to the first metatarsophalangeal joint due to its proximity to the plantar extent of the vertical capsulotomy. Surgeons should be vigilant in doing the vertical capsulotomy of the first metatarsophalangeal joint especially if the plantarmedial hallucal nerve is not identified.

Fabrication-Tolerant Waveguide Chirped Grating Coupler for Coupling to a Perfectly Vertical Optical Fiber

We report the simulation, fabrication, and measurement results of a waveguide grating coupler that could efficiently couple light between submicrometer-sized planar waveguides and vertical optical fibers. The coupler comprises a section of chirped grating which reduces back reflection and enhances coupling efficiency. Coupling efficiency of over 34% was measured and a 3-dB bandwidth of 45 nm was obtained. An experimental study showed that the coupling efficiency was tolerant to fabrication process fluctuations which may lead to random variations in slot width and the duty cycle of the grating periods.

The symplectic structure of the primary visual cortex

We propose to model the functional architecture of the primary visual cortex V1 as a principal fiber bundle where the two-dimensional retinal plane is the base manifold and the secondary variables of orientation and scale constitute the vertical fibers over each point as a rotation-dilation group. The total space is endowed with a natural symplectic structure neurally implemented by long range horizontal connections. The model shows what could be the deep structure for both boundary and figure completion and for morphological structures, such as the medial axis of a shape.

High efficiency grating coupler between silicon-on-insulator waveguides and perfectly vertical optical fibers

A high-efficiency waveguide-to-fiber grating coupler for silicon-on-insulator waveguides was designed. Perfectly vertical fiber coupling is achieved by using an asymmetric grating structure to suppress the second-order Bragg reflection from the grating. The ability to use a perfectly vertical positioned optical fiber simplifies the packaging of the photonic integrated circuit. A coupling efficiency of 80% at a wavelength of 1.55 microm is obtained.

Field emitters with low turn on electric field based on carbon fibers

Field emitters of vertical carbon fibers on a silicon substrate are fabricated by catalytic chemical vapor deposition. After an ageing process of 150 min, field emission measurement of the fibers is carried out in a vacuum chamber with a base pressure of 5.0 × 10 −4 Pa. The experimental results display that field emission performance of the carbon fibers depends strongly on the vacuum level during the experiments. After the field emission measurement, damage to the carbon fiber field emitters is observed from the scanning electron microscopic images.

Local modeling of the rolling phenomenon in the cell adhesion kinetics: A probabilistic approach

Cell adhesion plays an important role in biology: essentially with regard to immunizing defence and the transport of medicinal substances toward specific zones. The focus is here on the mechanical description of adhesion kinetics, in terms of the failure and creation of connections during the rolling phenomenon. Hence, we consider the case of a single cell, which is linked to a rigid substratum. A 2D model is established. We consider that the contact zone cell-wall is rectilinear and composed of vertical fibers and two horizontal rigid beams (complex cell membrane- fibers-vein wall). These connections are modeled by elastic springs having identical elastic properties (e.g stiffness), but different failure strengths. The cell is subjected to the flow of plasma, which can generate the rolling phenomenon; we accordingly consider two distinct zones, one associated with the failure of the old fibers and one with the creation of the new fibers (in the direction opposite to the flow). Several interactions are taken into account in this model: van der Waals (attractive) and electrostatic (repulsive) forces and the effects of fluid pressure, assimilated into a periodic point force applied to the interface zone. We also study the vibration induced failure in the contact zone without mechanical damping using the principle of virtual work and a failure criterion to establish the equation of motion and the time evolution of the failure (dynamical approach). Rupture of a fiber can occur if the stress applied to the fiber is above a certain limit. These limits are determinated with using a probabilistic approach by use of a spectral method to simulate a stochastic and Gaussian field. Modeling of the creation of new fibers is also achieved by the combination of a dynamical and probabilistic method and a kinematical criterion. On the basis of these elements, numerical simulations are developed, that elucidate the rupture and rolling phenomena.

Organization and Function of the Collagen Fiber System in the Human Temporomandibular Joint Disk and Its Attachments

The collagen fiber organization in the anterior band (AB), intermediate zone (IZ) and posterior band (PB) of the disk of the human jaw joint disk and in its attachments was studied under the polarizing microscope. Observations were made on serially sectioned joints (n = 6) and three sets of disk samples sectioned along mutually perpendicular planes (n = 21). The collagen fiber bundles in all disk regions branch and join or are decussated with other bundles. The fibers of the IZ were oriented generally parallel to the disk surfaces. Most of these fibers extend into the AB and PB where they either join with transverse or vertically oriented fiber groups or pass through the bands into the disk attachments. The lateral branching/decussation angles of fibers in the IZ and adjacent regions of the AB and PB were measured in the central region of four disks. The mean angle for all regions was 28 ± 13°. The mean angles in the region transitional between the IZ and AB and in the anterior region of the IZ were significantly greater than those in the posterior part of the IZ (p = 0.001 and 0.050 for the two comparisons). The large caliber, vertically oriented fibers in the AB, IZ and PB were counted in nine specimens. Disk dimensions were also measured in these specimens. The vertically and transversely oriented bundles were more frequent in the band regions. The number of vertically oriented fiber bundles varied within and between the disk bands. Vertical fiber number in the AB was greater laterally than medially (p = 0.04). In the PB the fiber number was greater than in either the AB or IZ (p = 0.000 for both comparisons) and within the PB itself the fiber number was greater in its thicker, medial half (p = 0.014). The fiber number in the AB and IZ was not different. The thickness of the AB, IZ and PB and disk length was measured in sections located laterally, centrally and medially. No difference in disk length was found across these planes. Statistically significant differences were found in regional disk thickness. In all of the mediolateral planes, the AB and PB were thicker than the IZ and the PB was thicker than the AB (p = 0.000 for all comparisons). The IZ was thicker medially than laterally (p = 0.034). The PB was thicker centrally and medially than laterally (p = 0.002 and 0.001, respectively). PB thickness in its central and medial regions was not different. The findings, combined with other evidence, suggest that the fiber system of the disk serves a stress distribution function and that within the AB and PB, the regions containing the greatest number of vertical fibers may also be the sites of greatest compressive stress during jaw function.

„Bottoming out“ bei Mammaaugmentation - Möglichkeiten der Prävention und Korrektur

Displacement of a breast implant beneath the original submammary fold is known as a rare but, in most cases, difficult to correct complication after augmentation mammaplasty. Suggestions for re-centering the mammary implant range from simple percutaneous sutures to the additional application of expensive alloplastic dermal grafts. Based on the latest findings concerning plastination histology of the fascial system of the breast and in the light of our own clinical experience regarding correction of implant ptosis we have developed a special treatment concept. When placing the implant, the vertical fibers of the submammary fold are saved as a precautionary measure. In cases where there is a risk of possible inferior displacement of the mammary implant, an individually manufactured belt-like bandage is applied for approximately eight weeks postoperatively. In cases requiring the correction of a severe "bottoming out" deformity, we either lift the capsular shell of the implant or, if the fibrous capsule is thin and vulnerable, we use a special capsular flap technique resulting in a hammock that catches the implant at the height of the new submammary fold. Postoperative application of our belt-like bandage is again indispensable.

Observation and modelling of barrel droplets on vertical fibres subjected to gravitational and drag forces

Extensive experimental investigation of the wetting processes of fibre/liquid systems during air filtration (when drag and gravitational forces are acting) has shown many important features, including droplet extension, oscillatory motion, and detachment or flow of drops from fibres as airflow velocity increases. A detailed experimental study of the aforementioned processes was conducted using glass filter fibres and H 2O aerosol, which coalesce on the fibre to form barrel droplets with small contact angles. The droplets were predominantly observed in the Reynolds transition (or unsteady laminar) flow region. The droplet oscillation appears to be induced by the onset of vortexes in the flow field around the droplet as the increasing droplet size increases the Reynolds number. Flow in this region is usually modelled using the classical two-dimensional Karman vortex street, and there exist no 3D equivalents. Therefore to model such oscillation it was necessary to create a new conceptual model to account for the forces both inducing and inhibiting such oscillation. The agreement between the model and experimental results is acceptable for both the radial and transverse oscillations.

The longtime behavior of a nonlinear Reissner–Mindlin plate with exponentially decreasing memory kernels

In this paper we investigate the longtime behavior of the mathematical model of a homogeneous viscoelastic plate based on Reissner–Mindlin deformation shear assumptions. According to the approximation procedure due to Lagnese for the Kirchhoff viscoelastic plate, the resulting motion equations for the vertical displacement and the angle deflection of vertical fibers are derived in the framework of the theory of linear viscoelasticity. Assuming that in general both Lame's functions, λ and μ, depend on time, the coupling terms between the equations of displacement and deflection depend on hereditary contributions. We associate to the model a nonlinear semigroup and show the behavior of the energy when time goes on. In particular, assuming that the kernels λ and μ decay exponentially, and not too weakly with respect to the physical properties considered in the model, then the energy decays uniformly with respect to the initial conditions; i.e., we prove the existence of an absorbing set for the semigroup associated to the model.

Three-dimensional computed tomographic images of pelvic muscle in anorectal malformations

Purpose The anatomy of the pelvic flower muscles based on investigation of gross section slides of a specimen does not always correspond with those described by Pena. Therefore, we restudied the anatomy with 3-dimensional (3D) images of the pelvic muscle produced with computed tomography. Methods Thirty-eight patients with anorectal malformations before anorectoplasty were investigated with a multi–detector row helical computed tomography (MRH-CT). Images of the pelvic part were obtained with a slice thickness of 1 mm and a reconstruction pitch of 0.5 mm. A 3D reconstruction was made with the volume rendering method. Lateral views of the 3D CT reconstructed images of the pelvic muscle were compared with the same views of the type corresponding to Pena's schematic drawings in the literature. Results Study of the 3D reconstructions demonstrated that the pelvic muscles of each type were less uniform than the ones described by Pena. There was a great difference even in the same type of anatomy. The differences between the 3D image and the description by Pena were most notable in the high type and particularly in the description of the vertical fibers and the parasagittal muscles. Conclusions A 3D image with MRH-CT can provide useful preoperative information about the anatomy of the pelvic flower muscles in each case.

First reported occurrence of wewokellid sponges (Calcarea, Heteractinida) from the Permian of central Iran

The new calcisponges Regispongia fluegeli n. sp., and Iranospongia circulara n. gen. n. sp., are described from central Iran. These are the first heteractinid sponges reported from the Permian of the region. These wewokellid sponges are large, irregularly cylindrical forms with a distinct axial spongocoel. The calcareous spicular skeletons of both taxa have been overgrown and are recrystallized. However, the preserved skeleton of Regispongia fluegeli does include large polyactines in the main endosomal layer and small octactines and possibly other polyactine spicules in both the relatively massive dermal layer and the distinct, delicately spiculed, gastral layer. Iranospongia is characterized by a discontinuous ring of vertical exhalant canals interior to the dense dermal layer, and by an interior skeleton net that includes common coarse vertical fibers. Individual spicules in Iranospongia are commonly obscured, but locally some remnants of possible polyactines occur in outer parts of the skeleton.

Sodium Channel β1 Subunits Promote Neurite Outgrowth in Cerebellar Granule Neurons

Many immunoglobulin superfamily members are integral in development through regulation of processes such as growth cone guidance, cell migration, and neurite outgrowth. We demonstrate that homophilic interactions between voltage-gated sodium channel beta1 subunits promote neurite extension in cerebellar granule neurons. Neurons isolated from wild-type or beta1(-/-) mice were plated on top of parental, mock-, or beta1-transfected fibroblasts. Wild-type neurons consistently showed increased neurite length when grown on beta1-transfected monolayers, whereas beta1(-/-) neurons showed no increase compared with control conditions. beta1-mediated neurite extension was mimicked using a soluble beta1 extracellular domain and was blocked by antibodies directed against the beta1 extracellular domain. Immunohistochemical analysis suggests that the beta1 and beta4 subunits, but not beta2 and beta3, are expressed in cerebellar Bergmann glia as well as granule neurons. These results suggest a novel role for beta1 during neuronal development and are the first demonstration of a functional role for sodium channel beta subunit-mediated cell adhesive interactions.

Observation and modelling of clamshell droplets on vertical fibres subjected to gravitational and drag forces

Extensive experimental investigation of the wetting processes of fibre–liquid systems during air filtration (when drag and gravitational forces are acting) has shown many important features, including droplet extension, oscillatory motion, and detachment of drops from fibres as airflow velocity increases, and also movement or flow of droplets along fibres. A detailed experimental study of the processes was conducted using stainless steel filter fibres and H 2O aerosol, which coalesce on the fibre to form clamshell droplets. The droplets were predominantly observed in the Reynolds transition flow region, since this is the region where most of the above features occur. The droplet oscillation is believed to be induced by the onset of the transition from laminar to turbulent flow as the increasing droplet size increases Reynolds number for the flow around the droplet. Two-dimensional flow in this region is usually modelled using the classical Karman vortex street, however there exist no 3D equivalents. Therefore to model such oscillation it was necessary to create a new conceptual model to account for the forces both inducing and preventing such oscillation. The agreement between the model and experimental results is very good for both the radial and transverse oscillations.

EVALUATION OF THE PLAYING SURFACE HARDNESS OF AN INFILLED SYNTHETIC TURF SYSTEM

New configurations of synthetic turf, infilled systems, have been introduced into the market place. These infilled systems are comprised of vertical fibers that are much longer than traditional synthetic turf and can be filled with sand and crumb rubber (infill media). The objectives of this study were to evaluate the surface hardness of varying configurations of an infilled synthetic turf system called SofSportTM under wet and dry conditions. Specifically, we wanted to determine 1) the effect of underlying pad thickness and type, infill media depth, sand sizes, and sand to crumb rubber ratio, on surface hardness as measured by the F355 method and the CIT and 2) compare the F355 method with the CIT to determine if one method is preferred when testing synthetic infill systems. Surface hardness differences between pad thickness and types were small but all pad treatments had lower surface hardness values compared to the no-pad treatments. Infill media depth did not affect surface hardness under dry conditions. Under wet conditions, the 38-mm infill media depth resulted in lower surface hardness than the 25mm depth. The mixing of sand and crumb rubber infill media resulted in lower surface hardness values than sand or crumb rubber alone. When mixed with crumb rubber, finer sands measured higher in surface hardness than coarser sands. Under the conditions of this study the relationship between the Gmax values generated by the F355 method can be compared to the values generated by the Clegg Impact Tester using the regression equation F355 x 0.66 9.3 = Clegg Impact Tester. The regression coefficient for this equation was 0.95 and indicates that the Clegg Impact Tester would be a suitable device to measure the surface hardness of Sofsport installations. INTRODUCTION Since the introduction of synthetic turf in 1966, numerous studies have been conducted to evaluate the safety and playability of synthetic surfaces. These studies have included material tests on the traction and hardness of these surfaces (Valiant, 1990; Martin, 1990) as well as epidimeological studies that have counted athlete injuries on synthetic versus natural turfgrass (Powell and Schootman, 1992; Powell, and Schootman, 1993). Different methods of measuring playing surface hardness have been developed for synthetic turf versus natural turfgrass surfaces. For synthetic turf surfaces the U.S.A. standard is the F355 method (American Society for Testing and Materials, 2000a). For natural turfgrass the standard method is the Clegg Impact Tester (CIT) (American Society for Testing and

Intra-Abdominal Pressure and Activation of Abdominal Muscles in Highly Trained Participants During Sudden Heavy Trunk Loadings

Ten participants were exposed to heavy sudden trunk loads as they might occur during patient handling. The aim was to observe if well-trained men and women use their full rate of intra-abdominal pressure (IAP) development when exposed to heavy sudden trunk loads. Further, to elucidate to what degree the rectus abdominus muscle is activated when the IAP is developed. Well-trained judo fighters are used to heavy sudden trunk loads and can produce a high IAP. It is unknown whether they use their full potential. IAP can increase the spinal stability and has been suggested to unload the spine. The unloading effect will, however, disappear if the development of the IAP demands substantial activity in the vertical fibers of the abdominal muscles. Five male and five female well-trained judo and jujitsu fighters were exposed to heavy sudden trunk loadings through imitated patient handling situations where the patient fell and the fighters should hold the patient and prevent the fall. IAP was measured with a catheter in the stomach. Along with the IAP measurement, EMG was measured on the abdominal muscles, and the load on the low back was quantified by a three-dimensional dynamic biomechanical calculation of the torques at the L4-L5 joint. The well-trained judo fighters did not use their full potential of the IAP development when exposed to the heavy sudden trunk loads, but the women had to use a higher level of their IAP and extension torque capacity to comply with the heavy loads. The rectus abdominus muscle does not contribute to the IAP development when the trunk is exposed to a sudden heavy load.

Three-dimensional image reconstruction of an anorectal malformation with multidetector-row helical computed tomography technology.

The presentation of the surgical anatomy of anorectal malformation by standard anatomical figures is not suitable for individual anorectoplasty. It is essential to understand the anatomy of the pelvic muscle (striated muscle complex: SMC) including the external anal sphincter and their three-dimensional (3D) configuration in each patient. Thus, we studied the SMC three-dimensionally with multidetector-row helical computed tomography (MRH-CT) preoperatively, and evaluated its usefulness. Fourteen patients with anorectal malformations before anorectoplasty (types: high n=6, intermediate n=2, low n=6) and two patients without anorectal malformations as controls (total: male n=8, female n=8) were investigated. An image of pelvic region was prepared with a slice thickness of 0.5 mm and a reconstruction pitch of 0.5 mm. A 3D reconstruction on a conventional personal computer (PC) was made with a volume rendering method, and assisted by our own software. The SMC was analyzed with three modified modes of 3D reconstruction corresponding to the surrounding tissues. A length of the parasagittal muscle, and both the sagittal and transverse width of the vertical fibers in the SMC at the connection to the parasagittal muscle were measured on a 3D image and then compared among three different types and controls. To eliminate variations in age, a length index was used to allow comparison. The 3D configuration of the SMC was different in every case. The arranged image mode, which displayed the SMC and the pelvic bones simultaneously, enabled to use conventional knowledge in cysto-urethrography. The length of the parasagittal muscle was longest in the high type but the width of the vertical fibers was smallest. Anatomical figures of the SMC including the external anal sphincter were clearly demonstrated on a PC in every anorectal malformation by our program. A 3D reconstruction image provides positional information on the SMC for the body surface and pelvic bone at the same time. Both a 3D image and positional information with MRH-CT offers the surgeon a simulated operative profile of the SMC superior to CT or magnetic resonance imaging slices alone.

Intervertebral disk prosthesis uses reverse osmosis

Various three-dimensional fabrics (3-DFs) woven with a triaxial three-dimensional (3A-3D) structure in which the warps, wefts and vertical fibres are three-dimensionally orientated with orthogonal, off-angle, cylindrical or complex fibre alignments using a single long fibre, which may be one of several kinds of fibres, have been developed. The physical strengths and behaviour of these fabrics under different external forces were measured for such stress–strain relationships as compressive, tensile and cyclic bending, compressing torsional and compressive tensile systems to evaluate the effect of the continuous loading caused by living body movements over a long period of time. The 3-DFs led to downward convex ‘J’-shaped curves in stress–strain profiles, because they were markedly flexible at low strain levels, but became rigid as strain increased. In this behaviour they reflected the behaviour of natural cartilage rather than that of conventional artificial biomaterials. There were also some 3-DFs that showed hysteresis loss curves with quite similar mechanical strengths and behaviour to natural intervertebral discs with regard to the compressive-tensile cyclic stress and showed little variation from the first ‘J’-shaped hysteresis profile even after 100, 000 deformation cycles. Accordingly, it has been shown that, without a doubt, 3-DFs can be effective implants possessing both design and mechanical biocompatibilities as well as the durability necessary for long-term implantation in the living body. The surface of bioinert linear low-density polyethylene coating on multifilaments of ultra-high molecular weight polyethylene, a constructional fibre of 3A-3D weaving, was modified by treatment with corona-discharge and spray-coating of unsintered hydroxyapatite powder to impart chemical (surface) compatibility and biological activity, respectively. Since the modified surface of the 3-DF was ascertained to have affinity and activity with simulated body fluid, an orthogonal 3-DF block was implanted in the tibia of a rabbit. Sufficient surrounding tissues entering into the textural space of the 3-DF could be observed at 4 weeks after implantation and the load necessary to break the block away from the bone reached a high value at 8 weeks. These results decisively showed that the 3-DFs could also acquire chemical (surface) and biological biocompatibilities and bonding capacity with bone and soft tissues through modification of the surface of the constructional fibre. The 3-DFs have definite potential in such applications as novel and effective artificial articular cartilages, intervertebral discs, menisci and materials for osteosynthesis and prosthesis, and the like.

Rostellar apparatus of Fernandezia spinosissima (von Linstow, 1894) (Cestoda, Cyclophyllidea, Davaineidae): microanatomy and fine structure

AbstractThe rostellar apparatus of Fernandezia spinosissima is examined by light and transmission electron microscopy. It is described as composed of rostellum, pseudoproboscis, and two groups of glandular syncytia, one in the rostellum and the other inwards to the rostellum and the pseudoproboscis. The rostellum is a discoid cushion with muscular walls. There are numerous thin vertical muscular fibres and glandular syncytia inside it. Its tegument has slender microtriches. Peripherally, the rostellum is encircled by thin muscle fibres that protrude anteriorly between rostellar hooks and group posteriorly to form retractors. The rostellar hook guards are associated with a complicated network of muscles and nerves. The pseudoproboscis is a thick‐walled ring around the apical part of the scolex adjacent to the rostellum. Its tegument has microtriches with modified spines that are interpreted as accessory spines. The walls of the pseudoproboscis possess a loose structure of parallel muscular fibres and glandular processes. The glandular syncytia, interpreted as modified tegumental perikarya, have basophilic cytoplasm and stain positively for protein and carbohydrate. They form cellular processes, which protrude to reach to the tegument. These results provide structural details characterising one of the rostellar types recognized in the order Cyclophyllidea, i.e. the davaineid rostellar apparatus.

Demonstration of Primary and Secondary Muscle Fiber Architecture of the Bovine Tongue by Diffusion Tensor Magnetic Resonance Imaging

The myoarchitecture of the tongue is comprised of a complex array of muscle fiber bundles, which form the structural basis for lingual deformations during speech and swallowing. We used magnetic resonance imaging of the water diffusion tensor to display the primary and secondary fiber architectural attributes of the excised bovine tongue. Fiber orientation mapping provides a subdivision of the tongue into its principal intrinsic and extrinsic muscular components. The anterior tongue consists of a central region of orthogonally oriented intrinsic fibers surrounded by an axially oriented muscular sheath. The posterior tongue consists principally of a central region of extrinsic fibers, originating at the inferior surface and projecting in a fan-like manner in the superior, lateral, and posterior directions, and lateral populations of extrinsic fibers directed posterior-inferior and posterior-superior. Analysis of cross-fiber anisotropy indicates a basic contrast of design between the extrinsic and the intrinsic fibers. Whereas the extrinsic muscles exhibit a uniaxial architecture typical of skeletal muscle, the intrinsic core muscles, comprised of the verticalis and the transversus muscles, show strong cross-fiber anisotropy. This pattern is consistent with the theory that the tongue's core functions as a muscular hydrostat in that conjoint contraction of the transverse and vertical fibers enable the tissue to expand at right angles to these fibers. These findings suggest that three-dimensional analysis of diffusion tensor magnetic resonance imaging provides a structural basis for understanding the micromechanics of the mammalian tongue.