Lengths Of Bundles Research Articles

Anatomic double-bundle transtibial anterior cruciate ligament reconstruction restores graft length changes but leads to larger graft bending angles.

The purpose of this study was to evaluate the femoral tunnel position using a modified anatomic transtibial (TT) double-bundle anterior cruciate ligament reconstruction (DBACLR) and to investigate the knee kinematics, graft length and graft bending angle following DBACLR. Ten patients who underwent DBACLR using the modified TT technique were included in the study. All patients performed a single-legged lunge under a dual fluoroscopic imaging system to assess the 6 degrees of freedom tibiofemoral kinematics. Femoral tunnel position was evaluated via postoperative three-dimensional (3D) computed tomography. The area centroids of anteromedial (AM) and posterolateral (PL) bundles were determined on 3D knee models. The lengths of AM and PL bundles, as well as graft bending angle at the femoral tunnel aperture, were measured by created virtual fibres. The reconstructed knee rotated more externally compared with the contralateral knee between 0° and 60° (p ≤ 0.049). There is no significant difference in the length change of AM bundle (n.s.) and PL bundle (n.s.) between the two sides from 0° to 120° during the lunge motion. The maximum graft bending angle at the femoral tunnel aperture occurred at 0° of knee flexion, with the AM graft bending angle was 72.6° ± 9.0° and the PL graft bending angle was 90.3° ± 9.7°. The modified TT technique used in this study could achieve anatomical ACL reconstruction, restoring graft length change patterns compared to contralateral knees. However, residual rotational instability of the reconstructed knee was observed after DBACLR, despite achieving anatomic tunnel placement. Therefore, double-bundle reconstruction may not sufficiently address the persistent rotational instability of the knee. Additionally, larger graft bending angles at the femoral tunnel aperture were found with the modified TT technique. Therefore, further improvement to the TT technique should focus on reducing the graft's curvature while maintaining the anatomical properties of the knee joint. The findings of this study highlight the need for improved surgical techniques to address residual rotational instability and optimise graft curvature. These improvements are crucial for enhancing patient outcomes and long-term joint function following ACL reconstruction. Level II.

Bamboo as a natural optimized fiber reinforced composite: interfacial mechanical properties and failure mechanisms

Bamboo is a typical natural fiber-reinforced composite with an optimized distribution of vascular bundles as reinforcement and parenchyma tissues as bio-matrix. The interfacial bonding performance between vascular bundles and parenchyma tissue is critical for the mechanical properties and failure mechanisms of bamboo. This study employed pull-out tests to determine the interfacial shear strength (IFSS) between bamboo vascular bundles and parenchyma tissue and evaluate the critical embedded lengths () of vascular bundles. The effects of embedded vascular bundle lengths on interfacial strength and failure behaviors were also investigated. The results revealed a value of 2.51 mm, lower than the majority of plant fiber-reinforced composite materials, with an IFSS of around 20 MPa, surpassing most artificial bamboo fiber composites. The pull-out process of the vascular bundles involved elasticity, debonding, and sliding friction stage, where debonding energy absorption (DEA) outweighed frictional energy absorption (FEA) and increasing with embedded length. The primary failure features include interfacial debonding, parenchyma tissue ripping, delamination of fiber thin layers, and fiber breakage. Moreover, the parenchyma cells between the two fiber sheaths and at the top of the bamboo block readily detached. The interfacial failure mechanisms of bamboo included debonding, reinforcement, and matrix failure, with the proportions varying as the embedded length increased. Quantitative analysis of the interfaces structure and mechanical properties between vascular bundles and parenchyma tissues could provide a reference for the biomimicry of bamboo structures and the manufacturing of natural fiber-reinforced composite materials.

Structural and functional differences between bundles of different lengths: A corpus-driven study.

This pilot study aims to investigate the differences between varying lengths of bundles in structure and function by comparing the 100 most frequent three-, four-, and five-word bundles in a self-built corpus of dissertations which contains about 3.5 million words. The findings reveal considerable variances between bundles of different lengths in terms of both structure and function. In general, the variances between three-and four-word bundles are greater than those between four-and five-word bundles, and three-and five-word bundles. Structurally, three-and four-word bundles differ significantly in all six main categories. Four-and five-word bundles vary in five categories, while three-and five-word bundles are only different in four categories. Functionally, noticeable variances were observed in research-, text- and participant-oriented bundles between three-and four-word bundles, and three-and five-word bundles. However, four-and five-word bundles only differ significantly in text- and participant-oriented bundles. Interestingly, bundles of varying lengths also vary in patterns that are used to perform the same functions. The results of this study might inform researchers that they need to take bundle lengths into consideration when making generalizations of their findings or comparing bundles between various studies.

Whole-Brain Propagation Delays in Multiple Sclerosis, a Combined Tractography-Magnetoencephalography Study.

Two structurally connected brain regions are more likely to interact, with the lengths of the structural bundles, their widths, myelination, and the topology of the structural connectome influencing the timing of the interactions. We introduce an in vivo approach for measuring functional delays across the whole brain in humans (of either sex) using magneto/electroencephalography (MEG/EEG) and integrating them with the structural bundles. The resulting topochronic map of the functional delays/velocities shows that larger bundles have faster velocities. We estimated the topochronic map in multiple sclerosis patients, who have damaged myelin sheaths, and controls, demonstrating greater delays in patients across the network and that structurally lesioned tracts were slowed down more than unaffected ones. We provide a novel framework for estimating functional transmission delays in vivo at the single-subject and single-tract level.SIGNIFICANCE STATEMENT This article provides a straightforward way to estimate patient-specific delays and conduction velocities in the CNS, at the individual level, in healthy and diseased subjects. To do so, it uses a principled way to merge magnetoencephalography (MEG)/electroencephalography (EEG) and tractography.

Computational study of kinematics of the anterior cruciate ligament double-bundle structure during passive knee flexion–extension

The anterior cruciate ligament (ACL) comprises an anteromedial bundle (AMB) and posterolateral bundle (PLB). Cadaver studies showed that this double-bundle structure exhibits reciprocal function during passive knee flexion–extension, with the PLB taut in knee extension and the AMB taut in knee flexion. In vivo measurements indicated that straight-line lengths of both bundles decrease with increasing knee-flexion angle (KFA). To interpret these seemingly conflicting facts, we developed a computational ACL model simulating the kinematics of the double-bundle structure during passive knee flexion–extension. Tibial and femoral shapes were reconstructed from computed-tomography images of a cadaver knee and used to construct an idealized model of an ACL including its bundles at the tibiofemoral joint. The ACL deformations at various KFAs were computed by finite element analysis. Results showed that the PLB was stretched in knee extension (KFA = 0∘) and slackened with increasing KFA. The AMB was stretched in knee extension (KFA = 0∘) and remained stretched on the medial side when the knee flexed (KFA = 90∘), but its straight-line length decreased with increasing KFA. These findings are consistent with cadaver and in vivo experimental results and highlight the usefulness of a computational approach for understanding ACL functional anatomy.

Toxicity evaluation of waste effluent from cassava-processing factory in lagos state, nigeria using the <i>Allium cepa</i> assay

Mutagenic and genotoxic effects of cassava wastewater (CWW) were investigated by assay of Allium cepa root meristematic cells. The physicochemical parameters of the wastewater samples were also determined. In Allium root growth inhibition test, experimental onion bulbs were cultivated in various concentrations of the CWW and distilled water was used as a negative control. After 72 h, the root tips from the treated bulb were processed for cytological studies by orcein squash technique. The mean lengths of root bundles were obtained and effective concentration (EC) values calculated. The cytotoxic effects on the onion root tips showed strong growth retardation at high concentrations of the effluent with EC value of 5.67%. The mitotic index (MI) 50 rapidly decreased with increasing effluent concentration compared to control. There was significant increase in frequency of chromosome aberrations (stickiness, c-mitosis, vagrant, bridged fragment, binuclei, multipolar anaphase, attached chromosome and laggard chromosome) in root tip meristem cells of Allium cepa at all tested concentrations. At lower concentrations (0.005%), binuclei, (0.5%), vagrant chromosome and (1.0%), bridged fragment were the most common aberrations observed while at higher concentrations, (100 %), c-mitosis, vagrant and bridged fragment were the typical aberrations observed. The results indicate that the effluent samples collected were highly mutagenic. The results of physicochemical analysis revealed that the concentrations of some parameters (turbidity, chemical oxygen demand (COD), biological oxygen demand (BOD), conductivity, total dissolved solid (TDS), total suspended solid (TSS), sulphate, nitrate, phosphate and metals-copper, cobalt, chromium, iron, manganese, magnesium, nickel, cadmium, lead, sodium, potassium and calcium) were above the maximum permissible limit set by world health organization (WHO) and could partly be correlated with the toxicity of wastewater. The findings indicate that the substances contained in the cassava effluents may be toxic to living organisms and may pollute the environment if untreated. Keywords : Mutagenicity, genotoxicity, cassava wastewater, chromosomal aberration, mitotic index, cyanide, Allium cepa.

Effect of discontinuities in bamboo fibre reinforced epoxy composites

This paper performs a systematic study of the effect of various unidirectional fibre patterns, ranging from different overlapping lengths of adjacent fibre bundles to a complete randomization of the position of individual fibre ends. The study is benchmarked with the mechanical behaviour of a fully continuous unidirectional bamboo fibre-epoxy composite and will show the feasibility of using UD discontinuous technical bamboo fibres in continuous preforms for high-end composites applications. The study shows that the tensile stiffness is hardly influenced by the discontinuity patterns, while the introduction of randomized fibre end discontinuities (individual fibres with segment length 50 mm) leads to a preservation of 85% of the longitudinal tensile strength in comparison with a UD continuous bamboo fibre composite.

Length Difference of Anteromedial and Posterolateral Bundles of Anterior Cruciate Ligament in Flexion and Extension (Cadaver Study)

We aimed to measure lengths of both anteromedial (AM) and posterolateral (PL) bundles of anterior cruciate ligament (ACL) in flexion and extension, and analyse statistically. 20 knees of 10 human cadavers were studied in Republic of Turkey Ministry Of Justice Forensic Medicine Institute. All the subjects were male (100%). An anterior longitudinal incision was made and After passing subcutaneous tissue, knee joint was visualized with a medial parapatellar approach. Lengths of both AM and PL bundles of ACL in flexion and extension were measured in millimetres with flexible ruler scale. Data was analysed statistically. Wilcoxon test was used for statistical analysis. Mean age was 46.5 (32-62). A statistically significant difference was seen in lengths of both AM and PL bundles of ACL in flexion and extension (p<0.05). Difference in lengths of bundles of AM and PL in flexion and extension is statistically significant. Whereas, any statistical difference was not noted in comparison of length differences among bundles during flexion and extension (z=0.085, p=0.932). Difference in lengths’ of bundles of AM and PL in flexion and extension was seen statistically significant in our study. In single-bundle technique, only AM bundle of ACL is reconstructed. Besides, both AM and PL bundles of ACL are reconstructed in double-bundle technique. AM and PL bundles have distinct features and lengths in different flexion degrees. We emphasize to review this entity while determining reconstruction technique for ACL-deficient patients.

Comparison of BCF-10, BCF-12, and BCF-20 Scintillating Fibers for Use in a 1-Dimensional Linear Sensor

One-dimensional fiber-bundle arrays may prove useful in a number of radiation sensing applications where radiation detection over large areas is needed. Tests have been performed to evaluate the light generation and transmission characteristics of 15-meter long, 10-fiber bundles of BCF-10, BCF-12, and BCF-20 scintillating fibers (Saint Gobain) exposed to collimated gamma-ray sources. The test set-up used one R9800 (Hamamatsu) photomultiplier tube (PMT) at each end, with a high-speed waveform digitizer to collect data. Time constraints were imposed on the waveform data to perform time-of-flight analysis of the events in the fiber bundles, eliminating spurious noise pulses in the high gain PMTs and also allowing 1-dimensional localization of interactions along the lengths of the fiber bundles. Measurements show that the spatial response of these three fibers is linear over at least 15-m lengths and that, with the equipment used here, the spatial resolution for events irradiating 1 cm of fiber (using a collimated source) ranges from 50 cm to 60 cm over the entire length of the bundles. The efficiency for detecting events varies along the length of the arrays, with the sensitivity at the midpoint (half of the distance) of an array ranging from ~ 2X to ~ 3X the efficiency at the ends, depending on the length of the fiber-bundle array and the self-absorption factor for each fiber's scintillation light. Compared to prior work, a 20-fold improvement in detection sensitivity has been shown for this technique, most likely due to improved optical coupling and improved signal analysis.

In vivo length patterns of the medial collateral ligament during the stance phase of gait

The function of the medial collateral ligament (MCL) during gait has not been investigated. Our objective was to measure the kinematics of the medial collateral ligament during the stance phase of gait on a treadmill using a combined dual fluoroscopic imaging system (DFIS) and MRI technique. Three-dimensional models of the knee were constructed using magnetic resonance images of 7 healthy human knees. The contours of insertion areas of the superficial MCL (sMCL) and deep MCL (dMCL) on the femur and tibia were constructed using the coronal plane MR images of each knee. Both the sMCL and the dMCL were separated into 3 portions: the anterior, mid, and posterior bundles. The relative elongation of the bundles was calculated using the bundle length at heel strike (or 0% of the stance phase) as a reference. The lengths of the anterior bundles were positively correlated with the knee flexion angle. The mid-bundles of the sMCL and dMCL were found to function similarly in trend with the anterior bundles during the stance phase of the gait and their lengths had weak correlations with the knee flexion angles. The elongations of the posterior bundles of sMCL and dMCL were peaked at mid-stance and terminal extension/pre-swing stance phase. The lengths of the posterior bundles were negatively correlated with the knee flexion during the stance phase. The data of this study demonstrated that the anterior and posterior bundles of the sMCL and dMCL have a reciprocal function during the stance phase of gait. This data provide insight into the function of the MCL and a normal reference for the study of physiology and pathology of the MCL. The data may be useful in designing reconstruction techniques to better reproduce the native biomechanical behavior of the MCL. IV.

ChemInform Abstract: Ultrafine Fibers Formed in Electric Fields.

Abstract We describe the preparation of several materials in the form of free-standing ultrafine fibers. The materials are made by evaporating material in an inert gas in the presence of electric fields. Fiber diameters are typically 100–300 A and irregular. Lengths of fibers or fiber bundles extend up to 10 cm. Materials range from transition metals, non-transition metals, semimetals and semiconductors. In most cases, they appear to be the smallest free-standing microwires of these lengths that have been made from these materials.

Preparation of vertically aligned bundles of Mo6S9−xIx (4.5

In this paper we describe a method for growing vertically aligned bundles of Mo6S9−xIx (4.5<x<6) nanowires perpendicular with respect to the substrate. In this efficient method, a one-step synthesis directly from molybdenum, sulphur and iodine in the temperature gradient conditions is used. Bundles with similar lengths could be grown on quartz or conductive materials like molybdenum foil at the temperature of around 1040K. X-ray diffraction (XRD), scanning electron spectroscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the obtained bundles of nanowires. Due to the similar lengths of the aligned bundles and their easiness to disperse in some polar solvents, this material could potentially be used also for applications like building blocks in nanodevices.

Structural control of icicle-like carbon nanotube forest in heterogeneous catalysis growth with high voltage corona discharge

Icicle-like carbon nanotube (CNT) forest, i.e., discrete bundles of CNTs in free standing forms, can be synthesized at a tip surface of tungsten wire via heterogeneous catalysis together with corona discharge in H 2–C 2H 4 mixture at atmospheric pressure. The influences of several parameters in the synthesis condition on the product structures were investigated. It was found that there was an optimized temperature-range to synthesize the icicle-like structure,400–600 °C, and the increase of temperature caused the increase of CNT-diameter. It was observed that the discharge current affected the straightness of CNTs. It was also found that the increase of the ethylene flow rate caused the increase of the height of the CNTs bundles. The lengths of CNTs bundles were limited even when their growth process was continued due to the limited lifetime of the catalyst.

Persistence Length and Nanomechanics of Random Bundles of Nanotubes

A connection between the stiffness of carbon nanotubes (CNT) and their mesoscopic physical behaviour is presented. Persistence lengths of CNT and bundles are calculated and shown to be in macroscopic range (0.03–1 mm for an individual tube), exceeding by many orders of magnitude the typical diameters (around 1–3 nm). Consequently, thermal fluctuations can be neglected when scaling analysis is applied to randomly packed (as produced) CNT network, leading to an approximate equation of state for such material. Beyond the linear elasticity, the outmost CNT are shown to gradually split from the bent bundles; this permits access of solvent or reacting species to the CNT walls, an important mechanism promoting solubilization and chemical functionalization of nanotubes.

Genotoxicity of Oil Field Wastewater in Nigeria

were cultivated in various concentrations of the wastewater, and after 48 h one root tip from each bulb was harvested and processed for cytological studies by the aceto-orcein squash technique. After 96 h, mean lengths of root bundles were obtained and the Effect Concentration (EC) values calculated. Treatment with wastewater resulted in significant dose- dependent root growth inhibition.

Direct synthesis of long single-walled carbon nanotube strands.

In the processes that are used to produce single-walled nanotubes (electric arc, laser ablation, and chemical vapor deposition), the typical lengths of tangled nanotube bundles reach several tens of micrometers. We report that long nanotube strands, up to several centimeters in length, consisting of aligned single-walled nanotubes can be synthesized by the catalytic pyrolysis of n-hexane with an enhanced vertical floating technique. The long strands of nanotubes assemble continuously from arrays of nanotubes, which are intrinsically long.

The enigma of fish ear diversity

There are substantial interspecific differences in the gross anatomy of fish inner ears, including the relative size of the different end organs and the sizes and shapes of their otoliths and sensory epithelia. Differences also occur at finer structural levels and include the orientation patterns of the ciliary bundles on the sensory hair cells. There is also substantial structural variation along the lengths of a single sensory epithelium. This includes not only the mode of contact between the sensory epithelium and the otolith, but also the lengths of the ciliary bundles on the hair cells, and the ultrastructure of the hair cell bodies themselves. The functional significance of the interspecific differences in ear structure is far from being understood, but it may reflect the evolution of different ways to do the same basic kinds of peripheral signal processing, or different kinds of signal processing. We also do not understand the functional importance of the intraepithelial differences, although they may suggest variance in signal processing along the lengths of single epithelia. This paper will consider all of these differences, and suggest ways in which we might think about their functional significance.

Sarcomere lengths of thick skeletal muscle specimens measured under an epi-illumination-type polarization microscope.

The purpose of this study was to measure sarcomere lengths of thick muscle fiber bundles at resting and at isometric tetanic contractions. We developed a novel measurement system using an epi-illumination-type polarization microscope and an image processing algorithm using an ellipse-type Gabor filter. Images with striation patterns of frog skeletal muscle were obtained by the microscope and the image processing algorithm. Individual lengths of 10 consecutive sarcomeres of a single muscle fiber were measured by gauging each width of the striation pattern, which was proved to be derived from striation structures of the single fiber by performing experiments using different polarization lights and different focus depths. At the resting state, each sarcomere length was identical at the fixed muscle length and in proportion to the length ranging over 91-123% of the natural length. Each sarcomere length was unchanged at the steady state during isometric tetanic contractions. Individual sarcomere lengths in the central part of the skeletal muscle were identical at resting and at isometric tetanic contractions even in the thick muscle fiber specimen.

Distribution of actin bundles in Bowman’s capsule of rat kidney

In this study we define the distribution of actin bundle arrangement in Bowman’s capsule of rat renal corpuscles. Parietal cells of Bowman’s capsule were examined by conventional light microscopy, electron microscopy and confocal microscopy. Within each parietal cell individual actin bundles are arranged in a parallel fashion running the length of the cell. Computer reconstructions obtained using confocal microscopy clearly show the lengths of actin bundles to be arranged, on a capsule level, end-to-end, at angles and perpendicular to bundles in adjacent cells. The bundles stain positively for non-muscle myosin and vinculin. The presence and arrangement of actin bundles in parietal cells is consistent with a role in reinforcing capsule structure.

Ultrafine fibers formed in electric fields

We describe the preparation of several materials in the form of free-standing ultrafine fibers. The materials are made by evaporating material in an inert gas in the presence of electric fields. Fiber diameters are typically 100–300 Å and irregular. Lengths of fibers or fiber bundles extend up to 10 cm. Materials range from transition metals, non-transition metals, semimetals and semiconductors. In most cases, they appear to be the smallest free-standing microwires of these lengths that have been made from these materials.