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Microvascular changes are considered key factors in the process of intervertebral disk degeneration (IDD). Microvascular invasion and growth into the nucleus pulposus (NP) and cartilaginous endplates are unfavorable factors that trigger IDD. In contrast, the rich distribution of microvessels in the bony endplates and outer layers of the annulus fibrosus is an important safeguard for the nutrient supply and metabolism of the intervertebral disk (IVD). In particular, the adequate supply of microvessels in the bony endplates is the main source of the nutritional supply for the entire IVD. Microvessels can affect the progression of IDD through a variety of pathways. Many studies have explored the effects of microvessel alterations in the NP, annulus fibrosus, cartilaginous endplates, and bony endplates on the local microenvironment through inflammation, apoptosis, and senescence. Studies also elucidated the important roles of microvessel alterations in the process of IDD, as well as conducted in‐depth explorations of cytokines and biologics that can inhibit or promote the ingrowth of microvessels. Therefore, the present manuscript reviews the published literature on the effects of microvascular changes on IVD to summarize the roles of microvessels in IVD and elaborate on the mechanisms of action that promote or inhibit de novo microvessel formation in IVD.

Microvascular changes are considered key factors in the process of intervertebral disk degeneration (IDD). Microvascular invasion and growth into the nucleus pulposus (NP) and cartilaginous endplates are unfavorable factors that trigger IDD. In contrast, the rich distribution of microvessels in the bony endplates and outer layers of the annulus fibrosus is an important safeguard for the nutrient supply and metabolism of the intervertebral disk (IVD). In particular, the adequate supply of microvessels in the bony endplates is the main source of the nutritional supply for the entire IVD. Microvessels can affect the progression of IDD through a variety of pathways. Many studies have explored the effects of microvessel alterations in the NP, annulus fibrosus, cartilaginous endplates, and bony endplates on the local microenvironment through inflammation, apoptosis, and senescence. Studies also elucidated the important roles of microvessel alterations in the process of IDD, as well as conducted in‐depth explorations of cytokines and biologics that can inhibit or promote the ingrowth of microvessels. Therefore, the present manuscript reviews the published literature on the effects of microvascular changes on IVD to summarize the roles of microvessels in IVD and elaborate on the mechanisms of action that promote or inhibit de novo microvessel formation in IVD. [ABSTRACT FROM AUTHOR]

In aerodynamic studies, endplates or wingtip devices play a crucial role in enhancing the performance of airfoil blades and minimizing losses. This is particularly important for wind turbines, especially the drag-type Savonius turbine. This paper aims to investigate the effects of different endplate designs. Both experimental works and numerical simulations were conducted on a Savonius rotor with an aspect ratio of 1. A total of eight different endplate geometries and sizes were investigated. The mechanical torque and rotational speed were measured experimentally under various loads with an incoming wind speed of 5.89 m/s. The coefficient of torque (C T) and coefficient of power (C P) were calculated in both the experiments and simulations. The simulation was first validated using data from the literature, and flow characteristics were then scrutinized. The results indicate that the endplates greatly impact the turbine performance, with improvements of up to 299.7 % compared to a turbine without endplates from the experiment. The endplates help prevent flow leakage near the blade edges. In addition to tip losses reducing turbine performance, aerodynamic parasitic drag also contributed to a decrease in C P for the full endplate. The relationship between the aerodynamic parasitic drag with TSR is also reported. By implementing a well-designed endplate, these adverse effects can be mitigated. [Display omitted] • Comparison of eight different endplate designs. • Experiment and CFD simulation of Savonius rotor performance. • Tip losses and parasitic drag affect the performance significantly. • Flow characteristics and pressure distribution are scrutinized. • Full circular endplate outstands other endplate geometries. [ABSTRACT FROM AUTHOR]

The Savonius rotor is one of the simple and cost-effective vertical axis drag type devices for hydropower generation. The main drawback of the Savonius hydrokinetic turbine is its low performance due to negative torque developed by returning blade profile. In this paper, the performance of modified V-shaped rotor blades with different V-angles ranging from 90° to 40°, by maintaining fixed edge length, arc radius and aspect ratio of 0.7 is investigated. The numerical analysis is carried out to estimate the optimum V-angle by maintaining 70 mm depth of water with an inlet velocity of 0.3090 m/s. The numerical study revealed that, for 80° V-angle rotor blade profile, the maximum coefficient of power was found to be 0.2279 at a tip speed ratio of 0.9. This optimum V-angle model was used for experimental analysis to study the effect of aspect ratio ranging from 0.7 to 1.75 using top, middle and bottom plates by maintaining 140 mm depth of water and inlet velocity of 0.513 m/s. The rotor blade with two endplates and one middle plate with an aspect ratio of 1.75 has shown a significant increase of performance by 86.13% at a tip speed ratio of 0.86 as compared to turbine blade with two endplates. • Novel rotor blade with varying V-angle ranging from 90° to 40° developed using CFD. • The negative torque developed by the returning blade is decreased. • The parametric experimental study is carried for Novel rotor blade. • The value of CPmax for optimum V blade with a V-angle of 80° is 0.4242. [ABSTRACT FROM AUTHOR]

As the energy demand is growing and fossil fuel based energy resources are getting depleted, there has been an increased focus on the use of renewable energy resources. Wind energy is a highly suitable energy resource that can be harvested for the purpose. This research deals with the design and fabrication of novel designs as a mean to harness wind energy using a ‘Savonius’ Turbine. It is generally employed to harvest the low to very low wind speed potentials. The paper introduces a novel concept about a Ducted Savonius wind turbine where power generation can increase more than 10 folds. The paper provides experimental validation of the effect of using a converging ducted structure with a single stage and double stage configurations of a Savonius wind turbine. The paper also compares the turbine’s performance with and without endplates and compares Single Stage and Double Stage Turbine. The experiment results show that around 15% increase in tangential blade velocity in single stage rotor when end plates are used. The results of the study proves that power coefficient increases with the addition of a converging ducted structure with the Savonius wind turbine, and also with the use of endplates.

Purpose: This study aimed at determining the variables that may prove useful in predicting clinical outcomes following lumbar disc arthroplasty. Methods: Pre- and post-operative imaging assessments were obtained for 99 single-level lumbar disc arthroplasty patients from a prospective IDE study. The assessments and patient demographics were tested to identify variables that were significantly associated with clinical outcomes. Results: Clinical outcome data were available for 85 % of patients at the 5-year follow-up. Numerous assessments made from the pre-operative imaging were found to have statistically significant associations with clinical outcomes at 2 and 5 years. The most notable factors were related to the amount of degeneration at the index level, with patients achieving better outcome scores at 5 years if they have higher grades of degeneration preoperatively. Conclusions: Several variables may prove effective at optimizing clinical outcomes including a preoperative disc height <8 mm, Modic type 2 changes adjacent to the target disc, a low amount of lordosis present at the treatment level, low levels of fatty replacement of the paraspinal musculature, a prominent amount of facet joint or disc degeneration, and the presence of flat or convex vertebral endplates. There were also post-operative findings associated with better patient outcomes including a larger percent of the endplate covered with the implant, larger implant heights, greater increases in disc space heights, and a larger increase in index level lumbar lordosis. These variables could be explored in other clinical studies to facilitate meta-analyses that could identify effective strategies to optimize clinical outcomes with lumbar disc arthroplasty. [ABSTRACT FROM AUTHOR]

The application of improved blade tip geometries is studied with the aim of identifying an effective design concept for industrial fan passive noise control. The concept developed optimizes a datum blade by means of profiled endplates at the tip, reducing fan noise by changing the tip leakage flow behaviour. Experimental and computational investigations have been carried out on a family of axial fans, in fully ducted configuration, to establish the aerodynamic merits of the proposed blade tip design concept. The flow mechanisms in the fan tip region are correlated to specific blade design features that promote a reduction of the fan aero-acoustic signature in both tonal and broadband noise components. The tip vortical flow structures are characterized, and their role in creation of overall stage acoustic emissions clarified. The reported research identifies modification of tip geometry as markedly affecting the multiple vortex behaviour of blade tip leakage flow by altering the near-wall fluid flow paths on both blade surfaces. Blade tip endplates were also demonstrated to influence the rotor loss behaviour in the blade tip region. Improvement of rotor efficiency was correlated to the control of tip leakage flows. [ABSTRACT FROM AUTHOR]

Abstract: The endplate is a crucial component in a proton exchange membrane fuel cell (PEMFC) stack. It can provide the necessary rigidity and strength for the stack. An aluminium alloy is one of the ideal materials for PEMFC endplates because of its low density and high rigidity. But it does not meet the requirements of corrosion resistance and electrical insulation in PEMFC environments. In this work, methods of sealing treatments and the conditions of aluminium alloy anodization were investigated. Corrosion resistances of the samples prepared by different technologies were evaluated in simulated PEMFC environments. The results showed that the corrosion resistance of the samples sealed by epoxy resin was greatly improved compared with those sealed in boiling water, and the samples anodized at a constant current density performed better than those anodized at a constant voltage. By insulation measurements, all of the samples showed good electrical insulation. The aluminium alloy endplate anodized at a constant current density and sealed with thermosetting bisphenol-A epoxy resin exhibited promising potential for practical applications by assembling it in a PEMFC stack and applying a life test. [Copyright &y& Elsevier]

This is a comparative in vitro biomechanical study of the primary stability of an anterior lumbar interbody stabilization. The objective was to compare the stability of a interbody stabilizing titanium cage with and without the retention of the bordering vertebral endplates, as well as to compare the titanium cage with a tricalcium phosphate block when the endplates are removed. An adequate blood supply is critical for interbody fusion, which suggests surgical treatment of the bordering endplates. On the other hand, primary stability is improved by the retention of the endplates. Furthermore, bone substitute materials are finding more frequent use due to complications associated with autologous bone grafts. Ten bovine lumbar spine motion segments (average age 6 months) were investigated. Pure bending loadings as well as eccentric axial compression loadings were applied. A titanium cage and tricalcium phosphate block, were tested in conjunction with an anterior augmentation (MACS). Range of motion, neutral zone (NZ) and bending stiffness were measured under pure bending to 10 Nm, and bending stiffness under axial loads of up to 1500 N. Range of motion of both implants in flexion-extension was significantly smaller than physiologic (cage without endplates 4.3°, cage with 2.8°, block without 3.4°, and physiologic 6.6°, all p<0.001). The cage with endplates and the block without endplates were both significantly stiffer than physiologic in all directions except left lateral bending. The block without endplates and the cage with endplates were both stiffer than the cage without endplates. The results suggest that the use of the bone substitute block provides better stability than the cage when the endplates are removed. [ABSTRACT FROM AUTHOR]

The magnet design, fabrication, and measurement of HIRFL-CSR (Heavy Ion Research Facility in Lanzhou Cooling Storage Ring) are presented. All magnets will be laminated and welded with an armor-coated surface between two big endplates made of sticking glue 0.5 mm-thick sheets. The dipole of CSRm was chosen an H type with an air circle on the pole to improve the field uniformity. The dipole of CSRe was chosen the C type with an air circle and two air slots on the pole to improve the field homogeneity. Its reproducibility of magnet to magnet was adjusted with inserting small laminating pieces before demountable pole ends to reach less than ±2 × 10-4 at optimized field level. CSRm quadrupoles diameter is 170 mm and has two different lengths, and its endplates were made with punching pieces after coating with epoxy glue, there is chamfered directly on the pole ends to reduce 12th-order contribution of field and without the demountable pole ends. CSRe main quadrupoles diameter is 240 mm and has two different lengths, and its endplates were also made with punching pieces coated with epoxy glue, there is also chamfered directly on the pole ends to reduce 12th-order contribution of field like CSRm. [ABSTRACT FROM AUTHOR]

Abstract: Posterior lumbar interbody fusion (PLIF) and anterior lumbar interbody fusion (ALIF) have become routine alternatives to intertransverse process fusion. The use of Coblation® (ArthroCare Corporation, Sunnyvale, CA) allows for routine and reproducible removal of cartilaginous endplate down to the bony endplate. Our experience with this new technology is reviewed. The authors used Coblation® to prepare endplates of 10 consecutive patients undergoing interbody fusion. The results were compared to the following 10 consecutive patients undergoing interbody fusion with endplates prepared in the standard fashion with curettes and rongeurs. The same interbody grafts and instrumentation were used in all patients. Follow-up X-rays were done at 1 week, 6 weeks, 6 months, 1 year, and then each year thereafter. The 20 patients were reviewed along with their films. In each patient the disk spaces and the ALIF/PLIF cages appeared to be fused by 6 months. There was one superficial wound infection in each group. In each of the cases in which PLIF was performed, the cages were augmented by posterior lateral graft and pedicle screw fixation. All patients in both groups reported improvement in pain and/or neurologic symptoms by 6 months. The patients were followed for 4.6 years in the Coblation® group and 4.1 years in the standard group. Disk space height was measured in all patients at 6 months. In the Coblation® group, average disk space height was 9.0 mm compared to 8.2 mm in the standard group (p <0.1). We feel that the maintenance of normal structures within the lumbar spine with anterior/posterior lumbar interbody fusions and non-mechanical means of preparing the endplates are advantageous. Clearly, the number of patients involved and the length of follow-up limit this study, but it serves as an early indicator that endplate preparation may play a role in graft subsidence and fusion rates. Additional study is warranted. [Copyright &y& Elsevier]

Using normality theory and a simplified beam model, a theoretical method is built up to evaluate the relationship between the central deflection of a corrugated panel and external uniformly distributed pressure load. The interaction between the bending moment and the membrane force in the panel is included, as well as the influence of connections. This theoretical model is calibrated against finite element analyses. The results show encouraging agreement. [ABSTRACT FROM AUTHOR]

The rabbit digastric muscle has a single belly that opens and retracts the mandible. It does not contain connective tissue partitions, and all fibers arise from the same tendon and insert into a single broad site. Historically, it was assumed that the muscle functioned as a single unit. Since we had preliminary evidence that this might not be the case, we carried out five small studies in rabbits. First, we showed that electromyographic (EMG) activity varies between recording sites within the muscle during the masticatory cycle induced by repetitive stimulation of the sensorimotor cortex. We found that EMG activity in the caudal region sometimes began before the anterior EMG during mastication when the jaw swung to the side of the muscle, but the two regions became active at the same time during other patterns. We next showed that separate branches of the mylohyoid nerve enter the anterior, intermediate and caudal regions of the digastric. However, a separate study showed that the motor endplates were distributed across a continuous sheet, consistent with a single anatomical partition. We then stimulated single nerve branches to deplete glycogen. By comparing the optical density of fibers labeled by the periodic acid-Schiff method for glycogen, we were able to show that the three branches innervate separate regions of the muscle. Finally, we applied either FluoroGold or Fast Blue dyes to the central cut ends of the branches to label the cell bodies of the three pools of motoneurons. These were found within the middle and caudal thirds of the trigeminal motor nucleus, but there appeared to be no spatial separation of the three pools or double labeling of cells. We conclude that the digastric muscle contains two and possibly three functional subregions. The fact that the motoneurons are intermingled suggests that the distribution of motor commands to the three pools is not based on their location.Copyright © 2002 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The white and red regions of the iliofibularis muscle of the lizard Dipsosaurus dorsalis were analyzed using histologic and morphometric analysis. These regions are composed of fast glycolytic (FG) and both fast oxidative, glycolytic (FOG) and tonic fibers, respectively. Endplate morphology and number of endplates per fiber were estimated from fibers from both areas. Capillary volume densities of the red and white regions were quantified from transverse sections. Mitochondrial volume of fibers from the red and white regions were estimated from electron micrographs. All fibers from the white region of the iliofibularis possessed a single, well defined endplate, as did most red region fibers. The remaining red fibers (28±5%) possessed an average of 14.7±3 endplates each, distributed along the entire length of the fiber at intervals of approximately 1124 μm. Red fibers possessed twice the mitochondrial volume of white fibers (7.6±0.4%, red; 3.8±0.3%, white). Mitochondria were distributed uniformly through the fibers from both regions. Capillary anisotropy was low ( γ = 1.018) in both regions. Capillary densities of the red region (629±35 mm) were much greater than those of the corresponding White region (73±8 mm). The data indicate that capillary densities, mitochondrial volumes and theoretical diffusion distances correlate well with the oxidative capacity of lizard muscle fibers. Tonic fibrs of this species appear oxidative and therefore metabolically capable of functioning during locomotion. The similar mitochondrial volumes and capillary densities of reptilian and mammalian muscles suggest that the greater oxidative capacity of mammalian muscle is due in part to possession of more oxidatively active mitochondria rather than to possession of more mitochondria per se. [ABSTRACT FROM AUTHOR]

The uptake of C-choline into the axonal part of the motor endplate and muscle of mouse diaphragms was investigated by autoradiography. With i. v. doses of 0.1 μg/g choline chloride, the uptake into the nerve endings is fast (<2 min) and into muscle slower (>2 min). With higher doses (1.0 μg/g) the uptake into muscle tissue is accelerated. The radioactivity in the endplates decreases with a halflife time of 20 min and remains constant in the muscle fibres over 60 min. Denervation by cutting the phrenic nerve reduces the uptake into endplates by 40% within 14 h, but probably induces uptake into regenerating Schwann cells during 30 days. Some compounds with choline-like structure (hemicholinium-3, decamethylen-dicholine, triethyl-choline) reduce the high-affinity uptake of choline into the nerve endings with sublethal doses, whereas tetraethylammonium and N-hydroxyethyl-4-(1-naphthylvinyl)-pyridinium, an inhibitor of cholinacetyltransferase, are less active. Half lethal doses of cocaine, imipramine and reserpine have no significant action on uptake of choline into the endplates. Chlorpromazine slightly diminishes the uptake into endplates. Chlorpromazine and imipramine reduce uptake into the muscle fibres. [ABSTRACT FROM AUTHOR]

Expandable intravertebral implants are self-expanding devices applied percutaneously by the posterior transpedicular approach. These devices introduce the concept of anatomical restoration of vertebral body endplates and direct anatomical reduction performed from the interior of the vertebral body with a compression fracture. This paper aims to provide a narrative review on the concept, indications, biomechanical characteristics, as well as functional and radiographic outcomes of the main expandable intravertebral implants currently available, in terms of their application to thoracolumbar spine traumatology. To this end, we performed a search in July 2021 on the MEDLINE/PubMed platform with the words "expandable intravertebral implant", "armed kyphoplasty", "Vertebral Body Stenting" or "stentoplasty" and "SpineJack". The search yielded 144 papers, and of those, we included 15 in this review. We concluded that percutaneous transpedicular posterior access, the ability to reduce vertebral body fractures, particularly of the vertebral endplates and to maintain the vertebral body height, makes the application of expandable intravertebral implants an attractive option in the treatment of thoracolumbar vertebral compression fractures. However, more prospective, randomized, and large-scale blinded studies are still warranted, especially comparative studies between treatments and about the preferential use of an expansive implant over others, in order to gain definitive insights into the effectiveness and indications of each of these devices., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Moura et al.)

Objective To radiologically measure the parameters of endplates and the apophyseal ring and to suggest an applicable length for a lumbar interbody cage for Chinese patients. Methods Twenty-four volunteers were enrolled to undergo lumbar computed tomography (CT). On the endplate plane, the diameters of the endplates (L1–S1) were measured along the axis of the cage with different lumbar interbody fusion procedures. Whereas the mid-oblique diameter (mid-OD) and maximum oblique diameter (max-OD) were defined as the minimal and maximal diameters of the endplates in transforaminal lumbar interbody fusion (TLIF), side-sagittal diameter (side-SD), mid-sagittal diameter (mid-SD), and transverse diameter (TD) represented the diameters of endplates in posterior lumbar interbody fusion (PLIF), anterior lumbar interbody fusion (ALIF); and oblique lateral interbody fusion (OLIF)/extreme lateral interbody fusion (XLIF), /direct lateral interbody fusion (DLIF), respectively. R1–R10 were the widths of the apophyseal ring covered by diameters at both ends. We used the proposed formula to calculate the cage length: 1) minimal length of TLIF cage = mid-OD − ½ (R1 + R2), 2) maximal length of TLIF cage = max-OD − ½ (R3 + R4), 3) length of PLIF cage = side-SD − ½ (R5 + R6), 4) length of OLIF/XLIF/DLIF cage = TD − ½ (R7 + R8), and 5) length of ALIF cage = mid-SD − ½ (R9 + R10). Results The lengths of the TLIF cage were more than 30 mm for men and 26 mm for women in L1/2–L4/5, with a large range in L5–S1. For PLIF, the lengths were 28 to 30 mm for men and 24 to 26 mm for women in L1/2–L4/5, with 26 mm and 22 mm, respectively, in L5–S1. For the OLIF/XLIF/DLIF cage, the lengths were 38 mm in L1/2 and 41 to 43 mm in L2/3–L4/5 for men and 35 mm in L1/2–L2/3 and 38 mm in L3/4–L4/5 for women. The ALIF cage lengths were 27 mm in L1/2 and L5–S1 and 29 mm in L2/3–L4/5 for men and 23 mm in L1/2 and L5–S1 and 25 mm in L2/3–L4/5 for women. Conclusions The choice of an appropriate length for a lumbar interbody cage should be based on the procedure and fusion level, which can match the endplates anatomically. The size of the lumbar interbody cage is affected by many factors, and a simple calculation may not be clinically relevant. [ABSTRACT FROM AUTHOR]