Bone scaffolds serve a crucial role in tissue engineering, particularly in facilitating bone regeneration where natural repair is insufficient. Despite advancements in the fabrication of polymeric bone scaffolds, the challenge remains to optimize their mechanical resilience. Specifically, research on the fatigue behaviour of polymeric bone scaffolds is scarce. This study investigates the influence of pore architecture on the mechanical performance of poly-lactic-acid (PLA) scaffolds under quasi-static and cyclic compression. PLA scaffolds with a 60% porosity were fabricated using extrusion-based 3D printing in various designs: Gyroid, Lidinoid, Fischer-Koch, IWP, and Voronoi. Results demonstrated that Gyroid scaffolds had the highest compressive strength (6.6 MPa), followed by Lidinoid, Fischer-Koch, IWP, and Voronoi designs. Increased strut thickness was linked to higher compressive strength. However, normalized fatigue resistance showed a different pattern. While scaffolds resisted fatigue cycles at low strain amplitudes, fatigue damage was observed at higher strains. Voronoi structures exhibited the highest normalized fatigue performance, enduring around 58,000 cycles at 85% strain amplitude, followed by Gyroid, Fischer-Koch, Lidinoid, and IWP structures. Enhanced fatigue performance in different topologies correlated with the minimum cross-sectional area of scaffolds. Given the importance of both static and fatigue strength, the Gyroid topology emerges as the superior choice overall.

Treatment strategies for hard tissue defects aim to establish a mineralized microenvironment that facilitates tissue remodeling. As a mineralized tissue, cementum shares a similar structure with bone and exhibits an excellent capacity to resist resorption under compression. Macrophages are crucial for mineralized remodeling; however, their functional alterations in the microenvironment of cementum remain poorly understood. Therefore, this study explores the mechanisms by which cementum resists resorption under compression and the regulatory roles of cementoblasts in macrophage functions. As a result, extracellular vesicles from compression-loaded cementoblasts (Comp-EVs) promote macrophage M2 polarization and enhance the clearance of apoptotic cells (efferocytosis) by 2- to 3-fold. Local injection of Comp-EVs relieves cementum destruction in mouse root resorption model by activating the tissue repair function of macrophages. Moreover, Comp-EV-loaded hydrogels achieve significant bone healing in calvarial bone defect. Unexpectedly, under compression, EV secretion in cementoblasts is reduced by half. RNA-Seq analysis and verification reveal that Rab35 expression decreases by 60% under compression, thereby hampering the release of EVs. Rab35 overexpression is proposed as a modification of cementoblasts to boost the yield of Comp-EVs. Collectively, Comp-EVs activate the repair function of macrophages, which will be a potential therapeutic strategy for hard tissue repair and regeneration.

UNASSIGNED: Left subclavian artery (LSA) preservation during thoracic endovascular aortic repair (TEVAR) has been related to low morbidity. This study investigated the incidence of LSA stent compression in patients managed with fenestrated endovascular arch repair (f-Arch) and evaluated the impact of anatomic and technical factors on LSA stent outcomes.
UNASSIGNED: A single-center retrospective analysis of patients managed with single-fenestration devices (Cook Medical, Bloomington, IN, USA) for LSA preservation, between January 1, 2012 and November 30, 2023, was conducted. Anatomic (arch type, bovine arch, distance between the LSA and most proximal bone structure, left common carotid artery and aortic lesion, take-off angle, diameter, thrombus, calcification, dissection, tortuosity) and technical parameters (stent type, diameter, length, relining, post-dilation) were evaluated. Stent compression was any ≥50% stenosis (using center luminal line) of the stent compared with its initial diameter. Clinical outcomes included stroke and upper limb ischemia at 30 days and follow-up. Technical outcomes included stent compression and need for reintervention.
UNASSIGNED: Fifty-four cases were included. Only balloon-expandable covered stents were used, and relining during the index procedure was performed in 18%. No stroke or arm ischemia was recorded. One stent compression was detected at 30 days. During follow-up, no stroke or arm ischemia was diagnosed. Nine cases (18%) presented stent compression, with a mean time of stent-compression diagnosis at 18 months (interquartile range [IQR]=37, range=1-58 months) after the index procedure. Five (56%) underwent secondary relining. Follow-up after reintervention was uneventful. Lower distance to the nearest bone structure (compression group [CG]: 11.7±8.9 mm vs non-compression group [NCG]: 23.0±7.8 mm, p=0.003) and higher tortuosity index (CG: 1.3±0.4 vs NCG: 1.2±0.1, p=0.03) were associated with LSA stent compression.
UNASSIGNED: LSA stent compression in patients managed with f-Arch affected 1 in 5 cases, without clinical consequences. Distance to the nearest bone structure and higher tortuosity were associated with LSA stent compression.
CONCLUSIONS: Fenestrated endovascular arch repair for the preservation of the left subclavian artery (LSA) in patients needing landing within the aortic arch has been performed with encouraging outcomes. This analysis showed that LSA stent compression is met in 18% of patients, without though any clinical consequence. Pre-operative anatomic parameters, as lower distance to the nearest bone structure and higher tortuosity index affect negatively LSA stent performance while stent parameters seem to have no impact.

The development of multi-material filaments has enabled fused filament fabrication-based additive manufacturing to address demand for high-performance lightweight multifunctional components. In this study, polylactic acid (PLA) and acrylonitrile butadiene styrene based filaments with metallic reinforcements of magnetic iron (MI), stainless steel (SS), bronze (Br), copper (Cu), Bismuth (Bi), and Tungsten (W) were investigated to elucidate their complex processing-structure-property relationships. The microstructure of 3D-printed materials were characterized by microscopy and analyzed to determine the metal cross-sectional area percentage and the relationship between metal reinforcement, the polymer matrix, and porosity. Compression testing was conducted in directions parallel and perpendicular to the build direction in order to evaluate the effect of orientation and metal reinforcement on the mechanical properties. 3D-printed specimens experienced either fracture through print layers or layer-wise interfacial rupture for loads applied perpendicular and parallel to the print layers, respectively. A dependence of yield strength on loading orientation was observed for Br-PLA, Cu-PLA, SS-PLA, Bi-ABS, and W-ABS; however, MI-PLA and pure ABS specimens did not exhibit this sensitivity. Metal reinforcement also influenced the magnitude of compressive yield strength, with MI-PLA and SS-PLA demonstrating increased strength over Br-PLA and Cu-PLA, while ABS demonstrated increased strength over Bi-ABS and W-ABS. These results demonstrate the importance of considering orientation in printing and applications, the trade-off between various metallic reinforcements for added multifunctionality, and the potential of these tailored polymer composites for novel 3D-printed structures.

We evaluated the effect of compression leggings with micromassage in association with physical activity on women with lipedema, not previously treated and without recent changes in body weight. The treatment resulted in an improvement in all subjective parameters, in spontaneous and evoked pain, in the volume of the limbs, in the absence of significant changes in body weight, and regardless of the duration of use, age, years of illness, the clinical stage, and body mass index (BMI). Evoked pain did not improve in areas affected by untreated lipedema; foot circumferences did not increase. We found a significant reduction in the thickness of subcutaneous adipose tissue (SAT) and skin evaluated in multiple points of the lower limb. Micromassage compression leggings are proposed as an integral part of conservative treatment. A method is proposed for the clinical evaluation of evoked pain, called the Progressive Pain Check (PPC), which allows for the calculation of a numerical score called the Ricolfi-Patton Score (RPS) and for the ultrasound evaluation of tissues. The method is simple and repeatable and allows for completion of the clinical evaluation of the patient at diagnosis and for an evaluation of the effects of various treatments, even applied to just one side of the body.

BACKGROUND: Currently, low-level evidence suggests loss of ambulation associated with acute thoracolumbar disk extrusion is best treated by decompressive spinal surgery. Conservative management can be successful, but the proportion of dogs that recover and the fate of herniated material are uncertain.
OBJECTIVE: Determine the proportion of nonambulatory dogs with conservatively treated acute thoracolumbar disk extrusion that recover ambulation and measure the change in spinal cord compression during the first 12 weeks after presentation.
METHODS: Seventy-two client-owned nonambulatory dogs with acute thoracolumbar intervertebral disk extrusion.
METHODS: This is a prospective cohort study. Enrolled dogs underwent magnetic resonance imaging at presentation and owners were provided with conservative management recommendations. Imaging was repeated after 12 weeks. Recovery of ambulation was defined as 10 consecutive steps without falling. Spinal cord compression was determined from the cross-sectional area of the vertebral canal and extradural compressive material at the lesion epicenter. The association between recovery and change in compression over the 12-week observational period was examined.
RESULTS: Forty-nine of fifty-one (96%; 95% confidence interval [CI], 87%-99%) of deep pain-positive and 10/21 (48%; 95% CI, 28%-68%) of deep pain-negative dogs recovered ambulation within the 12-week period. The median time to ambulation was 11 and 25 days for deep pain-positive and -negative dogs, respectively. Reduction in spinal cord compression varied among individuals from minimal to complete and apparently was unrelated to the recovery of ambulation.
CONCLUSIONS: A high proportion of conservatively treated dogs recovered ambulation after conservative management of acute thoracolumbar disk herniation. Recovery was not dependent on the resolution of compression.

OBJECTIVE: To quantify dynamic gutter phenomena and endograft deformations during double chimney thoracic endovascular aortic repair (ch-TEVAR) in a physiological model of the thoracic aorta subjected to pulsatile haemodynamic conditions.
METHODS: Two in vitro procedures revascularizing the brachiocephalic trunk and left common carotid artery were performed representing both balloon-expandable (BE, Ankura-BeGraft) and self-expandable (SE, Ankura-Viabahn) double ch-TEVAR configurations. Retrospectively gated computed tomography (CT) was used to evaluate endograft behaviour. Device interactions were characterised according to gutter volume, gutter surface deviation, and endograft deformation (D-ratio) at end-diastolic and peak-systolic aortic pressure.
RESULTS: Use of BE chimney grafts resulted in three times total gutter volume compared to SE chimney grafts. Gutter volumes were observed to vary dynamically between the end-diastolic and peak-systolic phases of the cardiac cycle, with the most substantial change associated with the BE configuration. Chimney graft deformations were dependent on device type, with SE devices exhibiting up to twice the deformation as BE devices. When adjacent, SE chimney grafts were observed to support each other, and thus tended towards a more consistently circular shape.
CONCLUSIONS: Gutter and chimney graft behaviour were dependent on device type, and exhibited both spatial and temporal variability. This study emphasises notable differences between BE and SE double ch-TEVAR configurations which should be considered when evaluating risk of endoleak. The findings reported here also support the use of gated CT to better identify device-related complications with ch-TEVAR, and can be used in the design of next generation devices.

Dewatering is a critical step in cassava flours processing. Compression dewatering kinetics are useful to understand and design a dewatering operation. The dataset presents dewatering kinetics measured in a filtration-consolidation cell at constant pressure between 4 and 21 bar, on several cassava mashes (three batches fragmented at two particle size distributions (PSDs)). The dataset comprises, for each dewatering kinetic measurement, filtrate mass, cake height, data to estimate the pressure applied on the product (i.e. air pressure, compression force) as a function of time; and the moisture content measurements of the fresh and dewatered cassava and of the filtrate. A commented python script is included to read the dewatering experimental files and plot the kinetics Furthermore, the dataset extends its utility by including particle size distributions (PSDs) obtained from six cassava batches, subjected to several protocol variants. These data are useful for understanding the phenomena involved in cassava dewatering. They also serve as a valuable resource for researchers, designers, and operators to design cassava dewatering.

A point cloud is a representation of objects or scenes utilising unordered points comprising 3D positions and attributes. The ability of point clouds to mimic natural forms has gained significant attention from diverse applied fields, such as virtual reality and augmented reality. However, the point cloud, especially those representing dynamic scenes or objects in motion, must be compressed efficiently due to its huge data volume. The latest video-based point cloud compression (V-PCC) standard for dynamic point clouds divides the 3D point cloud into many patches using computationally expensive normal estimation, segmentation, and refinement. The patches are projected onto a 2D plane to apply existing video coding techniques. This process often results in losing proximity information and some original points. This loss induces artefacts that adversely affect user perception. The proposed method segments dynamic point clouds based on shape similarity and occlusion before patch generation. This segmentation strategy helps maintain the points\' proximity and retain more original points by exploiting the density and occlusion of the points. The experimental results establish that the proposed method significantly outperforms the V-PCC standard and other relevant methods regarding rate-distortion performance and subjective quality testing for both geometric and texture data of several benchmark video sequences.

As higher spatiotemporal resolution tactile sensing systems are being developed for prosthetics, wearables, and other biomedical applications, they demand faster sampling rates and generate larger data streams. Sparsifying transformations can alleviate these requirements by enabling compressive sampling and efficient data storage through compression. However, research on the best sparsifying transforms for tactile interactions is lagging. In this work we construct a library of orthogonal and biorthogonal wavelet transforms as sparsifying transforms for tactile interactions and compare their tradeoffs in compression and sparsity. We tested the sparsifying transforms on a publicly available high-density tactile object grasping dataset (548 sensor tactile glove, grasping 26 objects). In addition, we investigated which dimension wavelet transform-1D, 2D, or 3D-would best compress these tactile interactions. Our results show that wavelet transforms are highly efficient at compressing tactile data and can lead to very sparse and compact tactile representations. Additionally, our results show that 1D transforms achieve the sparsest representations, followed by 3D, and lastly 2D. Overall, the best wavelet for coarse approximation is Symlets 4 evaluated temporally which can sparsify to 0.5% sparsity and compress 10-bit tactile data to an average of 0.04 bits per pixel. Future studies can leverage the results of this paper to assist in the compressive sampling of large tactile arrays and free up computational resources for real-time processing on computationally constrained mobile platforms like neuroprosthetics.