Architecture Properties Research Articles

Stimuli‐Responsive Functional Polymeric Materials: Recent Advances and Future Perspectives

AbstractInspired by the extreme structural complexity and functional efficiency of biomolecules, researchers have developed stimuli‐responsive materials, capable of adapting their structural conformations and physicochemical properties upon external changes in temperature, pH, light, etc. These materials can expand, contract, or bend in response to external stimuli, which makes them useful for a variety of applications such as biomedicine, sensors, shape‐memory devices, and smart interface materials. Multistimuli‐responsive materials exhibit enhanced features than single‐/dual‐responsive materials, affording enhanced fine tuning of their parameters. Among such materials, reversibly cross‐linked networks have generated increasing interest recently due to their 3D architecture and unique properties, based on the low viscosity, good solubility, and high functionality of the building blocks, which can be further modified. In order to achieve dynamic self‐assembly, future research on stimuli‐responsive macromolecular self‐assembly should mimic thec structures, functions, and processes found in nature.

Local characterization of collagen architecture and mechanical properties of tissue engineered atherosclerotic plaque cap analogs.

Many cardiovascular events are triggered by fibrous cap rupture of an atherosclerotic plaque in arteries. However, cap rupture, including the impact of the cap's structural components, is poorly understood. To obtain better mechanistic insights in a biologically and mechanically controlled environment, we previously developed a tissue-engineered fibrous cap model. In the current study, we characterized the (local) structural and mechanical properties of these tissue-engineered cap analogs. Twenty-four collagenous cap analogs were cultured. The analogs were imaged with multiphoton microscopy with second-harmonic generation to obtain local collagen fiber orientation and dispersion. Then, the analogs were mechanically tested under uniaxial tensile loading until failure, and the local deformation (strain) and failure characteristics were analyzed. Our results demonstrated that the tissue-engineered analogs mimic the dominant (circumferential) fiber direction of human plaques. The analogs also exhibited a physiological strain stiffening response, similar to human fibrous plaque caps. Ruptures in the analogs initiated in and propagated towards local high-strain regions. The local strain values at the rupture sites were similar to the ones reported for carotid human fibrous plaque tissue. Finally, the study revealed that the rupture propagation path in the analogs followed the local fiber direction. STATEMENT OF SIGNIFICANCE: Many cardiovascular events are triggered by mechanical rupture of atherosclerotic plaque caps. Yet, cap rupture mechanics is poorly understood. This is mainly due to the scarcity of plaques for high-throughput testing and the structural complexity of plaques. To overcome this, we previously developed tissue-engineered cap analogs. The current study characterizes (local) structural and mechanical properties of these cap analogs. Our findings show that: (1) cap analogs closely mimic human fibrous caps, including fiber orientation and strain stiffening responses; (2) structural and mechanical properties of cap analogs are associated, which provides critical information for understanding plaque rupture; and (3) cap ruptures commonly start in and propagate towards high-strain areas, indicating the potential use of strain measurements for cap rupture risk assessment.

The Dynamics, Degradation, and Afterlives of Pectins: Influences on Cell Wall Assembly and Structure, Plant Development and Physiology, Agronomy, and Biotechnology.

Pectins underpin the assembly, molecular architecture, and physical properties of plant cell walls and through their effects on cell growth and adhesion influence many aspects of plant development. They are some of the most dynamic components of plant cell walls, and pectin remodeling and degradation by pectin-modifying enzymes can drive developmental programming via physical effects on the cell wall and the generation of oligosaccharides that can act as signaling ligands. Here, we introduce pectin structure and synthesis and discuss pectin functions in plants. We highlight recent advances in understanding the structure-function relationships of pectin-modifying enzymes and their products and how these advances point toward new approaches to bridging key knowledge gaps and manipulating pectin dynamics to control plant development. Finally, we discuss how a deeper understanding of pectin dynamics might enable innovations in agronomy and biotechnology, unlocking new benefits from these ubiquitous but complex polysaccharides.

Enhancing structural health monitoring of fiber-reinforced polymer composites using piezoresistive Ti3C2Tx MXene fibers

The anisotropic behavior of fiber-reinforced polymer composites, coupled with their susceptibility to various failure modes, poses challenges for their structural health monitoring (SHM) during service life. To address this, non-destructive testing techniques have been employed, but they often suffer from drawbacks such as high costs and suboptimal resolutions. Moreover, routine inspections fail to disclose incidents or failures occurring between successive assessments. As a result, there is a growing emphasis on SHM methods that enable continuous monitoring without grounding the aircraft. Our research focuses on advancing aerospace SHM through the utilization of piezoresistive MXene fibers. MXene, characterized by its 2D nanofiber architecture and exceptional properties, offers unique advantages for strain sensing applications. We successfully fabricate piezoresistive MXene fibers using wet spinning and integrate them into carbon fiber-reinforced epoxy laminates for in-situ strain sensing. Unlike previous studies focused on high strain levels, we adjust the strain levels to be comparable to those encountered in practical aerospace applications. Our results demonstrate remarkable sensitivity of MXene fibers within low strain ranges, with a maximum sensitivity of 0.9 at 0.13% strain. Additionally, MXene fibers exhibited high reliability for repetitive tensile deformations and low-velocity impact loading scenarios. This research contributes to the development of self-sensing composites, offering enhanced capabilities for early detection of damage and defects in aerospace structures, thereby improving safety and reducing maintenance expenses.

Porosity Tunable Metal-Organic Framework (MOF)-Based Composites for Energy Storage Applications: Recent Progress.

To solve the energy crisis and environmental issues, it is essential to create effective and sustainable energy conversion and storage technologies. Traditional materials for energy conversion and storage however have several drawbacks, such as poor energy density and inadequate efficiency. The advantages of MOF-based materials, such as pristine MOFs, also known as porous coordination polymers, MOF composites, and their derivatives, over traditional materials, have been thoroughly investigated. These advantages stem from their high specific surface area, highly adjustable structure, and multifunctional nature. MOFs are promising porous materials for energy storage and conversion technologies, according to research on their many applications. Moreover, MOFs have served as sacrificial materials for the synthesis of different nanostructures for energy applications and as support substrates for metals, metal oxides, semiconductors, and complexes. One of the most intriguing characteristics of MOFs is their porosity, which permits space on the micro- and meso-scales, revealing and limiting their functions. The main goals of MOF research are to create high-porosity MOFs and develop more efficient activation techniques to preserve and access their pore space. This paper examines the porosity tunable mixed and hybrid MOF, pore architecture, physical and chemical properties of tunable MOF, pore conditions, market size of MOF, and the latest development of MOFs as precursors for the synthesis of different nanostructures and their potential uses.

Sex-Related Differences in Motor Unit Firing Rate and Pennation Angle.

Motor unit firing rate (MUFR) and pennation angle were measured concurrently in males and females from submaximal to maximal intensities. Thirty participants, (16F and 14M) performed isometric dorsiflexion contractions at 20%, 40%, 60%, 80% and 100% of maximal voluntary contraction (MVC). During each contraction, measures of MUFR were obtained via surface electromyography decomposition, and muscle fiber pennation angle and fascicle length were obtained via ultrasound. There was no significant interaction effect of sex and contraction intensity present for mean MUFR (p=0.24), pennation angle (p=0.98), or fascicle length (p=0.81). Males had greater mean MUFR (p<0.001), pennation angle (p=0.02), and fascicle length (p=0.03) compared to females. In general, mean MUFR (p<0.001) and pennation angle (p<0.02), increased with increasing contraction intensity, however, fascicle length (p=0.30) was similar across contraction intensities. There were no significant relationships between mean MUFR and pennation angle for males (r=0.18, p=0.13) or females (r=0.20, p=0.09), nor between mean MUFR and fascicle length for males (r=0.20, p=0.10) or females (r=0.21, p=0.07). Although sex-related differences in MUFR, pennation angle and fascicle length were present, there were no relationships between MUFR and the muscle properties. These results suggest that sex-related differences in mean MUFR may not be associated with the sex-related differences in the muscle architectural properties currently investigated.

Fabrication and applications of biofunctional collagen biomaterials in tissue engineering.

Collagen is extensively used in tissue engineering for various organ tissue regeneration due to the main component of human organ extracellular matrix (ECM) and their inherent nature bioactivity. Collagen various types naturally exist in different organ ECMs. Collagen fabricated with natural ECM mimics architecture, composition and mechanical properties for various organ tissue regeneration. Collagen fabrication with organ-specific biofunctionality facilitated organ tissue engineering as compared to unmodified collagen biomaterials. Collagen biofunctionality improved by subjecting collagen to synthesis, fibers and surface modifications, and blending with other components. Furthermore, collagen is loaded with bioactive molecules, growth factors, drugs and cells also enhancing the biofunctionality of collagen biomaterials. In this review, we will explore the recent advancements in biofunctional collagen biomaterials fabrication with organ-specific biofunctionality in tissue engineering to resolve various organ tissue engineering issues and regeneration challenges. Biofunctional collagen biomaterials stimulate microenvironments inside and around the implants to excellently regulate cellular activities, differentiate cells into organ native cells, enhanced ECM production and remodeling to regenerate organ tissues with native structure, function and maturation. This review critically explored biofunctional collagen biomaterials fabrication in resolving various organ tissue engineering issues and regeneration challenges, and opening new directions of biofunctional collagen biomaterials fabrication, design and applications.

Study on the mechanical properties of Ti-6Al-4V alloy with minimal surface structures: effects of different heat treatment temperatures

Abstract Triply periodic minimal surface (TPMS) structures are widely used in scaffold design for biomaterials due to their excellent porous architecture and mechanical properties. This study utilized selective laser melting (SLM) to fabricate TPMS scaffold models with porosities of 50%, 60%, 70%, and 80%, based on Gyroid and Primitive unit cells. Compression tests were conducted to investigate the changes in mechanical properties of TPMS scaffolds before and after heat treatment. The mechanisms underlying these changes were elucidated through fracture morphology analysis, microstructural observation, and finite element simulation. Results indicate that Gyroid porous scaffolds exhibit superior compressive performance compared to Primitive scaffolds, with yield strength inversely related to porosity—lower porosity corresponds to higher yield strength. During compression, Primitive scaffolds exhibited a layer-by-layer stacking failure mode, whereas Gyroid scaffolds displayed a 45° shear failure mode. The Gyroid porous scaffolds showed uniform and continuous stress distribution, and heat treatment effectively relieved residual stresses, enhancing yield strength and toughness. In contrast, Primitive porous scaffolds demonstrated stress concentration regions that reach yield limits under compression, leading to fracture. Heat treatment did not alleviate these stress concentrations but instead reduced the material’s yield limit, accelerating scaffold failure.

Automated Rooftop Solar Panel Detection Through Convolutional Neural Networks

Transforming the global energy sector from fossil-fuel based to renewable energy sources is crucial to limiting global warming and achieving climate neutrality. The decentralized nature of the renewable energy system allows private households to deploy photovoltaic systems on their rooftops. However, inconsistent data on installed photovoltaic (PV) systems complicate planning for an efficient grid expansion. To address this issue, deep-learning techniques, can support collecting data about PV systems from aerial and satellite imagery. Previous research, however, lacks the consideration for ground truth data-specific characteristics of PV panels. This study aims to implement a semantic segmentation model that detects PV systems in aerial imagery to explore the impact of area-specific characteristics in the training data and CNN hyperparameters on the performance of a CNN. Hence, a U-Net architecture is employed to analyze land use types, rooftop colors, and lower-resolution images. Additionally, the impact of near-infrared data on the detection rate of PV panels is analyzed. The results indicate that a U-Net is suitable for classifying PV panels in high-resolution aerial imagery (10 cm) by reaching F1 scores of up to 91.75% while demonstrating the importance of adapting the training data to area-specific ground truth data concerning urban and architectural properties.

Unlocking the Heterogeneity in Acute Leukaemia: Dissection of Clonal Architecture and Metabolic Properties for Clinical Interventions.

Genetic studies of haematological cancers have pointed out the heterogeneity of leukaemia in its different subpopulations, with distinct mutations and characteristics, impacting the treatment response. Next-generation sequencing (NGS) and genome-wide analyses, as well as single-cell technologies, have offered unprecedented insights into the clonal heterogeneity within the same tumour. A key component of this heterogeneity that remains unexplored is the intracellular metabolome, a dynamic network that determines cell functions, signalling, epigenome regulation, immunity and inflammation. Understanding the metabolic diversities among cancer cells and their surrounding environments is therefore essential in unravelling the complexities of leukaemia and improving therapeutic strategies. Here, we describe the currently available methodologies and approaches to addressing the dynamic heterogeneity of leukaemia progression. In the second section, we focus on metabolic leukaemic vulnerabilities in acute myeloid leukaemia (AML) and acute lymphoblastic leukaemia (ALL). Lastly, we provide a comprehensive overview of the most interesting clinical trials designed to target these metabolic dependencies, highlighting their potential to advance therapeutic strategies in leukaemia treatment. The integration of multi-omics data for cancer identification with the metabolic states of tumour cells will enable a comprehensive "micro-to-macro" approach for the refinement of clinical practices and delivery of personalised therapies.

Ankyrin-B is required for the establishment and maintenance of lens cytoarchitecture, mechanics and clarity.

The transparent ocular lens is essential for vision because it focuses light onto the retina. Despite recognition of the importance of its unique cellular architecture and mechanical properties, the molecular mechanisms governing these attributes remain elusive. This study aims to elucidate the role of ankyrin-B (AnkB, encoded by ANK2), a membrane scaffolding protein, in lens cytoarchitecture, growth and function using a conditional knockout (cKO) mouse model. The AnkB cKO mouse has no defects in lens morphogenesis but exhibited changes that supported a global role for AnkB in maintenance of lens clarity, size, cytoarchitecture, membrane organization and stiffness. Notably, absence of AnkB led to nuclear cataract formation, which was evident from postnatal day 16. AnkB cKO lens fibers exhibit progressive disruption in membrane organization of the spectrin-actin cytoskeleton, cell adhesion proteins and channel proteins; loss and degradation of several membrane proteins [such as NrCAM. N-cadherin (CDH2) and aquaporin-0 (also known as MIP)]; along with a disorganized plasma membrane and impaired membrane interdigitations. Furthermore, absence of AnkB led to decreased lens stiffness. Collectively, these results illustrate the essential role for AnkB in lens architecture, growth and function through its involvement in membrane skeletal and protein organization and stability.

Nutrient availability influences E. coli biofilm properties and the structure of purified curli amyloid fibers

Bacterial biofilms are highly adaptable and resilient to challenges. Nutrient availability can induce changes in biofilm growth, architecture and mechanical properties. Their extracellular matrix plays an important role in achieving biofilm stability under different environmental conditions. Curli amyloid fibers are critical for the architecture and stiffness of E. coli biofilms, but how this major matrix component adapts to different environmental cues remains unclear. We investigated, for the first time, the effect of nutrient availability both on biofilm material properties and on the structure and properties of curli amyloid fibers extracted from similar biofilms. Our results show that biofilms grown on low nutrient substrates are stiffer, contain more curli fibers, and these fibers present higher β-sheet content and chemical stability. Our multiscale study sheds new light on the relationship between bacterial matrix molecular structure and biofilm macroscopic properties. This knowledge will benefit the development of both anti-biofilm strategies and biofilm-based materials.

Defining the extracellular matrix in non-cartilage soft-tissues in osteoarthritis: a systematic review.

Extracellular matrix (ECM) is a critical determinant of tissue mechanobiology, yet remains poorly characterized in joint tissues beyond cartilage in osteoarthritis (OA). This review aimed to define the composition and architecture of non-cartilage soft joint tissue structural ECM in human OA, and to compare the changes observed in humans with those seen in animal models of the disease. A systematic search strategy, devised using relevant matrix, tissue, and disease nomenclature, was run through the MEDLINE, Embase, and Scopus databases. Demographic, clinical, and biological data were extracted from eligible studies. Bias analysis was performed. A total of 161 studies were included, which covered capsule, ligaments, meniscus, skeletal muscle, synovium, and tendon in both humans and animals, and fat pad and intervertebral disc in humans only. These studies covered a wide variety of ECM features, including individual ECM components (i.e. collagens, proteoglycans, and glycoproteins), ECM architecture (i.e. collagen fibre organization and diameter), and viscoelastic properties (i.e. elastic and compressive modulus). Some ECM changes, notably calcification and the loss of collagen fibre organization, have been extensively studied across osteoarthritic tissues. However, most ECM features were only studied by one or a few papers in each tissue. When comparisons were possible, the results from animal experiments largely concurred with those from human studies, although some findings were contradictory. Changes in ECM composition and architecture occur throughout non-cartilage soft tissues in the osteoarthritic joint, but most of these remain poorly defined due to the low number of studies and lack of healthy comparator groups.

Mask2Anomaly: Mask Transformer for Universal Open-Set Segmentation.

Segmenting unknown or anomalous object instances is a critical task in autonomous driving applications, and it is approached traditionally as a per-pixel classification problem. However, reasoning individually about each pixel without considering their contextual semantics results in high uncertainty around the objects' boundaries and numerous false positives. We propose a paradigm change by shifting from a per-pixel classification to a mask classification. Our mask-based method, Mask2Anomaly, demonstrates the feasibility of integrating a mask-classification architecture to jointly address anomaly segmentation, open-set semantic segmentation, and open-set panoptic segmentation. Mask2Anomaly includes several technical novelties that are designed to improve the detection of anomalies/unknown objects: i) a global masked attention module to focus individually on the foreground and background regions; ii) a mask contrastive learning that maximizes the margin between an anomaly and known classes; iii) a mask refinement solution to reduce false positives; and iv) a novel approach to mine unknown instances based on the mask- architecture properties. By comprehensive qualitative and qualitative evaluation, we show Mask2Anomaly achieves new state-of-the-art results across the benchmarks of anomaly segmentation, open-set semantic segmentation, and open-set panoptic segmentation.

Mechanism and Applications of Biochar Carbon Dots and Nanocomposites in Heavy Metal Ion Sensing and Adsorption

Biochar is a carbonaceous material produced by the pyrolysis of biomass. Biochar has been embraced due to its various properties as well as its broad utility in soil and water pollution. Biochar technology is the answer to all the numerous problems concerning the environment. There has also been a lot of interest in biochar nanotechnology because of the improvements, especially in the physical, chemical, and surface characteristics of biochar. The biochar is further transformable into a number of forms of nanomaterials too, such as carbon dots (CDs) and nanocomposites. The modification of the biochar affects the mechanisms in the adsorption of pollutants from wastewater. CDs attract attention because of their unique properties, such as optical, biological, surface, and solubility properties among others. Due to their unique architecture and interesting properties, numerous disciplines have shown considerable interest in them. CDs are suitable as fluorescence probes. The fluorescence of CDs was reduced by all metal ions but to different extents. From the current review, we derive some relevant information on biochar and biochar nanotechnology and the factors that determine its properties and its mechanism in metal sensing and adsorption. . KEYWORDS :Biochar nanocomposites, Carbon dot, Fluorescence probes, Heavy metal, Sustainability

Optimized uniform sampling and validation of fiber tracts from magnetic resonance tractography for in vivo architectural measurement of human forearm muscles.

In vivo muscle architectural parameters can be calculated from the fiber tracts using magnetic resonance (MR) tractography. However, the reconstructed tracts may be unevenly distributed within the muscle volume and there lacks commonly used metric to quantitatively evaluate the validity of the tracts. Our objective is to measure forearm muscle architecture by uniformly sampling fiber tracts from the candidate streamlines in MR tractography and validate the reconstructed fiber tracts qualitatively and quantitatively. We proposed farthest streamline sampling (FSS) to uniformly sample fiber tracts from the candidate streamlines. The method was evaluated on the MR data acquired from 12 healthy subjects for 17 forearm muscles and was compared with two conventional methods through uniform coverage performance. Anatomical correctness was verified by: 1. visually assessing fiber orientation, 2. checking whether architectural parameters were within physiological ranges and 3. classifying architectural types. The proposed FSS yielded optimal uniform coverage performance among the three methods (P<0.05). FSS reduced the sampling of long tracts (10% fiber length reduction, P<0.05), and the estimated architectural parameters were within the physiological ranges (P<0.05). The tractography visually matched cadaveric specimens. The architectural types of 16 muscles were correctly classified except for the palmaris longus, which exhibited a linear arrangement of fiber endpoints (R2 = 0.95±0.02, P<0.001). The proposed FSS method reconstructed uniformly distributed fiber tracts and the anatomical correctness of the reconstructed tracts was verified. The novel methods allow for accurate in vivo muscle architectural measurement, which was demonstrated through the characterization of architectural properties in human forearm muscles.

Structural and Thermal Characterization of Bluepha® Biopolyesters: Insights into Molecular Architecture and Potential Applications.

This study presents an in-depth molecular and structural characterization of novel biopolyesters developed under the trademark Bluepha®. The primary aim was to elucidate the relationship between chemical structure, chain architecture, and material properties of these biopolyesters to define their potential applications across various sectors. Proton nuclear magnetic resonance (1H NMR) analysis identified the biopolyesters as poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] (PHBH) copolymers, containing 4% and 10% molar content of hydroxyhexanoate (HH) units, respectively. Mass spectrometry analysis of PHBH oligomers, produced via controlled thermal degradation, further confirmed the chemical structure and molecular architecture of the PHBH samples. Additionally, multistage electrospray ionization mass spectrometry (ESI-MS/MS) provided insights into the chemical homogeneity and arrangement of comonomer units within the copolyester chains, revealing a random distribution of hydroxyhexanoate (HH) and hydroxybutyrate (HB) units along the PHBH chains. X-ray diffraction (XRD) patterns demonstrated partial crystallinity in the PHBH samples. The thermal properties, including glass transition temperature (Tg), melting temperature (Tm), and melting enthalpy (ΔHm), were found to be lower in PHBH than in poly(R)-3-hydroxybutyrate (PHB), suggesting a broader application potential for the tested PHBH biopolyesters.

Decorin Knockdown Improves Aged Tendon Healing by Enhancing Recovery of Viscoelastic Properties, While Biglycan May Not.

The objective of the study was to determine the specific roles of decorin and biglycan in the early and late phases of tendon healing in aged mice. Aged (300 day-old) female wildtype (WT), Dcnflox/flox (I-Dcn-/-), Bgnflox/flox (I-Bgn-/-), and compound Dcnflox/flox/Bgnflox/flox (I-Dcn-/-/Bgn-/-) mice with a tamoxifen (TM) inducible Cre underwent a bilateral patellar tendon injury (PT). Cre excision of the conditional alleles was induced at 5days (samples collected at 3 and 6weeks) or 21days post-injury (samples collected at 6weeks). Scar tissue area, collagen architecture, gene expression and mechanical properties were assessed during re-establishment of tendon architecture after injury. Fibril diameter distribution was impacted by both decorin and biglycan knockdown at 3 and 6weeks compared to WT. Although early healing appeared to be delayed in the I-Bgn-/- tendons (larger scar tissue area at 3weeks), no differences in failure properties were detected. By 6weeks, in the I-Dcn-/- tendons, we observed a better recovery of viscoelastic properties compared to the WT tendons (reduced stress relaxation and increased dynamic modulus) when the knockdown was induced early. This could be explained by the increased expression of other matrix proteins, such as elastin whose gene expression was increased at 3weeks in the I-Dcn-/- tendons. Despite an impact on collagen fibrillogenesis, decorin and/or biglycan knockdown did not produce a detectable effect on quasi-static properties after patellar tendon injury. However, early decorin knockdown resulted in better recovery of viscoelastic properties. Mechanisms underlying this result remained to be clarified in further studies.

Grey-Box Energy Modelling of Energy-Efficient House Using Hybrid Optimization Technique of Genetic Algorithms (GA) and Quasi-Newton Algorithms with Markov Chain Monte Carlo Uncertainty Distribution

Understanding energy demands and costs is important for policy makers and the energy sector, especially in the context of residential heating and cooling systems. To estimate the thermal demand of a residential house, a grey-box modelling method with a resistance–capacitance (RC) analogy was implemented. The architectural properties used to parameterize the grey-box model were derived from a house used for research purposes in Vaughan, Ontario, Canada (TRCA-House A). The house model accounts for solar irradiance on exterior building surfaces, thermal conductivity through all surfaces, solar heat gains through windows, and thermal gains from ventilation. Two parallel short- and long-term calibrations were performed such that model outputs reflected the real-world operation of the house as best as possible. To define the unknown model parameters (such as the conductivity of building materials and some constant parameters), a hybrid optimization scheme including a genetic algorithm (GA) and the Quasi-Newton algorithm was introduced and implemented using Bayesian approximation and Markov Chain Monte Carlo (MCMC) methods. The temperature outputs from the model were compared to the data retrieved from TRCA-House A. The final iteration of the model had an RMSE for interior zone temperature estimation of 0.22 °C when compared to the retrieved interior zone temperature data from TRCA-House A. Furthermore, the annual heating and cooling energy consumption values are within 1.50% and 0.08% of target values, respectively. According to these preliminary results, the introduced model and optimization techniques could be adjusted for different types of housing, as well as for smart control applications on both a short- and long-term basis.

Individualized muscle architecture and contractile properties of ankle plantarflexors and dorsiflexors in post-stroke individuals.

This study was to investigate alterations in contractile properties of the ankle plantar- and dorsiflexors in post-stroke individuals. The correlation between muscle architecture parameters and contractile properties was also evaluated. Eight post-stroke individuals and eight age-matched healthy subjects participated in the study. Participants were instructed to perform maximal isometric contraction (MVC) of ankle plantar- and dorsiflexors at four ankle angles, and isokinetic concentric contraction at two angular velocities. B-mode ultrasound images of gastrocnemius medialis (GM) and tibialis anterior (TA) were collected simultaneously during the MVC and isokinetic measurements. Individualized torque-angle and torque-angular velocity relations were established by fitting the experimental data using a second-order polynomial and a rectangular hyperbola function, respectively. Muscle structure parameters, such as fascicle length, muscle thickness and pennation angle of the GM and TA muscles were quantified. Post-stroke subjects had significantly smaller ankle plantarflexor and dorsiflexor torques. The muscle structure parameters also showed a significant change in the stroke group, but no significant difference was observed in the TA muscle. A narrowed parabolic shape of the ankle PF torque-fiber length profile with a lower width span was also found in the stroke group. This study showed that the contractile properties and architecture of ankle muscles in post-stroke individuals undergo considerable changes that may directly contribute to muscle weakness, decreased range of motion, and impaired motion function in individuals after stroke.