Mechanical Function Research Articles

Multifunctional seamless meta-sandwich composite as lightweight, load-bearing, and broadband-electromagnetic-wave-absorbing structure

Engineered porous geometries composed of low-density lossy materials are promising as broadband absorbers due to their tunable structural attenuation that can selectively manipulate electromagnetic (EM) waves. However, the exposed cellular architectures require mechanical reinforcement and additional packaging. Here, we present a multifunctional meta-sandwich structure as one seamlessly integrated component composed of functional faceplates and dielectric lossy material-based octet-truss geometries toward a lightweight, load-bearing, and high-performance broadband EM wave absorber. EM responses are explored in the 4–18 GHz range by varying material combinations and multilayers of the upper-lower faceplates and the octet-truss core, elucidating the absorbing mechanisms of meta-sandwich structures. Multi-material 3D printing that streamlines the production of the seamless meta-sandwich composite into a single step implements the devised design that simultaneously excel in EM wave absorption and mechanical functionalities. The fabricated composite in a thin, single-layer structure comprising a transmitting upper faceplate, a dielectric lossy core, and a reflecting lower faceplate, achieves an average absorption rate of 95.0 % and a broadband reflection loss (≤-10 dB) over the entire measured bandwidth. Furthermore, flexural testing confirms superior bending resistance compared to conventional honeycomb structures. The multi-materials meta-sandwich design will inspire versatile multifunctionalities enabled by rationally combining mechanical metamaterials and functional housing.

Vector synthesis of fault testing map for logic

Vector synthesis of fault testing (simulation) map for logic is proposed, which without simulation allows to determine of all faults detected on test sets, as well as determining test sets to detect specified faults. For synthesis, a superposition of smart data structures is used, containing: a deductive matrix D, as a derivative of the logical vector L, test truth table T, and fault truth table F. The deductive matrix is seen as the gene of functionality and base of fault simulation mechanism to solve all the problems of testing and verification. In the matrix synthesis, an axiom is used: all the mentioned tables are identical in shape to each other and always interact with each other convolutionally T⊕L⊕F=0. A universal deductive reversing converter “test-faults” and “faults-test” for logical functionalities of any dimension is proposed. Converter functions: fault simulation on test sets T→F and synthesis of test sets F→T to detect the specified faults. The converter can be used as a test generation and fault simulation service for IP-core system-on-chip (SoC) under the IEEE 1500 SECT standard. Based on the deductive matrix, a fault testing map for logic is built, where each test set is matched with the logic-detected faults of the input lines.

Combined use of CLP290 and bumetanide alleviates neuropathic pain and its mechanism after spinal cord injury inrats.

We aimed to explore whether the combination of CLP290 and bumetanide maximally improves neuropathic pain following spinal cord injury (SCI) and its possible molecular mechanism. Rats were randomly divided into five groups: Sham, SCI + vehicle, SCI + CLP290, SCI + bumetanide, and SCI + combination (CLP290 + bumetanide). Drug administration commenced on the 7th day post-injury (7 dpi) and continued for 14 days. All rats underwent behavioral assessments for 56 days to comprehensively evaluate the effects of interventions on mechanical pain, thermal pain, cold pain, motor function, and other relevant parameters. Electrophysiological assessments, immunoblotting, and immunofluorescence detection were performed at different timepoints post-injury, with a specific focus on the expression and changes of KCC2 and NKCC1 proteins in the lumbar enlargement of the spinal cord. CLP290 and bumetanide alleviated SCI-associated hypersensitivity and locomotor function, with the combination providing enhanced recovery. The combined treatment group exhibited the most significant improvement in restoring Rate-Dependent Depression (RDD) levels. In the combined treatment group and the two individual drug administration groups, the upregulation of potassium chloride cotransporter 2 (K+-Cl-cotransporter 2, KCC2) expression and downregulation of sodium potassium chloride cotransporter 1 (Na+-K+-Cl-cotransporter 1, NKCC1) expression in the lumbar enlargement area resulted in a significant increase in the KCC2/NKCC1 ratio compared to the SCI + vehicle group, with the most pronounced improvement seen in the combined treatment group. Compared to the SCI + vehicle group, the SCI + bumetanide group showed no significant paw withdrawal thermal latency (PWTL) improvement at 21 and 35 dpi, but a notable enhancement at 56 dpi. In contrast, the SCI + CLP290 group significantly improved PWTL at 21 days, with non-significant changes at 35 and 56 days. At 21 dpi, KCC2 expression was marginally higher in monotherapy groups versus SCI + vehicle, but not significantly. At 56 dpi, only the SCI + bumetanide group showed a significant difference in KCC2 expression compared to the control group. Combined application of CLP290 and bumetanide effectively increases the ratio of KCC2/NKCC1, restores RDD levels, enhancesGABAA receptor-mediated inhibitory function in the spinal cord, and relieves neuropathic pain in SCI; Bumetanide significantly improves neuropathic pain in the long term, whereas CLP290 demonstrates a notable short-term effect.

Abstract P455: Integrins play a role in stress relaxation of perivascular adipose tissue

Perivascular adipose tissue (PVAT) is well known for being anti-contractile (reducing potency, maximum) in healthy tissues. We discovered a new function of PVAT, the ability to stress relax in response to a stretch. This is of note because stress relaxation has been attributed largely to smooth muscle, of which PVAT has none that is organized in a functional layer. Here we test the hypothesis that stress relaxation depends on the interactions of the cell membrane delimited heterodimer integrins with collagen. Our model is the thoracic aorta of the male Dahl SS rat on a normal diet. The PVAT and aorta were physically separated for most assays. Results from snRNA seq in PVAT, histochemistry and isometric contractility were used. Collagen was evident in PVAT as stained by Masson Trichrome. snRNA seq of whole PVAT determined expression of many collagen isoforms and integrins, with mRNA for both the α1 and β1 integrin being most highly expressed. Isolated aortic rings and separated PVAT were challenged with 2 or 4 grams of passive tension. Pharmacological inhibition of integrin/collagen interaction was effected by the specific α1β1 distintegrin obtustatin (5 uM) or general inhibitor RGD peptide (1 mM). RGD peptide but not obtustatin reduced the ability of the isolated PVAT ring to maintain applied tone at both the 2 and 4 gram challenge (~15% gain in relaxation/loss of tone, figure ). By contrast, stress relaxation in the aorta itself was not reduced by either inhibitor. In addition to a1b1 and collagen interaction, cell-cell communication inference identified integrins av and a5, two major RGD motif containing isoforms, as potential partners of collagens with fibroblast-like cells most likely involved. Collectively, these findings validate that stress relaxation can occur in a non-smooth muscle tissue, doing so at least in part through integrin-collagen interactions that may not include α1β1 heterodimers. The importance of this lies in considering PVAT as a vascular layer that possesses mechanical functions.

Revealing chemistry-structure-function relationships in shark vertebrae across length scales

Shark cartilage presents a complex material composed of collagen, proteoglycans, and bioapatite. In the present study, we explored the link between microstructure, chemical composition, and biomechanical function of shark vertebral cartilage using Polarized Light Microscopy (PLM), Atomic Force Microscopy (AFM), Confocal Raman Microspectroscopy, and Nanoindentation. Our investigation focused on vertebrae from Blacktip and Shortfin Mako sharks. As typical representatives of the orders Carcharhiniformes and Lamniformes, these species differ in preferred habitat, ecological role, and swimming style. We observed structural variations in mineral organization and collagen fiber arrangement using PLM and AFM. In both sharks, the highly calcified corpus calcarea shows a ridged morphology, while a chain-like network is present in the less mineralized intermedialia. Raman spectromicroscopy demonstrates a relative increase of glucosaminocycans (GAGs) with respect to collagen and a decrease in mineral-rich zones, underlining the role of GAGs in modulating bioapatite mineralization. Region-specific testing confirmed that intravertebral variations in mineral content and arrangement result in distinct nanomechanical properties. Local Young's moduli from mineralized regions exceeded bulk values by a factor of 10. Overall, this work provides profound insights into a flexible yet strong biocomposite, which is crucial for the extraordinary speed of cartilaginous fish in the worlds’ oceans. Statement of significanceShark cartilage is a morphologically complex material composed of collagen, sulfated proteoglycans, and calcium phosphate minerals. This study explores the link between microstructure, chemical composition, and biological mechanical function of shark vertebral cartilage at the micro- and nanometer scale in typical Carcharhiniform and Lamniform shark species, which represent different vertebral mineralization morphologies, swimming styles and speeds. By studying the intricacies of shark vertebrae, we hope to lay the foundation for biomimetic composite materials that harness lamellar reinforcement and tailored stiffness gradients, capable of dynamic and localized adjustments during movement.

Integration of Diffusion Transformer and Knowledge Graph for Efficient Cucumber Disease Detection in Agriculture.

In this study, a deep learning method combining knowledge graph and diffusion Transformer has been proposed for cucumber disease detection. By incorporating the diffusion attention mechanism and diffusion loss function, the research aims to enhance the model's ability to recognize complex agricultural disease features and to address the issue of sample imbalance efficiently. Experimental results demonstrate that the proposed method outperforms existing deep learning models in cucumber disease detection tasks. Specifically, the method achieved a precision of 93%, a recall of 89%, an accuracy of 92%, and a mean average precision (mAP) of 91%, with a frame rate of 57 frames per second (FPS). Additionally, the study successfully implemented model lightweighting, enabling effective operation on mobile devices, which supports rapid on-site diagnosis of cucumber diseases. The research not only optimizes the performance of cucumber disease detection, but also opens new possibilities for the application of deep learning in the field of agricultural disease detection.

Quantitative design criterion for mechanical interface functionalization regarding adhesion strength in chemically pre-treated polymer-metal hybrids using fractal dimension

ABSTRACT Polymer-metal hybrids (PMH) are common lightweight materials, whereas adhesion between metal and polymer is largely determined by the metallic surface design. Approaches in interface functionalization comprise both, mechanical and chemical surface modification. Therefore, surface modification on aluminum EN AW-6082 has been conducted prior to thermal joining to glass-fiber reinforced polyamide 6. Laser beam machining with a variation of structure density was carried out to produce defined groove structures. In addition, chemical surface modification by Boehmite hot water treatment as well as organo-silane couple agents were realized. Subsequently, the joint strength was assessed in lap shear tests. In order to quantitatively correlate the features of surface structure to the joint strength, regression analysis considering different chemical states were conducted. Hereby, the surface structure was represented on the one hand by the structure density and on the other hand by the calculated fractal dimension on cross-sectional images. The results revealed that using both, mechanical and chemical surface modification by laser machining as well as silanization, not only added together but moreover acted beneficial to each other. In addition, the fractal dimension proved to be a promising design criterion for linear correlation of joint strength independent of the chemical state.

Branch differentiation of financial mechanisms of enterprise restructuring

In the paper, the financial mechanism of enterprise restructuring is interpreted as a complex process, the object of comprehensive analysis, clear planning, effective implementation, the implementation of which allows enterprises to restore financial stability, increase competitiveness and ensure sustainable development in the long term. It has been proven that the general principles of the functioning of the financial restructuring mechanism are: transparent business conduct, openness in communication, mutual benefit, reaching consensus, analysis of all aspects of activity, integration of various measures, realistic goals, financial flexibility, constant monitoring, reporting to stakeholders, innovativeness, proactivity , flexibility and operational adaptation, alternative, optimality, etc. Adherence to the specified principles ensures the successful implementation of financial restructuring, increases trust in the enterprise and contributes to achieving its financial stability. It is shown that the sectoral differentiation of financial mechanisms of enterprise restructuring allows taking into account the specifics of each industry, ensuring effective management of financial risks and optimization of resources. Successful restructuring requires an individual approach that takes into account the unique needs and operating conditions of each enterprise. Based on the results of summarizing the experience of the functioning of financial mechanisms in various branches of the national economy, it was established that they differ in various aspects of restructuring, which can be of the following nature: adaptive, structural, structural-adaptive, integrative, security-oriented, reengineering of business processes. General financial instruments that can be used in all branches of the national economy are substantiated - state financing programs through the use of state grants, subsidies and credit programs to support restructuring measures, as well as public-private partnerships based on the involvement of private investors for joint financing of infrastructure projects.

Engineering static non-reciprocity in mechanical metamaterials

Non-reciprocity has recently been achieved in static fields by mechanical metamaterial that combines large non-linearity and asymmetric geometry. Novel devices are then designed to obtain one-way mechanical functionalities. Non-linearity is the fundamental part that regulates static non-reciprocity, but the influential path remains difficult to quantify. In this work, we employ the geometrically exact beam model to obtain the nonlinear deformation profile of mechanical metamaterials, and build nonlinear equations that govern the deformation behavior. A new two-step method is proposed to solve the nonlinear governing equations, which avoids Jacobi matrix singularity. We establish an accurate model that predicts the non-reciprocal mechanical behavior and verify its accuracy by finite element method. To gain further insight into non-linearity’s influences on mechanical non-reciprocity, we investigate mechanical metamaterials with curved beams, explore the effects of initial curvature on non-reciprocity, and engineer their non-reciprocity to obtain different non-reciprocal force–displacement responses. Our work offers beneficial vehicles to realize static direction-selective functionalities, contributing to shock absorption, vibration damping, and mechanical energy manipulation.

Characterization of Friction within a Novel 3 mm Wristed Robotic Instrument

Surgical robotic tools are being developed for a variety of surgical procedures that are executed within small workspaces. Novel designs of miniaturized cable-actuated surgical tools for cleft palate repair have previously been developed. However, the behavior and significance of friction within these tools are largely unknown. A study was conducted to investigate the friction in a pulleyless 3 mm diameter wristed instrument. The wrist utilizes cable guide channels that allow for miniaturization at the cost of increased friction. An experimental rig was developed to measure friction within the wrist link mechanism when the tool is positioned at various pitch angles. A strong relationship between the cable tension and the tool’s pitch angle was found as a result of friction. The cable tension increased as the pitch angle approached extreme values (percent increases in the cable tension of 33% and 67.3% at a pitch of 90° and −90°, respectively). However, the resultant cable tension was below the failure strength of the cable, indicating that the design is feasible. The results of this study would be useful to those considering the design of miniature robotic surgical tools that are cable-driven. Significant tool reduction can be achieved by employing static guide channels for the cables, forgoing the use of additional moving components like pulleys while maintaining cable tension well within its break strength. Future work in the design and optimization of novel miniaturized wrist mechanisms should consider frictional effects and their impact on mechanism function.

Simultaneous optical imaging of gastric slow waves and contractions in the in vivo porcine stomach.

Gastric peristalsis is governed by electrical "slow waves" generally assumed to travel from proximal to distal stomach (antegrade propagation) in symmetric rings. Although alternative slow-wave patterns have been correlated with gastric disorders, their mechanisms and how they alter contractions remain understudied. Optical electromechanical mapping, a developing field in cardiac electrophysiology, images electrical and mechanical physiology simultaneously. Here, we translate this technology to the in vivo porcine stomach. Stomachs were surgically exposed and a fluorescent dye (di-4-ANEQ(F)PTEA) that transduces the membrane potential (Vm) was injected through the right gastroepiploic artery. Fluorescence was excited by LEDs and imaged with one or two 256 × 256 pixel cameras. Motion artifact was corrected using a marker-based motion-tracking method and excitation ratiometry, which cancels common-mode artifact. Tracking marker displacement also enabled gastric deformation to be measured. We validated detection of electrical activation and Vm morphology against alternative nonoptical technologies. Nonantegrade slow waves and propagation direction differences between the anterior and posterior stomach were commonly present in our data. However, sham experiments suggest they were a feature of the animal preparation and not an artifact of optical mapping. In experiments to demonstrate the method's capabilities, we found that repolarization did not always follow at a fixed time behind activation "wavefronts," which could be a factor in dysrhythmia. Contraction strength and the latency between electrical activation and contraction differed between antegrade and nonantegrade propagation. In conclusion, optical electromechanical mapping, which simultaneously images electrical and mechanical activity, enables novel questions regarding normal and abnormal gastric physiology to be explored.NEW & NOTEWORTHY This article introduces a novel method for imaging gastric electrophysiology and mechanical function simultaneously in anesthetized, open-abdomen pigs. We demonstrate it by observing propagating slow-wave depolarization and repolarization along with the strength, spatial distribution, and direction of contractions. In addition, we observe that in this animal preparation, slow waves often do not propagate from the proximal to distal stomach and are frequently asymmetric between the anterior and posterior sides of the stomach.

Characterization of Trabecular Bone Microarchitecture and Mechanical Properties Using Bone Surface Curvature Distributions.

Understanding bone surface curvatures is crucial for the advancement of bone material design, as these curvatures play a significant role in the mechanical behavior and functionality of bone structures. Previous studies have demonstrated that bone surface curvature distributions could be used to characterize bone geometry and have been proposed as key parameters for biomimetic microstructure design and optimization. However, understanding of how bone surface curvature distributions correlate with bone microstructure and mechanical properties remains limited. This study hypothesized that bone surface curvature distributions could be used to predict the microstructure as well as mechanical properties of trabecular bone. To test the hypothesis, a convolutional neural network (CNN) model was trained and validated to predict the histomorphometric parameters (e.g., BV/TV, BS, Tb.Th, DA, Conn.D, and SMI), geometric parameters (e.g., plate area PA, plate thickness PT, rod length RL, rod diameter RD, plate-to-plate nearest neighbor distance NNDPP, rod-to-rod nearest neighbor distance NNDRR, plate number PN, and rod number RN), as well as the apparent stiffness tensor of trabecular bone using various bone surface curvature distributions, including maximum principal curvature distribution, minimum principal curvature distribution, Gaussian curvature distribution, and mean curvature distribution. The results showed that the surface curvature distribution-based deep learning model achieved high fidelity in predicting the major histomorphometric parameters and geometric parameters as well as the stiffness tenor of trabecular bone, thus supporting the hypothesis of this study. The findings of this study underscore the importance of incorporating bone surface curvature analysis in the design of synthetic bone materials and implants.

Thermal decomposition kinetics and storage life prediction of nitramine propellants with different energetic plasticizers based on model-fitting method

The research on the thermal decomposition of propellant is critical to determining its safe storage life. The thermogravimetry (TG) testing of nitramine propellants plasticized by nitroglycerin (NG), glycidyl azide polymer (GAP), 2,2-dinitropropanol hexanoate (DNPH), and N-butyl-2-nitratoethylnitramine (BuNENA) was performed under non-isothermal circumstances. The thermal decomposition mechanism of propellant was then analyzed using the model-fitting method, and the storage life was predicted based on the mechanism. The results show that when heated to the same mass loss, the temperature of GAP-NC-RDX, BuNENA-NC-RDX, and DNPH-NC-RDX is higher than that of NG-NC-RDX. GAP-NC-RDX, BuNENA-NC-RDX, and DNPH-NC-RDX propellants have superior thermal stability to that of NG-NC-RDX. The kinetic mechanism functions and equations of the propellants were calculated, and multi-step reaction models of the thermal decomposition were built. The major thermal decomposition mechanism of nitramine propellants was discovered to be composite autocatalytic decomposition (Kamal-Sourour equation), which means that the reaction of reactants and the reaction catalyzed by products occur in tandem. The decomposition depth of propellants increases as the temperature rises during the same storage time. The storage lifetimes of GAP-NC-RDX, BuNENA-NC-RDX, DNPH-NC-RDX, and NG-NC-RDX propellants at 288 K are 28.71 years, 24.49 years, 18.34 years, and 16.33 years, respectively. The inclusion of GAP, DNPH, and BuNENA in the formulation improves the storage life of propellant more than NG. This study offers an attractive strategy for analyzing the decomposition mechanism of propellant with a multi-step decomposition reaction and forecasting its storage life.

Unveiling the mechanical role of radial fibers in meniscal tissue: Toward structural biomimetics

The meniscus tissue is crucial for knee joint biomechanics and is frequently susceptible to injuries resulting in early-onset osteoarthritis. Consequently, the need for meniscal substitutes spurs ongoing development. The meniscus is a composite tissue reinforced with circumferential and radial collagenous fibers; the mechanical role of the latter has yet to be fully unveiled.Here, we investigated the role of radial fibers using a synergistic methodology combining meniscal tissue structure imaging, a computational knee joint model, and the fabrication of simple biomimetic composite laminates. These laminates mimic the basic structural units of the meniscus, utilizing longitudinal and transverse fibers equivalent to the circumferential and radial fibers in meniscal tissue.In the computational model, the absence of radial fibers resulted in stress concentration within the meniscus matrix and up to 800 % greater area at the same stress level. Furthermore, the contact pressure on the tibial cartilage increased drastically, affecting up to 322 % larger areas. Conversely, in models with radial fibers, we observed up to 25 % lower peak contact pressures and width changes of less than 0.1 %. Correspondingly, biomimetic composite laminates containing transverse fibers exhibited minor transverse deformations and smaller Poisson's ratios. They demonstrated structural shielding ability, maintaining their mechanical performance with the reduced amount of fibers in the loading direction, similar to the ability of the torn meniscus to carry and transfer loads to some extent. These results indicate that radial fibers are essential to distribute contact pressure and tensile stresses and prevent excessive deformations, suggesting the importance of incorporating them in novel designs of meniscal substitutes. Statement of significanceThe organization of the collagen fibers in the meniscus tissue is crucial to its biomechanical function. Radially oriented fibers are an important structural element of the meniscus and greatly affect its mechanical behavior. However, despite their importance to the meniscus mechanical function, radially oriented fibers receive minor attention in meniscal substitute designs. Here, we used a synergistic methodology that combines imaging of the meniscal tissue structure, a structural computational model of the knee joint, and the fabrication of simplistic biomimetic composite laminates that mimic the basic structural units of the meniscus. Our findings highlight the importance of the radially oriented fibers, their mechanical role in the meniscus tissue, and their importance as a crucial element in engineering novel meniscal substitutes.

THE CORRELATION OF COMMUNITY KNOWLEDGE LEVELS ABOUT FIRST AID IN CONDITIONS OF UNCONSCIOUSNESS WITH COMMUNITY READINESS TO PROVIDE BASIC LIFE SUPPORT IN DUKUHKARYA VILLAGE IN 2022

Basic life support is a basic aspect of rescue measures related to cardiac arrest. Basic life support can be taught to anyone. Providing and evaluating basic life support in the prehospital range can occur anywhere at any time, so the role special lay people and health members is expected to be able to take action to handle emergency conditions. Cardiac arrest is a condition where the mechanical function of the heart suddenly stops, which is reversible with appropriate treatment but will cause death if not treated immediately. Community knowledge is generally good in performing basic life support. The research method used is quantitative with cross-sectional analytic research. The population in this study is the community of Rt 001 Rw 001 totaling 104 respondents. The data collection technique was using purposive sampling. It was found that with a significant level of 100% or a value of 5% (0.05) the Chi Square test results obtained p value (0.000) < value (0.05). There is a correation of the level of community knowledge about first aid in an unconscious condition with the community's readiness to carry out basic life support in Dukuhkarya Village in 2022. There is a the correlation of community knowledge about first aid in an unconscious condition with the community's readiness to carry out basic life support in Dukuhkarya Village in 2022. There is a the correlation of community knowledge about first aid in an unconscious condition with the community's readiness to carry out basic life support in Dukuhkarya Village in 2022.

Improving breaking efficiency of hard rock: Research on the mechanism of impact-shear rock breaking technology

To expedite drilling operations in hard rock of coal mines, a new type of impact-shear drill bit was developed, and its mechanism of speed-up and efficiency increase was studied. The RHT constitutive model was used to describe the structural behavior of rock, and the rock-breaking simulation model of full-size bit was established. Compared with PDC bit and hammer bit, the rock-breaking force, bit torque, and rock stress characteristics of impact-shear bit were analyzed. The results show that, in comparison to PDC bit and hammer bit, the axial force of impact-shear bit was reduced by 68.25% and 71.40%, respectively, and the average torque was reduced by 91.79% and 83.36%, respectively. Notably, for the impact-shear bit, the fluctuation of drilling force was effectively mitigated, the stick–slip vibration of bit was weakened, the rock-breaking energy consumption was drastically reduced, and the rock-breaking efficiency and bit’s life were finally improved. In terms of rock stress characteristics, the pre-impact effect of the central hammer bit of the impact-shear bit can release the internal stress of the rock well, and the stress of the rock element on the hole wall was relatively reduced, thus making it easier for the external PDC bit to break the rock. Field test results show that, under the condition of the small drilling rig, the impact-shear bit can give full play to the pre-crushing function of the impact mechanism, thereby effectively protecting the PDC cutter of external PDC bit, and realizing the fast hole-forming in hard rock of coal mine.

The structural organization of the outer tissues in the gametophytic stem of the umbrella moss Hypnodendron menziesii optimizes load bearing.

The ultrastructural design and biochemical organization of the significantly thickened outer tissues of the gametophytic stem of Hypnodendron menziesii optimizes load bearing of the stem. Hypnodendron menziesii is a bryoid umbrella moss growing in high humid conditions on the forest floors of New Zealand. The erect gametophyte bears up to eight whorls of branches in succession, spreading across the stem that bears the heavy weight of branches with highly hydrated leaves. Our investigation using a combination of light microscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and TEM-immunolabeling techniques provided novel information on the structural design and biochemical organization of greatly thickened cell walls of epidermal, hypodermal, and outermost cortical tissues, comparing underlying thin-walled cortical tissues in the gametophytic stem. Probing into the ultrastructure of the cell wall architecture of these target tissues by TEM and SEM revealed the cell walls to display a multilamellar organization, in addition to demonstrating the presence of an electron-dense substance in the cell wall, presumably flavonoids. The pattern of distribution and concentration of rhamnogalacturonan, homogalacturonan, and heteromannan, as determined by immunogold labeling, suggests that it is the combination of structural and molecular design of the cell wall that may optimize the mechanical function of the epidermal, hypodermal, and outer cortical tissues. Statistical relationships between the overall thickness of epidermal, hypodermal, and outer cortical cell walls, the lumen area of cells and the percentage area of cell wall occupied in these tissues at different heights of the stem, and thickness of secondary cell wall layers (L1-L4/5) were explored. The results of these analyses unequivocally support the contribution of outer tissues to the mechanical strength of the resilient stem.

Comprehensive analysis of recurrence factors in cryoballoon AF ablation: integrating clinical, biomarkers, and echocardiographic parameters.

Atrial fibrillation (AF) poses substantial challenges in cardiovascular diseases, impacting patient health and economic burdens. Understanding the mechanical effects of AF on the left atrium (LA) and assessing the influence of treatment modalities on LA functions are critical. This study aims to assess the efficacy of echocardiographic and biochemical parameters in predicting AF recurrence following second generation cryoballoon ablation (CB-2). Ninety-two patients with symptomatic AF, treated with CB-2 at Istanbul University-Cerrahpaşa, Faculty of Medicine, Department of Cardiology, were prospectively examined from January 2021 to July 2023. The study endeavors to develop a predictive model for AF recurrence, investigating the relationship between echocardiographic measurements and serum biomarkers with recurrence. The follow-up duration for echocardiographic assessments and biochemical analyses was systematically documented. The study revealed a significant enhancement in LA mechanical functions during echocardiographic follow-ups three months post-procedure. Specifically, LA strain parameters emerged as significant predictors of recurrence (LAsr: 95%CI 1.004-1.246, p = 0.047; LAsct: 95%CI 1.040-1.750, p = 0.024). Biochemical analyses demonstrated a correlation between elevated PRO-BNP levels and an increased risk of recurrence (95%CI 1.000-1.003, p = 0.012). Moreover, specific biomarkers such as MYBPHL, which demonstrated increased levels post-procedure, were deemed indicative of atrial damage, suggesting potential additional atrial substrate modification beyond PVI. Consequently, improvements in LA function post-cryoballoon ablation and biochemical markers have surfaced as potential indicators for predicting AF recurrence. This study elucidates the effectiveness of CB-2 in treating AF and its impact on LA functions. Notably, LA strain measurements and PRO-BNP levels have emerged as reliable indicators for predicting recurrence. Beyond clinical implications, our research establishes a foundation for a deeper understanding of the role of CB-2 in AF management and factors associated with recurrence.

High energy density picoliter-scale zinc-air microbatteries for colloidal robotics.

The recent interest in microscopic autonomous systems, including microrobots, colloidal state machines, and smart dust, has created a need for microscale energy storage and harvesting. However, macroscopic materials for energy storage have noted incompatibilities with microfabrication techniques, creating substantial challenges to realizing microscale energy systems. Here, we photolithographically patterned a microscale zinc/platinum/SU-8 system to generate the highest energy density microbattery at the picoliter (10-12 liter) scale. The device scavenges ambient or solution-dissolved oxygen for a zinc oxidation reaction, achieving an energy density ranging from 760 to 1070 watt-hours per liter at scales below 100 micrometers lateral and 2 micrometers thickness in size. The parallel nature of photolithography processes allows 10,000 devices per wafer to be released into solution as colloids with energy stored on board. Within a volume of only 2 picoliters each, these primary microbatteries can deliver open circuit voltages of 1.05 ± 0.12 volts, with total energies ranging from 5.5 ± 0.3 to 7.7 ± 1.0 microjoules and a maximum power near 2.7 nanowatts. We demonstrated that such systems can reliably power a micrometer-sized memristor circuit, providing access to nonvolatile memory. We also cycled power to drive the reversible bending of microscale bimorph actuators at 0.05 hertz for mechanical functions of colloidal robots. Additional capabilities, such as powering two distinct nanosensor types and a clock circuit, were also demonstrated. The high energy density, low volume, and simple configuration promise the mass fabrication and adoption of such picoliter zinc-air batteries for micrometer-scale, colloidal robotics with autonomous functions.

Neck muscle function improves after neck exercises in individuals with whiplash-associated disorders: a case–control ultrasound study with speckle-tracking analyses

A whiplash injury can alter neck muscle function, which remains years after the injury and may explain why symptoms such as persistent pain and disability occur. There is currently limited knowledge about dynamic neck muscle function in chronic whiplash-associated disorders (WAD), and about the extent to which altered muscle function can improve after rehabilitation. Ultrasound can detect mechanical neck muscle function by measuring real-time deformation and deformation rate in the muscles. This method was used for five dorsal neck muscles in participants with chronic WAD versus matched controls in resistant neck rotation. We obtained real-time, non-invasive ultrasound measurements using speckle tracking, multivariate analyses, and mixed-design ANOVA analyses. The results showed altered deformation in the three deepest neck muscle layers, with less deformation area in the WAD group compared to controls in rotation to the most painful side at baseline. Participants in the WAD group performed three months of neck-specific exercises, resulting in improved deformation in the deep neck muscles in WAD and with a similar deformation pattern to controls, and the significant group differences ceased. We reveal new and important insights into the capability of ultrasound to diagnose altered neck muscle function and evaluate an exercise intervention.