Strength Measurements Research Articles

Green synthesis of CdS/flaxseed mucilage nanocomposite films using gamma irradiation for packaging applications

Abstract The most common ways to produce nanoparticles are through chemical and physical processes, which can be expensive and environmentally hazardous. Using plant extracts (green synthesis) as reducing and capping agents is a simple, cost-effective, and environmentally friendly method of lowering the usage of dangerous chemicals in the synthesis of metal nanoparticles. This study covers the environmentally friendly synthesis of cadmium sulphide nanoparticles (CdS NPs) using a blend of flaxseed extracts (FM), polyvinyl alcohol (PVA), and chitosan (Cs). The composites are then exposed to gamma irradiation at doses of 20 kGy and 40 kGy. UV–VIS absorption spectroscopy, SEM, HRTEM, EDX, and FTIR were used to analyse the produced nanocomposite films. UV–Vis absorption spectra showed considerable surface Plasmon resonance (SPR) bands at 396–440 nm, indicating that CdS NPs had been successfully synthesized. A progressive red shift in wavelength was noted, along with the broadening of the absorption band as the irradiation dose increased. Transmission electron microscopy pictures revealed that the generated CdS nanostructures were dispersed as spherical nanoparticles with remarkable structural homogeneity. Tensile strength and elongation measurements of the films revealed that the inclusion of CdS NPs improved their mechanical properties. The addition of CdS NPs to the current blends limits biodegradation in soil. Thermal gravimetric analysis findings showed that CdS NPs included in FM/PVA films had improved thermal stability. The antimicrobial activities of the tested films were performed against Staphylococcus aureus, Escherichia coli, and Candida albicans. The results revealed that all of the films exhibited more antibacterial activity against S. aureus than the two others, with the highest activity observed in nanocomposites with a high concentration of CdS.

Adhesion Stability According to Adhesion Area of Traditional Tile Gluing Method

In this study, verification was conducted through experiments to identify problems caused by traditional attachment methods in order to highlight the need for a suitable attachment method for new tile types according to changes in materials, production technology, and demand. The stability of adhesion strength was evaluated by subdividing the size of the adhesion area and adhesion strength measurement method for the country-type attachment method. The adhesion area on the back of the tile was divided into 60% and 80%, and the test specimens used in the experiment were tested for partial adhesion strength (Ta-1), overall adhesion strength (Ta-2), and adhesion strength after splitting (Ta-3), and the results were derived. As a result of conducting the adhesion test presented in the current national building standard tile specification (KCS 41 48 01) for 80% of the backfill area, the average adhesive strength was 0.85 N/mm2, and the standard strength was 0.39 N/mm2. However, as a result of the arithmetic average test of the adhesive strength of all tiles or cutting of the entire tile, rather than the partial adhesion test method of the mortar-attached part, it was confirmed that the adhesive strength was about −20% less than the current KCS 0.39 N/mm2.

Transference of outdoor gait-training to treadmill running biomechanics and strength measures: A randomized controlled trial

Outdoor gait-training has been successful in improving pain and reducing contact time during outdoor running for runners with exercise-related lower leg pain (ERLLP). However, it is unclear if these adaptations translate to gold standard treadmill running and clinical strength assessments. The study purpose was to assess the influence of a 4-week outdoor gait-training intervention with home exercises (FBHE) on treadmill running biomechanics and lower extremity strength compared to home exercises alone (HE) among runners with ERLLP. Seventeen runners with ERLLP were randomly allocated to FBHE and HE groups (FBHE: 3 M, 6F, 23 ± 4 years, 22.0 ± 4.6 kg/m2; HE: 3 M, 5F, 25 ± 5 years, 24.0 ± 4.0 kg/m2). Both groups completed eight sessions of home exercises over 4 weeks. The FBHE group received gait-training through wearable sensors to reduce contact time. Treadmill running gait and clinical strength assessments were conducted at baseline and 4-weeks. Multivariate repeated measures analyses of variance were used to assess the influence of group and timepoint for all outcomes. The FBHE group demonstrated significantly decreased contact time at 4-weeks compared to baseline and the HE group (Mean Difference [MD] range: −42 ms – −39 ms; p-range: <0.001–0.02). The FBHE group had significantly increased cadence (MD: +21 steps/min; p = 0.003) and decreased loading impulse (MD: −51, p < 0.001) during treadmill running at 4-weeks compared to the HE group. Strength did not significantly differ adjusting for multiple comparisons (p > 0.007). The outdoor FBHE intervention transferred to favorable changes in treadmill running biomechanics. Clinicians treating runners with ERLLP patients should implement data-driven outdoor gait-training to maximize patient benefits across running locations.

Use of a novel bluetooth-connected device to measure handgrip strength: A practical tool to help healthcare professionals identify adults at nutritional risk

Background and AimsLow muscle strength is strongly tied to poor nutrition status, and nutritional interventions are likewise linked to maintenance and restoration of muscle strength and functional status. Nutrition plays a vital role in muscle mass, strength, and function, and losses in muscle (strength, function, and mass) are associated with poor health outcomes and added costs for healthcare services. For this study of outpatients, the main objective was to identify those at risk for low muscle strength, as evidenced by low handgrip strength (HGS) measures with risk stratified by age and sex. MethodsThis was a two-part study on HGS measures in adults attending outpatient clinics in India. In part one, we conducted HGS tests on dominant and non-dominant hands of patients who qualified for the study. For HGS measures, we used a validated tool, the SQUEGG device, a smart handgrip trainer, along with its companion Bluetooth-connected app, the Muscle Strength Assessment Tool (MSAT) app. In part two, we collected Healthcare Practitioners’ (HCP) feedback via a short digital survey on the use of the SQUEGG device + the MSAT app to do HGS risk screening as an indicator of needed nutritional intervention. ResultsNearly a third of community-living adults in India exhibited low HGS among the 3036 sampled. At each age stratum, dominant-hand HGS in women was lower by 25% to 35% compared to men. Among 353 HCPs, 293 (83%) provided insights via survey, and 85% of surveyed HCPs (n=249) strongly agreed or agreed that the SQUEGG device + MSAT app helped them identify HGS issues among their patients, and 85% (n=248) agreed or strongly agreed they would like to continue using the SQUEGG device + MSAT app to inform their practice. Nearly all surveyed HCPs (98%, n=288) recommended an oral nutritional supplement (ONS) to their patients with identified low HGS. ConclusionsOur findings demonstrate that HCPs would like to continue use of the SQUEGG device + MSAT app as it helped them identify adult patients who had decreased HGS (about 30% of the study population), in turn identifying opportunities to use nutritional interventions such as ONS to address nutrition shortfalls and to restore functional status.

The Influence of Quartz Powder on the Mechanical–Thermal–Chemical–Durability Properties of Cement-Based Materials

Using industrial by-products to replace cement is an important way to reduce carbon emissions in the cement industry. The purpose of this article is to understand the effect of quartz powder on the properties of cement-based materials. Experimental studies were conducted on the macroscopic and microscopic properties of cement-based materials mixed with quartz powder to evaluate their feasibility as a replacement for cement. The substitution rates of quartz powder were 0% (Qu0), 7.5% (Qu7.5), and 15% (Qu15). The test time was from 1 day to 28 days, and the main results are as follows: In the early stage of the hydration reaction, as the amount of quartz powder substitution increases, the cumulative hydration heat increases. This is mainly because the nucleation effect of quartz powder accelerates the hydration reaction of cement. In the later stage of the hydration reaction, as the amount of quartz powder substitution increases, the cumulative heat of hydration decreases. This is mainly due to the diluting effect of quartz powder. For Qu0, Qu7.5, and Qu15, the decrease in compressive strength after 1 day is not obvious. The decrease in compressive strength at 28 days is more obvious. Overall, there are exponential relationships between the UPV measurement or surface resistivity results and the compressive strength measurement results at 1, 3, 7, and 28 days. The XRD test results show that the main products of the reaction are AFt, CH, Hc, and Mc. From Day 1 to Day 28, the content of Mc becomes evident. The test results for TG showed that, as the amount of quartz powder substitution increases, the mass loss decreases. For different specimens of Qu0, Qu7.5, and Qu15 at different test times (3 and 28 days), there is an exponential function relationship between chemically bound water and strength. A numerical hydration model is proposed for cement–quartz binary blends. The parameters of the hydration model are determined based on the hydration heat normalized by the cement mass. Moreover, the hydration heat at 28 days is calculated using the proposed model. The strength development of all specimens and all test ages can be expressed as an exponential function of hydration heat.

The Effect of Anti-fatigue Decoction on the Behaviors and Serological Indicators in a Central Fatigue Rat Model.

This study aimed to assess the effects of Anti-fatigue Decoction (AFD) against central fatigue by observing the behaviors and serological indicators of rats modeled by the modified multiple platform method (MMPM) after drug intervention. Grip strength measurements were used to evaluate the muscle strength of rats. The open field test was utilized to assess anxiety-like behavior, while the Morris water maze test was conducted to evaluate the memory function of the rats. Following the behavioral assessments, rat serum samples were collected to measure the concentrations of corticosterone (CORT) and lactic acid (LAC). The concentration of LAC was determined using the colorimetric method, while the concentration of CORT was measured using the enzyme-linked immunosorbent assay (ELISA) method. Compared to the blank control group, following MMPM modeling, rats exhibited significant reductions in grip strength and impaired ability to memory. The serum analysis revealed increased levels of LAC and CORT in the model group rats. AFD can noticeably reverse these adverse changes to a certain extent. These findings highlight the positive effects of AFD and coenzymeQ10 on physical and cognitive abilities and alterations in serum biomarker levels of central fatigue rats.

The Significance of Selected Myokines in Predicting the Length of Rehabilitation of Patients after COVID-19 Infection.

In the context of the global COVID-19 pandemic, understanding the intricate mechanisms of the body's response to infection and inflammation has become a priority for the medical and research communities. It has been proven that during COVID-19 infection, molecules are secreted-namely organokines, which may directly or indirectly play a role in the pathophysiology of COVID-19. The objective of this study was to scrutinize the potential correlation between the levels of selected myokines (myostatin, agrin, irisin, and myonectin) and the duration of rehabilitation in post-COVID-19 patients. Additionally, the study aimed to investigate whether there is a correlation between the levels of these myokines and the length of hospitalization during COVID-19 treatment. The study was conducted at the Rehabilitation Hospital in Szczecin (Poland). Patients in the study participated in a comprehensive rehabilitation program following COVID-19 treatment. In order to assess the effectiveness of rehabilitation, the following tests were performed: a 6 min walk test with an assessment of exercise tolerance (Borg scale), an assessment of dyspnea severity (mMRC scale), a spirometric assessment of respiratory function, a measurement of arm strength, and an assessment of fatigue using the Fatigue Assessment Scale (FAS). Myokine levels were measured using commercially available enzyme-linked immunosorbent assays (ELISA) according to the manufacturer's instructions. Statistical analysis was performed using Statistica 13.1 software. Lower concentrations of irisin and myonectin and higher concentrations of myostatin correlated with longer rehabilitation time. Baseline levels of specific myokines in post-COVID-19 patients could play a crucial role in anticipating the duration of rehabilitation. The duration of hospitalization for the infection may influence myokine levels in patients recovering from COVID-19.

Measuring the tensile properties of Ti6Al4V fabricated by laser powder bed fusion: Influence of specimen dimensions

This study presents the mechanical characterization of vertical Ti6Al4V tensile specimens produced by laser powder bed fusion (LPBF) processing and then heat-treated according to AMS2801 standard. The surfaces were kept in the as-built condition for the evaluations. Three rectangular specimen geometries were considered, with a reduced section of 6 × 6 × 25, 3 × 3 × 12.5, and 1 × 1.5 × 7 mm3 respectively. The surface roughness, length-scale of the microstructure, and average microhardness were compared and found to be unaffected by part section, in the range of sizes explored. The non-destructive measurement of the cross-sectional area of the tested specimens affected the accuracy on the measurement of the tensile strength. The use of conventional tools, such as calipers and micrometers, led to an overestimation of the cross-sectional area by 7 to 15 %, which caused an underestimation of the tensile stresses. When calculating the stress with the cross-sectional area measured from computed tomography images, the Young’s modulus, yield strength and ultimate tensile strength were comparable for all geometries. However, the elongation at break was 9 % for the smallest specimens compared to 12 % for ASTM E8 coupons. The reduction of ductility was explained by a higher slimness ratio for smaller specimens, in addition to an increased effect of pores and the surface roughness. These results highlight the importance of using specimens representative of a part wall thickness when characterizing the mechanical properties of LPBF Ti6Al4V. The methodological recommendations established in this study can be applied to other LPBF materials and other small scale manufacturing processes.

Design and application of a power frequency electric field measuring device for a high‐humidity environment

AbstractThe power frequency electric field is the most important electromagnetic environmental factor in alternating current power transmission projects. The humidity has a negative influence on available electric field measuring devices, which may lead to discrepancies of up to seven times the actual value at a relative humidity exceeding 80%. The changes in the support and probe shell impedance may be the reason for the error. The optimization measures include modifying the communication mode, designing a suitable structure and circuit for the probe, and using composite insulating material with strong hydrophobicity for the support. A three‐axis omnidirectional electric field measuring device was developed based on wireless communication and composite support. The variation of the measured electric field strength value is less than 1% at relative humidities ranging from 45% to 90% in the laboratory, and the measured results obtained in high humidity at the high‐voltage test site and under the transmission line demonstrated high accuracy. The research demonstrates that the composite support can be used to improve the performance of conventional devices. The proposed device can better meet the needs for accurate measurement of electric field strength in a high‐humidity environment and overcome the technical problems raised by the IEC standard.

Bank strength variability and its impact on the system-scale morphodynamics of the upper Amazon River in Brazil

Large anabranching rivers form channels in sediments of varying strength, resulting from erosional and depositional processes that act over geological time scales. Although bank strength variability is known to affect channel morphodynamics, its impact on the migration of large sand-bed rivers remains poorly understood. We report the first in situ measurements of bank strength from an ∼100-km-long reach of the Solimões River, the Brazilian Amazon River upstream of Manaus. These show that cohesive muds in Pleistocene terraces along the river’s right margin have bank strengths as much as three times greater than Holocene floodplain deposits composing the left bank. Image analysis suggests these resistant outcrops determine channel-bar dynamics: channel widening and bar deposition are inhibited, which lowers planform curvature and reduces erosion of the opposing bank. Planform analysis of the 1600-km-long Solimões River between 1984 and 2021 shows that where the channel is associated with Pleistocene terraces, lower rates of bank erosion and bar deposition are evident. Heterogeneity in bank strength is thus a first-order control on the large-scale morphodynamics of the world’s largest lowland river.

Comparison of Blood Flow Restriction Interventions to Standard Rehabilitation After an Anterior Cruciate Ligament Injury: A Systematic Review.

Blood flow restriction training (BFR-t) data are heterogeneous. It is unclear whether rehabilitation with BFR-t after an anterior cruciate ligament (ACL) injury is more effective in improving muscle strength and muscle size than standard rehabilitation. To review outcomes after an ACL injury and subsequent reconstruction in studies comparing rehabilitation with and without BFR-t. Systematic review. Level of evidence, 3. A search of English-language human clinical studies published in the past 20 years (2002-2022) was carried out in 5 health sciences databases, involving participants aged 18-65 undergoing rehabilitation for an ACL injury. Outcomes associated with muscle strength, muscle size, and knee-specific patient-reported outcome measures (PROMs) were extracted from studies meeting inclusion criteria and compared. The literature search identified 279 studies, of which 5 met the selection criteria. Two studies suggested that BFR-t rehabilitation after an ACL injury improved knee or thigh muscle strength and muscle size compared with rehabilitation consisting of comparable and higher load resistance training, with two studies suggesting the opposite. The single study measuring PROMs showed improvement compared to traditional rehabilitation, with no difference in muscle strength or size. BFR-t after an ACL injury seems to benefit muscle strength, muscle size, and PROM scores compared with standard rehabilitation alone. However, only 1 large study included all these outcomes, which has yet to be replicated in other settings. Further studies utilizing similar methods with a common set of outcome measures are required to confirm the effects of BFR-t on ACL rehabilitation.

Study on the use of different machine learning techniques for prediction of concrete properties from their mixture proportions with their deterministic and robust optimisation

The construction industry relies so heavily on concrete that it's crucial to precisely forecast and optimize the strength and workability of concrete mixtures, while reducing costs as much as possible. For this objective, this study tries to predict and optimize the compressive strength and workability (slump) of concrete by using deterministic and robust optimization approaches, so as to determine the optimum concrete mixture proportions, while minimizing cost. Specifically, strength and slump were predicted based on concrete mixture proportions with five different machine learning techniques—support vector machine (SVM), artificial neural network (ANN), fuzzy inference system (FIS), adaptive fuzzy inference system (ANIS), and genetic expression programming (GEP), based on a dataset comprising two hundred concrete mixtures, which has various levels of key ingredients, including cement, water, fine aggregate, coarse aggregate, and size of coarse aggregate, along with their associated measures of strength and workability. These ingredients were used as input parameters, while compressive strength and slump (representing workability) served as output parameters for each mix proportion. Experimental investigations were conducted on fifteen distinct concrete mixes to validate the performance of the five networks, finding that ANFIS can yield the best results both for training and validation. This study provides valuable insights for predicting concrete properties and optimizing concrete mixture proportions, thus helping to maximize strength and workability while minimizing costs.

Weak coupling strength measurement between two whispering-gallery-mode microresonators near an exceptional point

Sensing is one of the important applications of the whispering-gallery-mode (WGM) microresonator. Here we consider a model consisting of two WGM microresonators and one fiber waveguide. We show that the system can be near an exceptional point when the two tapers in the fiber waveguide are coupled to the two microresonators in a way that can lead to an unidirectional coupling. We propose a method to measure the weak coupling strength between the two microresonators. Compared to the conventional method, our method operates near an exceptional point and has the ability to measure smaller coupling strength.

Biocomposite Anchors Have Greater Yield Load and Energy Compared With All-Suture Anchors in an In Vitro Ovine Infraspinatus Tendon Repair Model

PurposeTo compare tensile fatigue and strength measures of biocomposite and all-suture anchors in an ovine humerus-infraspinatus tendon model of rotator cuff repair. MethodsInfraspinatus tendons on adult ovine humeri were sharply transected at the insertion. One of each pair was randomly assigned for fixation with two biocomposite or all-suture anchors. Constructs were tested with 200 cycles of 20-70 N tensile load and gap formation was measured at the incised tendon end every 50 cycles. They were subsequently tested to failure. Outcome measures including fatigue stiffness, hysteresis, creep and gap formation, and tensile stiffness, and yield and failure displacement, load, and energy were compared between anchors. ResultsBiocomposite anchors had higher yield load (134.1 ± 6.5 N, p<.01) and energy (228.6 ± 85.7 J, p<.03) than all-suture anchors (104.7 ± 6.5 N, 169.8 ± 85.7 J). Fatigue properties were not different between anchors, but stiffness and gap formation increased and hysteresis and creep decreased significantly with increasing cycle number. ConclusionsWhile the yield displacement of both anchors was within the range of clinical failure, the tensile yield load and energy of ovine infraspinatus tendons secured to the humerus with two single-loaded all-suture anchors in a single row were significantly lower than those secured with two biocomposite anchors in the same configuration. Clinical RelevanceIt is important to understand the biomechanical properties for selecting anchors for rotator cuff repair. A direct comparison of fatigue testing followed by failure strength of infraspinatus tendon fixation with all-suture and biocomposite anchors could help guide anchor selection and post-operative mobility recommendations.

Reliability and validity of the new portable Nordic hamstring test device (IVMES H-Bord)

The aim of this study is to determine the reliability and validity of the IVMES H-Bord eccentric hamstring strength measurement device. Thirty-eight healthy male athletes (age: 20.9 ± 2.11 years, height: 1.79 ± 0.03 m, body weight: 76.6 kg, body mass index: 22.6 ± 0.69 kg/m2) participated in this study. Each test protocol was applied in eccentric mode and isometric mode respectively. Between-session test-retest reliability of the IVMES H-Bord was analyzed for the intraclass correlation coefficient (ICC) with 95% coefficient intervals (CI). Validity of the IVMES H-Bord was examined for eccentric mode (NHTecc), and isometric mode (NHTiso) using Pearson’s correlation coefficient with 95% CI and limits of agreement. Bland-Altman plots were also created to provide a representation of the agreement between two test devices. Strong correlations, good ICC values and acceptable typical errors of the estimate were observed between the NHT and isokinetic strength testing (IST) during both limbs with no proportional bias for validity analysis. In conclusion, the “IVMES H-Bord” is a reliable and valid measurement device for eccentric hamstring muscle strength and it provides important advantages for medical staff, fitness coaches and practitioners because it is portable, low cost, and field-based assessment.

Target strength measurements of yellowfin tuna (Thunnus albacares) and acoustic discrimination of three tropical tuna species

Abstract Tropical tuna fisheries support some of the largest artisanal and industrial fisheries worldwide. Approximately 37% of the tropical tuna catch by industrial purse seiners is obtained from tuna associated with drifting fish aggregating devices (DFADs), where three tuna species coexist: skipjack (Katsuwonus pelamis), bigeye (Thunnus obesus), and yellowfin tuna (Thunnus albacares), with stocks subject to different health status. Purse seine fishers heavily rely on acoustic technology to detect and assess the quantity of tuna at DFADs. Yet, accurately distinguishing between species using solely acoustic methods is limited by insufficient knowledge about each species' acoustic response across frequencies. This study was carried out on six swimbladdered individuals belonging to two sets with mean lengths of 51.9 ± 9.5 and 52.9 ± 2 cm. It focuses on the frequency response obtained from ex situ measurements of yellowfin tuna recorded at 38, 70, 120, and 200 kHz, which revealed a flat response across frequencies, with b20 values of −72.4 ± 9, −73.2 ± 8, -72.3 ± 8, and −72.3 ± 9 dB, respectively. These results, contrast with previous findings on bigeye and skipjack, demonstrating the discrimination potential of acoustics in these three species. To harness this potential, a discrimination algorithm was developed.

MODELLING THE STRUCTURAL PARAMETERS OF THE GLUE COMPOSITION AND STUDYING ITS ADHESIVE STRENGTH

The study considers a model of a filled polymer system to analyse the interaction and relationship between its components and adhesive properties. A two-phase system occurs in the filler composition, which forms a layer at the interface with properties different from the bulk properties of the filler and the binder. The system consists of a filler, a boundary layer, and a binder, with their properties accounted for with the accuracy of the manufacturing conditions and the dimensions of the sample. We found that the filler grains shape significantly affects the properties of the system, such as bond strength and water resistance. Distance analysis between filler particles showed that a decrease in its volume fraction in the composition leads to an increased distance between them. We can draw the most objective conclusions after processing the filler particles since, in this case, everything depends on the change of interactions at the boundary (the properties of the matrix in the volume practically do not change). In other cases (for example, in the case of changing the temperature and time conditions of preparation and testing), not only the surface but also the volume properties of the matrix change, and, accordingly, it is usually impossible to conclude the role of adhesion. Its processes are part of the adhesion strength of the adhesive material, so the adhesion strength (also called interfacial strength, boundary strength, and bond strength) has been the subject of constant research for several decades. Adhesion strength is a quantitative indicator of adhesion, i.e., a quantitative indicator of the adhesion forces between the polymer matrix and the dispersed filler as a substrate. While the wetting angle of the edge characterises the process of formation of an adhesive bond, the strength of adhesion characterises the process of its destruction. Knowing the limits of the ‘ideal’ adhesion region can answer the question of what limits to aim for to improve adhesion, but this requires practical measurement of the interfacial strength between the acrylic composition and the filler, which is challenging. As a result, the strength of the composite can be a monotonically increasing function of the adhesion strength, but only in a limited range of values. An increase in adhesion can lead to a decrease in the strength of the adhesive material, depending on the size of the filler particles and the volume fraction of the filler. Adhesion strength is a quantitative indicator of the adhesion strength between the polymer matrix and the dispersed filler. The strength of adhesion affects the strength of the composite material. The ideal adhesion strength depends on the size and volume fraction of the filler. Excessive adhesion strength can lead to a decrease in the strength of the adhesive material. Keywords: polymer-mineral composition, adhesion, cohesion, acrylic glue.

Synergistic enhancement of dielectric strength and thermal conductivity in meta-aramid-based composite films via honeycomb cavities filling strategy

Owning superior dielectric and mechanical properties, poly (m-phenylene isophthalamide) (PMIA) fiber is an ideal insulation material for next-generation electric and electronic devices. However, its low thermal conductivity poses a risk of thermal breakdown. Moreover, PMIA films prepared using the unique protonation method exhibit a honeycomb-like structure with numerous air pockets, further reducing heat transfer efficiency. Herein, we propose a strategy of honeycomb cavities filling to synergistically improving the dielectric strength and thermal conductivity of PMIA-based composite films. To achieve a denser configuration, the nanodiamond (ND) fillers modified by polydopamine (PDA) are uniformly filled in the cavities within the PMIA skeleton, serving as thermally conductive reinforcements. In the 15 wt% composite film, the breakdown strength and thermal conductivity measure 334 kV/mm and 1.12 W/(m·K), respectively, which are 42.3 % and 833 % higher than that of the pure one. Furthermore, the underlying mechanisms are studied based on density functional theory and multi-physics simulations.

Predicting the Fracture Toughness of Human Cancellous Bone in Fractured Neck of Femur Patients Using Bone Volume and Micro-Architecture.

The current protocol used to determine if an individual is osteoporotic relies on assessment of the individual's bone mineral density (BMD), which allows clinicians to judge the condition of a patient with respect to their peers. This, in essence, evaluates a person's fracture risk, because BMD is a good surrogate measure for strength and stiffness. In recent studies, the authors were the first to produce fracture toughness (FT) data from osteoporotic (OP) and osteoarthritic (OA) patients, by using a testing technique which basically analyzes the prerequisite stress conditions for the onset of growth of a major crack through cancellous bone tissue. FT depends mainly on bone quantity (BV/TV, bone volume/tissue volume), but also on bone micro-architecture (mArch), the inner trabecular design of the bone. The working research hypothesis of the present study is that mArch offers added prediction power to BV/TV in determining FT parameters. Consequently, our aim was to investigate the use of predictive models for fracture toughness and also to investigate if there are any significant differences between the models produced from samples loaded across (AC, transverse to) the main trabecular orientation and along (AL, in parallel) the trabeculae. In multilinear regression analysis, we found that the strength of the relationships varied for a crack growing in these two orthogonal directions. Adding mArch variables in the Ac direction helped to increase the R2 to 0.798. However, in the AL direction, adding the mArch parameters did not add any predictive power to using BV/TV alone; BV/TV on its own could produce R2 = 0.730. The present results also imply that the anisotropic layout of the trabeculae makes it more difficult for a major crack to grow transversely across them. Cancellous bone models and remodels itself in a certain way to resist fracture in a specific direction, and thus, we should be mindful that architectural quality as well as bone quantity are needed to understand the resistance to fracture.

Predictors of Hand Grip Strength in Adults Without Sarcopenia: Data From the NHANES, 2013–2014

BackgroundGrip strength measurement is used to estimate muscle strength and predict health status; yet, an accurate examination of grip strength predictors from body composition variable is lacking. ObjectivesThis study aimed to examine the association of grip strength with lumbar bone mineral density (BMD) and total lean mass in adults without sarcopenia. MethodsAdults without sarcopenia (N = 3100) were included from the NHANES, 2013–2014, in this cross-sectional study. Body mass (kg), body height (cm), body mass index (kg/m2), grip strength (kg), total percent fat (%), lumbar BMD (g/cm2), and total lean mass excluding bone mineral content (BMC, kg) were obtained and tested as predictors of grip strength. ResultsThe regression analysis yielded a significant model [F(2,343732) = 71,284.2; R2 = 0.713; P < 0.001], with all predictors explaining ∼71.3% of the variance in grip strength. Age [β: −0.043; 95% confidence interval (CI): −0.040, −0.036], sex (β: −0.296; 95% CI: −6.431, −6.270), total percent fat (β: −0.245; 95% CI: −0.315, −0.308), lumbar BMD (β: 0.037; 95% CI: 2.529, 2.806), and total lean mass (β: 0.482; 95% CI: 0.001, 0.001) were all significant predictors of grip strength. ConclusionsThe predictive value of the BMD and total lean mass can serve as a useful measure in predicting grip strength and overall health status in adults without sarcopenia.