Physical Load Research Articles

Cell size and deformation measurement using constrictions integrated into a microfluidic device

In this study, we developed a microfluidic device to evaluate cell size and deformability. As a specific method, a physical pushing load was applied to the cells using a channel having a constriction with a height of 1 μm. In addition, by orienting the constriction in a vertical direction, it was possible to measure the cell area easily using a microscope under load. The system constructed in this study can evaluate the contact area between the cells and the glass surface before and after applying a load under a microscope. The only input parameter was the syringe flow rate, and it was possible to evaluate multiple cells in a cell suspension simultaneously. Also, since the flow rate is 50 μm min−1 or less, there is no need for a high-speed camera. This time, we evaluated cell types with different characteristics: NIH/3T3 and smooth muscle cells (SMC). To evaluate deformability, we focused on the circularity of the cells during load application. Due to the influence of the flow within the channel, cells with high deformability assumed an almost elliptical shape and flowed through the constriction. Using the device developed in this study, we confirmed that SMCs, which are muscle cells, have large variations in cell size and hardness among individual cells. Finally, we discussed these results and possible future applications.

Pluronic L121-Chrysin conjugated polymeric micelles of exemestane: Improved synergistic effect, in vitro and in vivo anticancer activity

Hormonal imbalances, particularly those involving estrogen and progesterone, are strongly associated with the development of breast cancer. Exemestane, an irreversible aromatase inhibitor, is used to treat estrogen-positive breast cancer. However, its clinical effectiveness is hampered by poor water solubility and bioavailability. Additionally, relying solely on a single chemotherapeutic agent often leads to poor therapeutic outcomes. Thus, there is a growing interest in the co-delivery of anticancer drugs, especially those of natural origin. In this study, our aim was to develop and optimize micelles for the simultaneous delivery of Exemestane and Chrysin. Exemestane was incorporated into mixed micelles via physical loading, while chrysin was linked to Pluronic L121 to create CHS-L121. Employing the Box-Benken design of experiments, we investigated the impact of polymer concentration on the independent variable. The optimized mixed micelles exhibited a particle size of 33.04 ± 2.62 nm and a polydispersity index of 0.145 ± 0.02. Notably, these micelles demonstrated excellent drug loading (5.2±2.2 %) and entrapment efficiency (89.6±2.5 %). In addition, CHS-EXE-MMs exhibited significant cytotoxicity against the MCF-7 cell line and showed enhanced in vivo anticancer activity in BALB/c mice. In vivo pharmacokinetic studies further revealed improved bioavailability of EXE and CHS through micelles. Our findings highlight the potential of CHS-EXE-MMs as a promising approach in breast cancer therapy.

Pathological Turbulence of the Heart Rhythm and Activation of the Antinociceptive System as Predictors of the Complicated Course of Silent Myocardial Ischemia in Patients with Post Infarction Cardiosclerosis According to the Data of Long-term Observation

To date, the issues of evaluating the course of silent myocardial ischemia (SMI) after a myocardial infarction (MI) taking into account risk factors (RF), evaluating the pathological turbulence of the heart rhythm, the state of activation of the body’s antinociceptive system, which necessitates an in-depth study of this pathology, remain unresolved, as well as new differentiated approaches to the treatment and rehabilitation of the modern category of patients. The objective: to analyze the features of the SMI course in patients with post-infarction cardiosclerosis depending on the RF. Identification of the interdependence between the degree of activation of the sympathoadrenal system and the features of the SMI course in patients with post-infarction cardiosclerosis, as well as the prognostic value for assessing the severity of the course of the disease. Materials and methods. The research was performed on the basis of the Ivano-Frankivsk Regional Clinical Cardiology Center (Ukraine). 154 patients with a silent form of coronary artery disease, which occurred in people with post-infarction cardiosclerosis, were examined. The diagnostic criteria were: episodes of SMI verified with the help of HM ECG and a test with dosed physical load. Results. Significant deviation of the ST segment which was detected during Holter monitoring of the ECG (HM ECG) in patients with SMI episodes does not mean that the absence of pain sensations in the presence of efferent nociceptive stimulation is a sign of the absence of ischemia and does not indicate an easier course of SMI compared to clinically manifest forms of CHD. The average concentration of β-endorphins in patients with lipid metabolism disorders was 4.01±0.02 ng/ml, in the presence of diabetes mellitus this indicator was equal to 4.68±0.03 ng/ml (р<0.01), and in persons with concomitant arterial hypertension it was 4.91±0.02 ng/ml (р<0.05). In subjects with two or more RFs, the similar indicator was the highest and amounted to 5.73±0.03 ng/ml (р<0.01). The point-biserial correlation coefficient was equal to 0.61 (р<0.05), which indicates a sufficiently high probability of the influence of the processes of activation of the antinociceptive system on the risk of myocardial infarction and unstable angina. Conclusions. It has been proven that the presence of postinfarction cardiosclerosis, type 2 diabetes mellitus, dyslipidemia, and arterial hypertension should be considered as factors that increase the risk of complications of coronary artery disease in patients with SMI. In the painless form of CHD, there is a probable increase in β-endorphins in the blood, which indicates the presence of pronounced afferent nociceptive stimulation, the intensity of which depends on the degree of myocardial ischemia. It has been proven that an increase of β-endorphins levels is associated with an increase in the risk of a complicated course of coronary heart disease in patients with silent myocardial ischemia. The presence in patients with SMI of myocardial ischemia, pathological turbulence of the heart rhythm, and activation of the antinociceptive system are extremely important for understanding the main links of the course of SMI and make it possible to base the approach to the therapy of such patients on a differentiated system algorithm that takes into account the discrepancy between the clinical manifestations of the disease and its real impact on coronary perfusion and the condition of the vascular wall.

Nursing students' self-esteem levels and attitudes toward the nursing profession.

This study aimed to examine nursing students' self-esteem levels and attitudes toward the nursing profession. Although it is important to choose a profession that will make the person happy in many aspects such as one's abilities, interests, values, attitudes, personal goals, and social expectations, it has an important place, especially in a profession such as nursing, which involves intense emotional and physical load. The study population was 390 nursing students at a foundation university in Istanbul, while the sample included 202 students. Data were collected between January 16, 2023, and February 15, 2023, with the Demographic Data Collection Tool, Coopersmith Self-Esteem Inventory, and the Attitude Scale for Nursing Profession. The data were analyzed using the SPSS 27.0 program. The STROBE checklist was used to report the study. The mean age of the participants was 20.79±1.72 (years), among which 65.3% were in the 20-22 age range, 76.7% were female, and 29.7% were in the first grade. A positive but very weak relationship was found between the Coopersmith Self-Esteem Inventory and the Attitude Scale for Nursing Profession scores (p<0.05). The results show that professionalization and socialization processes greatly affect nursing students' self-esteem. Considering the extended period that students spend in academic institutions under the guidance of faculty members, this matter deserves greater attention. While developing the curriculum and education process, factors that support the development of self-esteem in nursing students should be taken into account and initiatives should be planned to increase positive attitudes toward the profession. Nursing students can gain different perspectives by spending more time with nurses in hospitals.

Kinematic and Physiological Analysis of Medieval Combat Sport Using Motion Analysis, Blood Lactate Measurement, and Heart Rate Monitoring: A Case Study.

Medieval combat sport is a form of mixed martial art in which combatants engage in fighting using offensive and defensive equipment while dressed in full armor. The sport is considered extremely taxing, making it nearly impossible to maintain the same level of performance. However, this form of sport has not been thoroughly analyzed, and its impact on human physical response is largely unknown. To address this gap, the study reported here aimed to introduce and test a procedure for analyzing human physical responses within the framework of the sport. To accomplish this, two experienced combatants were asked to engage in a series of strikes, performed in the form of a set duel simulating a professional fight competition. The kinematic aspect of the procedure was examined using motion analysis with the help of an IMU suit, while the physiological aspect was evaluated based on blood lactate levels and heart rate measurements. Furthermore, an ergometer test conducted in a laboratory setting aimed to determine the lactate threshold. The duel results showed noticeable decreases in the kinematic aspects of the strikes, such as the velocity of impact, and a dramatic rise in physiological aspects, such as heart rate and blood lactate levels. During the duel sets, the blood lactate surpassed the threshold level, and at the end, the heart rate exceeded the maximum age-related level. Practicing medieval combat sport has been shown to impose an extreme physical load on the bodies of combatants, noticeably affecting their performance levels.

A Case Study of Ergonomic Risk Assessment in Slovakia with Respect to EU Standard.

Attention on work-related musculoskeletal disorders (WMSDs) involves statistical surveys showing an increasing trend in the incidence of WMSDs. Technological development has led to new tools and methods for the assessment of physical load at work. These methods are mostly based on the direct sensing of appropriate parameters, which allows more precise quantification. The aim of this paper is to compare several commonly used methods in Slovakia for the assessment of ergonomic risk reflecting current EU and Slovak legislative regulations. A Captiv wireless sensory system was used at a car headlight quality control assembly workplace for sensing, data acquisition and data processing. During the evaluation of postures and movements at work, we discovered differences in the applicable standards: Decree 542/2007 Coll. (Slovak Legislation), the STN EN 1005-4+A1, and the French standards default in the Captiv system. Standards define the thresholds for hazardous postures with significant differences in several evaluated body segments, which affects the final evaluation of the measurements. Our experience from applying improved risk assessment methodology may have an impact on Slovak industrial workplaces. It was confirmed that there is a need to create uniform standards for the ergonomic risk assessment of body posture, including a detailed description of the threshold values for individual body segments.

Risk assessment of healthcare workers’ exposure to physical load in relation to patient handling and movement: a feasibility study of the instrument TilThermometer

BackgroundWork-related musculoskeletal disorders are common among healthcare workers (HCWs) but might be prevented by risk assessment and further promotion of occupational safety and health.The aim of this study was to investigate if the risk assessment instrument TilThermometer can be used to identify risk profiles of physical exposure in HCWs working with patient handling and movement (PHM). Further aims were to describe HCWs’ perceptions and experiences of using the TilThermometer.MethodsThis feasibility study has a mixed design methodology. In total, 54 HCWs from 17 Swedish care units participated and performed risk assessments with the TilThermometer. Data collected from the risk assessments were used to identify risk profiles of physical exposure. HCWs’ experiences of using the TilThermometer were collected from activity logs and analysed qualitatively. Three questionnaires were used to assess perceived acceptability, appropriateness, and feasibility of the risk assessment, and eight study specific questions were used for perceived usefulness.ResultsThe TilThermometer was used at the care units by assessing each care recipient, and when compiling the data at a group level, a summarized risk profile for the care unit could be provided. Risk for physical exposure was reported as high in two work tasks; no care unit used the high-low adjustable seat when showering care recipients sitting down, and 13% used the recommended assistive devices when putting compression stockings on. However, 99% used high-low adjustable assistive devices when caring and bathing care recipients lying down. TilThermometer was described as easy to use, enabling team reflections and providing an overview of the care units’ recipients and workload, but difficulties in categorizing for mobility groups were also reported. The TilThermometer was, on a five-point scale, perceived as acceptable (mean 3.93), appropriate (mean 3.9), and feasible (mean 3.97). These scores are in line with questions evaluating usefulness.ConclusionThe risk assessment provided risk profiles with potential to contribute to care units’ development of a safe patient handling and movement practice. The findings suggest that the TilThermometer can be used to assess risks for physical exposure in relation to patient handling and movement in care units at hospital and nursing homes.

Formation of stulents' skills to use physical culture through awareness of the features of endurance development

The purpose of the study was to clarify the views of the authors on the peculiarities of the development of endurance and the formation of students' awareness of such peculiarities in the process of physical education classes. The subject discussion of the work is the disclosure of the need to consciously use the knowledge of the development of various physical abilities in the areas of sports, health and vocational training as the key foundations of the students' conscious perception of the features of using physical exercises. Carrying out work tasks through the analysis of pedagogical literature, literature on physical culture and information from the Internet about the main features of the development of endurance through the use of physical exercises in sports, health and vocational training makes it possible to direct the educational directions of familiarizing students with the characteristics of training processes, enriching conscious experience use of means of physical culture. Such aspects should be considered the novelty of the research. The conclusions point to the understanding of the contents defined by the topic, emphasize the views on the relevance of introducing into the educational process of practical physical education aspects of the activation of students' conscious perception of methodical features of endurance development through the improvement of self-control skills, planning of physical load through the study of the limits of functional indicators under the influence of physical exercises.

Female Wrestling: The Finger Index «2d:4d» Of Female Athletes

Aim of study The aim of this article is to present and analyze the research conducted to identify the changes in the values of finger index 2D:4D, in a group of female athletes, intensively and professionally engaged in such types of martial arts as pankration and judo wrestling and pancration. Hypothesis of the study The hypothesis of this study is that female athletes with mesomorphic and andromorphic sex somatotypes, and values of finger index 2D:4D, male type, will have better sports results when practicing their sports - judo wrestling and pankration, which is due to the medical and biological restructuring of their body, under the influence of intense physical and psycho-emotional loads.

Physical and Physiological Demands of Amateur Portuguese Field and Assistant Football Referees.

Referees are crucial elements in football, and they must meet the physical and physiological demands each match poses to them. The aim is to analyse the physical and physiological demands of amateur referees in games at the regional level (4th division), examining the differences between the first and second halves and between assistant (age: 25.10 ± 4.97) and main referees (age: 25.65 ± 5.12). A total of 29 matches were analysed with GPS devices, and internal and external load metrics were analysed. Overall, main referees, due to their central role in game management, showed higher levels of physical and physiological load than assistant referees, with more high-intensity activities, greater distance covered and higher heart rate. The results also revealed that there were no differences between the halves for total distance covered for either the main or assistant referees. However, the main referees covered a greater distance in high-intensity running during the first half (p = 0.05; d = 0.389). These findings emphasise the importance of tailored training protocols to enhance performance and reduce fatigue-related errors, highlighting the significance of endurance, high-intensity running ability, and strategies to manage transient fatigue in referee preparation.

DEPENDENCE OF OXIDATIVE BALANCE AND CHOLESTEROL METABOLISM IN MUSCLE TISSUE ON EXERCISE INTENSITY

Intriduction. Changes in oxidative balance and lipid metabolism have the leading role in performance limitation, adaptation and maladaptation to physical activity. It is especially important to analyse the direction of metabolic changes at the subcellular level. The aim of the study is to examine the state of oxidative balance and cholesterol metabolism in muscle tissue at moderate and maximal swim-ming load. Material and methods. A comprehensive study of indicators for free-radical oxidation (content of diene conjugates, TBA-active products, chemilu-minescence intensity), antioxidant defense (total antioxidant activity, antiradical activity) and cholesterol metabolism in tissues of heart muscle and thigh muscle of white male rats at moderate and maximum swimming load was carried out. Results. The patterns of metabolic changes in muscle tissue depending on the intensity of muscular work have been established: these are the forms of compensated oxidative stress at moderate and decompensated at maximum load, against the background of decreasing cholesterol content. In cardiac tissue oxidative stress phenomena were less expressed, and changes in cholesterol content were multidirectional: a tendency to decrease at moderate load and a significant increase at maximum load. Conclusion. The reduction of antioxidant defence resources and intensification of free-radical oxidation reactions constitute one of the leading mecha-nisms for metabolic disorders due to extreme physical load, which is confirmed by reliable changes in the studied parameters. The complex study of indicators characterizing the processes of free-radical oxidation, antioxidant protection and cholesterol content is an informative criterion for the influ-ence of physical exercise on the organism. The obtained data allow us to recommend the inclusion of antioxidants in the complex prevention and ther-apy of acute physical overstrain.

Using Heart Rate Variability to Assess Nurses' Stress During the COVID-19 Pandemic.

This study aimed to assess subjective and objective parameters of stress among nurses during the COVID-19 pandemic and to examine the recovery effect of a day off. In this prospective observational trial, we measured heart rate variability (using a wearable device) and perceived stress levels on 3 working days and 1 day off. We obtained the following data using an online questionnaire: working conditions, COVID-19-related problems, depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder-7), effort-reward imbalance, and work-family conflict in a sample of German nurses (N = 41). When comparing working days with a day off, we observed a significant difference for physical load (Cohen's d = 0.798, P < .001), mental load (Cohen's d = 0.660, P = .001), emotional exhaustion (Cohen's d = 0.945, P < .001), and overburdening (Cohen's d = 0.585, P = .002) with higher scores on working days. Regarding heart rate variability, we did not find a difference. Correlational analyses revealed a significant association between being afraid to get infected with COVID-19 and lower heart rate variability (r = -0.336, P = .045) and between being afraid to infect relatives and lower heart rate variability (r = -0.442, P = .007). Furthermore, a higher total sum score of work-family conflict was significantly associated with lower heart rate variability (r = -0.424, P = .01). As heart rate variability observations were different from those regarding subjectively perceived stress, further studies are needed to evaluate and differentiate the influence of work stress and other types of stress on heart rate variability.

Energy intake, hydration status, and sleep of world-class male archers during competition.

Nutritional intake and sleep, play an important role for recovery and performance in elite sport but little work has been undertaken in archery. The present study aimed to assess energy intake (EI), hydration status, and sleep parameters in world-class male archers over the course of a four-day competition. Results, Conclusions Six male, elite-standard archers participated in the study and measurements of hydration status, EI, competition load, and sleep were recorded throughout each day of competition. Daily energy, carbohydrate, and protein intake ranged between 2,563 and 3,986 kcal, 4 and 7.1 g/kg BM, 2.2 and 3.6 g/kg BM per day, respectively. Thus, archers practiced elements of periodized nutrition such that energy and carbohydrate intake was greater on the high-volume competition days (i.e. days 1 and 3; more numbers of arrows, longer duration, and walking distance) in comparison to low-volume days (days 2 and 4) over the tournament (all p > 0.01). Additionally, urine specific gravity was higher after waking, compared to pre- and post-competition, and before bed (all p < 0.05). This indicates that archers were euhydrated pre- and post-competition and before bedtime, while they were slightly hypohydrated after waking up. Sleep data show that disturbances were kept to a minimum. Collectively, archers appear capable of periodizing their nutritional intake according to daily physical loading during a tournament whilst, staying euhydrated and maintaining sleep quality. In part, such data can help to explain why these archers experience a sustained level of success.

UPRIGHT BIPEDAL EXERCISE TRAINING IMPROVES INTERVERTEBRAL DISC HEALTH: A SYSTEMATIC REVIEW AND META-ANALYSIS

INTRODUCTION &amp; AIMS The structure and function of human tissue, such as bone, muscle and tendon, can be improved with targeted exercise training. However, the effects of exercise training on intervertebral disc tissue has received comparably less attention. With a scope to identify types of exercise training that improve intervertebral disc health, this study examined the impact of historical exercise, sport and/or physical activity on quantitative intervertebral disc outcomes. METHODS The protocol was prospectively registered with PROSPERO (CRD42022366391). Five databases (inception to 30th September 2022), 17 trial registries and reference lists and forwards/backwards citations were searched. Inclusion criteria followed the Participants (human), Exposure (exercise, sport or physical activity for greater than one week), Comparators (non-exercise, sport or physical activity control group), Outcomes (magnetic resonance imaging measures of lumbar intervertebral disc health on a continuous scale [e.g. T2, signal intensity, intervertebral disc height]) and Study design (any) framework. Pairwise random-effects restricted maximum likelihood meta-analysis estimated standardised mean difference (Hedges g). RESULTS From the search yield of 2,150 records, 12 reports representing 10 studies (participants: 874) were deemed eligible. When compared to any comparator, upright bipedal exposures (g [95%CI]: 0.31 [0.06, 0.55]; P=0.014; studies: 6; participants: 346; I2: 87%), were associated with greater intervertebral disc health. However, no physical loading exposure (g [95%CI]: 0.29 [-0.23, 0.82]; P=0.275; studies: 10; participants: 874), non-upright/non-contact exposures (g [95%CI]: 0.70 [1.25, 2.64]; P=0.336; studies: 5; participants: 260), extreme trunk range of motion exposures (g [95%CI]: -0.28 [-1.60, 1.04]; P=0.456; studies: 3; participants: 230) and aerobic-based exposures (g [95%CI]: 0.48 [0.08, 1.04]; P=0.094) were associated. Sensitivity analyses supported the robustness of primary and secondary effect estimates. CONCLUSION Greater intervertebral disc health associated with a prior history of upright bipedal physical loading indicates prospective interventions examining upright bipedal exercise effects on intervertebral disc health are warranted.

High dose vitamin D supplementation decreases the risk of deficiency in male conscripts, but has no effect on physical performance-A randomized study.

Physical load during military training might increase the need for vitamin D; therefore, supplementation could be beneficial for 25(OH)D serum levels and physical performance. One hundred and twelvemale conscripts were randomized into two vitamin D oil capsule supplementation groups: 55 participants in the 600 IU group and 57 in the 4000 IU group with a follow-up period from July 2021 to May 2022. Physical fitness tests were performed in July, October and May. Hand grip strength tests were performed in July, October and January. Blood serum (25(OH)D), parathyroid hormone PTH), calciumand ionized calcium (i-Ca) values were measured in July, October, January and May. The 600 IU group had a lower (p < 0.001) value of 25(OH)D at all time points compared to the 4000 IU group, except at baseline. None of the subjects in the 600 IU group reached sufficient levels of 75 nmol/L of 25(OH)D in January and May. In May, 60% of participants in the 600 IU group and 30% in the 4000 IU group had 25(OH)D levels under 50 nmol/L. No significant differences in PTH or i-Ca values were found between the study groups at any time point. No significant differences at any time point were found in the physical fitness test or hand grip strength test between the groups. A 10-month vitamin D supplementation with 4000 IU decreased the incidence of vitamin D deficiency (<75 nmol/L) in young, male army conscripts during wintertime, but no differences in physical performance were found compared to 600 IU supplementation. Level I, Prospective randomized study.

Exploring Data Input Problems in Mixed Reality Environments: Proposal and Evaluation of Natural Interaction Techniques

Data input within mixed reality environments poses significant interaction challenges, notably in immersive visual analytics applications. This study assesses five numerical input techniques: three benchmark methods (Touch-Slider, Keyboard, Pinch-Slider) and two innovative multimodal techniques (Bimanual Scaling, Gesture and Voice). An experimental design was employed to compare these techniques’ input efficiency, accuracy, and user experience across varying precision and distance conditions. The findings reveal that multimodal techniques surpass slider methods in input efficiency yet are comparable to keyboards; the voice method excels in reducing cognitive load but falls short in accuracy; and the scaling method marginally leads in user satisfaction but imposes a higher physical load. Furthermore, this study outlines these techniques’ pros and cons and offers design guidelines and future research directions.

Pre-crastination across physical and cognitive tasks.

Pre-crastination refers to the tendency to begin a task as soon as possible, even at the cost of additional effort. This phenomenon is consistently observed in tasks in which participants are asked to select one of two buckets to carry to a target. Surprisingly, on a high proportion of trials participants choose the bucket that is closer to them (and further from the target) as opposed to the bucket that is further from them (and closer to the target). In other words, participants tend to complete the task of picking up a bucket as soon as possible, even when this requires additional physical effort. The purpose of the current experiment was to test whether an individual's tendency to pre-crastinate is stable across tasks. Participants performed a physical load task where they selected one of two buckets to carry to a target. The same participants performed a cognitive load task where they picked up number strings at one of the two bucket locations and mentally carried the number string to a target. We found that participants pre-crastinated in both tasks and this tendency was reduced as task difficulty increased. Importantly, we found a significant association between an individual's tendency to pre-crastinate in the physical load task and their tendency to pre-crastinate in the cognitive load task. Thus, an individual's tendency to pre-crastinate is consistent across tasks and suggests that this is a stable characteristic of how individuals choose to order tasks.

Study on Dynamic Response Characteristics of Offshore Floating Wind Turbine Pitch System

Due to its special working conditions, offshore wind turbine will bear large direct and indirect loads under the combined action of air flow and wave flow. In this paper, a variable pitch system composed of variablepitch motorand variable pitch bearing is improved, and the characteristics of system's bending moment, torque, vibration and other physical quantities under the action of multiple physical loads are verified, and the mechanical response characteristics of floating wind turbine under the control of unified variable pitch and independent variable pitch are studied under the running conditions at sea. The results show that mechanical structure of uniform pitch is compared with that of independent pitch, the independent variable pitch structure can effectively reduce the mean oscillation value of wind turbine tower in the parallel direction of air flow by optimizing control strategy, and reduce the thrust at the hub of wind turbine and the bending moment at the root of tower, but increase the vibration frequency and fatigue load of offshore wind turbine tower along parallel direction of air flow. Reduce the fatigue life of equipment. The research results can be used as a reference to reduce the variable pitch control and vibration suppression of offshore wind turbines and improve the reliability of wind turbines.

The mechanical effects of chemical stimuli on neurospheres.

The formulation of more accurate models to describe tissue mechanics necessitates the availability of tools and instruments that can precisely measure the mechanical response of tissues to physical loads and other stimuli. In this regard, neuroscience has trailed other life sciences owing to the unavailability of representative live tissue models and deficiency of experimentation tools. We previously addressed both challenges by employing a novel instrument called the cantilevered-capillary force apparatus (CCFA) to elucidate the mechanical properties of mouse neurospheres under compressive forces. The neurospheres were derived from murine stem cells, and our study was the first of its kind to investigate the viscoelasticity of living neural tissues in vitro. In the current study, we demonstrate the utility of theCCFA as a broadly applicable tool to evaluate tissue mechanics by quantifying the effect that oxidative stress has on the mechanical properties of neurospheres. We treated mouse neurospheres with non-cytotoxic levels of hydrogen peroxide and subsequently evaluated the storage and loss moduli of the tissues under compression and tension. We observed that the neurospheres exhibit viscoelasticity consistent with neural tissue and show that elastic modulus decreases with increasing size of the neurosphere. Our study yields insights for establishing rheological measurements as biomarkers by laying the groundwork for measurement techniques and showing that the influence of a particular treatment may be misinterpreted if the size dependence is ignored.

Lean and sustainability assessment in the sawmill industry using Sus-VSM: A case study in the context of Fiji

Waste from the perspective of lean manufacturing and sustainability has a huge influence on economic, environmental, and societal aspects. The inefficiency of the current manufacturing systems poses a huge risk to small and medium size sawmills going out of business as current prices of fossil fuel and associated emissions continue to rise at an alarming rate. In this case study, a local sawmill has been investigated to improve process efficiency using sustainable value stream mapping in the context of Fiji. The produced timber with the highest demand is selected as the product and a complete assessment is done on the downstream operation to compile data and develop the current state map. The current state map incorporates sustainability pillars to address the lacking factors such as energy and water consumption, raw material usage, labor physical load, and workspace noise level along with standard lean manufacturing time-based metrics. Sustainable value stream mapping allowed the research team along with a panel of experts to identify processor 2 as the root cause of bottlenecking, unnecessary material movement/transportation, and high physical load index score. Implementing a multi-blade horizontal bandsaw in place of processor 2 reduces; energy consumption for transport, energy consumption for processing, VAT, NVAT, process water consumption, raw material usage, and carbon emission by; 34.9%, 8.72%, 6.37%, 20%, 24.71%, 3.05%, and 10.33% respectively without compromising productivity. The findings of this research suggest evaluating and assessing sustainability performance using Sus-VSM in the sawmill industry unveils potential economic, environmental, and societal benefits.