Designing wearable computing devices for improved comfort and user acceptance.

This study identified acceptable range of physical attributes (form factors, weight, volume and contact area) of wearable computing devices (WCD) on different body areas in relation to human factors, through human performance tests with 41participants. Findings of this study discovered that there is a different level of threshold to discomfort on each part of the body; forearm has the smallest estimated mean of acceptable maximum weight of WCD followed by shirt pocket and collar area. On the other hand, front waist and back waist, when placed on one side, showed significantly higher estimated means of acceptable maximum weight of WCD than any other areas. Similar data trend was found in acceptable maximum volume and contact area of WCD. Body movement and posture influence the users' comfort, as the weight of WCD can cause unhealthy posture over time, and increased energy expenditure, which may cause orthopaedic problems and discomfort. Practitioner summary: This study discovered that in carrying wearable computing devices (WCD), there is a different level of threshold to discomfort on each part of the body, as evidenced by significantly different acceptable maximum weight, volume and contact area of WCD on different body part. Abbreviations: WCD: wearable computing devices.

Fit of fire boots: exploring internal morphology using computed tomography.

Fit of fire boots is a crucial factor in the safety and performance of firefighters on the hostile fireground. Firefighters have reported that ill-fitting fire boots restrict their lower body movement and sometimes cause very dangerous situations by falling off behind the wearer. By using computed tomography, this study demonstrates the potential to quantify and visualize the fit of fire boots, which previously relied on subjective feedback from the wearers. The high-resolution three-dimensional (3D) models of two fire boot products allowed a detailed observation and measurement of the internal space of the boots. Also, the boot's internal dimension was compared to the foot measurement of local firefighters, showing the significant differences between the two boots. Lastly, simulation wrapping the 3D scanned foot with the boot revealed large void spaces around the toe box and ankle, as well as the narrower ball width of the boot than the foot.

Electrochemical recovery of nutrients from human urine coupled with biogas upgrading.

This study explored the coupling of electrochemical nutrient recovery from human urine with biogas upgrading. Ammonia nitrogen-rich (≥300 mM) and alkaline (≥pH 9) hydrolyzed urine (HU) is a promising alternative CO2 solvent. Spent urine after biogas upgrading (SU), with neutralized pH and increased conductivity resulting from CO2 absorption, is advantageous over HU for recovering total ammonia nitrogen (TAN) through electro-concentration. Experiments using synthetic urine at varying applied current densities (13-77 A/m2) demonstrated effective TAN recovery from both HU and SU, with greater enrichment factors at higher currents (2.1-3.3-fold, 1.2-1.8 M TAN concentrate). Validation experiments using real urine at the optimized current density of 52 A/m2, considering energy consumption, exhibited superior TAN recovery and energy efficiency when using SU (3.7-fold enrichment, 1.6 M TAN concentrate; suitable for liquid fertilizer) compared to HU. These findings offer an advanced strategy for maximizing urine valorization, contributing to a circular economy.

Impact of ballistic body armour and load carriage on walking patterns and perceived comfort.

This study investigated the impact of weight magnitude and distribution of body armour and carrying loads on military personnel's walking patterns and comfort perceptions. Spatio-temporal parameters of walking, plantar pressure and contact area were measured while seven healthy male right-handed military students wore seven different garments of varying weight (0.06, 9, 18 and 27 kg) and load distribution (balanced and unbalanced, on the front and back torso). Higher weight increased the foot contact time with the floor. In particular, weight placement on the non-dominant side of the front torso resulted in the greatest stance phase and double support. Increased plantar pressure and contact area observed during heavier loads entail increased impact forces, which can cause overuse injuries and foot blisters. Participants reported increasingly disagreeable pressure and strain in the shoulder, neck and lower back during heavier weight conditions and unnatural walking while wearing unbalanced weight distributed loads. This study shows the potentially synergistic impact of wearing body armour vest with differential loads on body movement and comfort perception. PRACTITIONER SUMMARY: This study found that soldiers should balance loads, avoiding load placement on the non-dominant side front torso, thus minimising mobility restriction and potential injury risk. Implications for armour vest design modifications can also be found in the results.

Firefighters' feet: Differences by sex and weight-bearing.

Firefighters have reported their protective boots to be bulky and ill-fitting, which they believe restrict the lower body movement on the unpredictable fireground. This study used 3D foot scanning to compare the shape of firefighters' feet to the general population, the shape of female firefighters' feet to males, and the impact of the heavy fire gear on foot shape. The results found the foot breadth of firefighters was larger than the general population and the feet of female firefighters were slimmer than males. Furthermore, it revealed that the feet of firefighters became longer, wider, and flatter when bearing the weight of fire gear. Protective boots should be designed based on the foot shape and dimensions of the actual population, with consideration of sex differences and the impact of weight-bearing for their safety.

Effects of load carriage and work boots on lower limb kinematics of industrial workers.

Load and footwear condition are two crucial elements varying the kinematic responses during walking, which probably lead to chronic injury. Fifteen healthy male individuals with no obvious gait abnormalities participated in this study. Apart from a no-load condition, four external load conditions with two load levels were investigated. Work boots were compared with running shoes to determine footwear effects. Significant impacts were found for lower limb range of motion at certain joints when carrying loads. A greater hip and ankle flexion-extension while wearing the work boots indicated that participants needed to lift the leg higher to complete toe clearance off the walking surface. Work boots also increased the vertical excursion of the center of body mass, which may impact body balance and induce falling. No significant influencing pattern of carrying modes was found, which was probably due to the light load and relatively stable mode of shoulder carrying.

Impact of work boots and load carriage on the gait of oil rig workers.

Effects of work boots and load carriage (6.4 kg and 12.8 kg) on gait pattern were investigated. The protective work boots were examined by comparison with running shoes through human performance tests with 15 male participants. The loads were carried symmetrically and asymmetrically on the shoulder and hand. Statistical data analysis showed a prolonged stance phase and decreased double support for work boots. A significantly increased ground reaction force was found in work boot conditions as the weight of loads increases. This study demonstrates that inflexible and heavy work boots restrict foot movement and require greater torque at the ankle to propel the body forward, which may increase physical strain and the risk of musculoskeletal injuries. Development of improved fixation methods for work boots, increased use of flexible protective layers and further study of anthropometry of human foot morphology for improved safety and work efficiency of industry workers are suggested.

Effect of firefighters' personal protective equipment on gait.

The biomechanical experiment with eight male and four female firefighters demonstrates that the effect of adding essential equipment: turnout ensemble, self-contained breathing apparatus, and boots (leather and rubber boots), significantly restricts foot pronation. This finding is supported by a decrease in anterior-posterior and medial-lateral excursion of center of plantar pressure (COP) trajectory during walking. The accumulation of this equipment decreases COP velocity and increases foot-ground contact time and stride time, indicating increased gait instability. An increase in the flexing resistance of the boots is the major contributor to restricted foot pronation and gait instability as evidenced by the greater decrease in excursion of COP in leather boots (greater flexing resistance) than in rubber boots (lower resistance). The leather boots also shows the greatest increase in foot contact time and stride time. These negative impacts can increase musculoskeletal injuries in unfavorable fire ground environments.

Efficient, Solvent-Free, Multicomponent Method for Organic-Base-Catalyzed Synthesis of ß-Phosphonomalonates.

An efficient, one-pot, di-n-butylamine-catalyzed, three-component synthesis of ß-phosphonomalonates has been developed. A wide range of substrates, including aromatic and fused aromatic aldehydes, were condensed with enolizable C-H activated compounds and dialkylphosphites to give the desired products in excellent yields. This method provides an eco-friendly alternative approach to rapid construction of a diversity-oriented library of ß-phosphonomalonates.

Poly(PEGA)-b-poly(L-lysine)-b-poly(L-histidine) Hybrid Vesicles for Tumoral pH-Triggered Intracellular Delivery of Doxorubicin Hydrochloride.

A series of poly(ethylene glycol) methyl ether acrylate-block-poly(L-lysine)-block-poly(L-histidine) [p(PEGA)30-b-p(Lys)25-b-p(His)n] (n = 25, 50, 75, 100) triblock copolypeptides were designed and synthesized for tumoral pH-responsive intracellular release of anticancer drug doxorubicin hydrochloride (Dox). The tumoral acidic pH-responsive hybrid vesicles fabricated were stable at physiological pH 7.4 and could gradually destabilize in acidic pH as a result of pH-induced swelling of the p(His) block. The blank vesicles were nontoxic over a wide concentration range (0.01-100 µg/mL) in normal cell lines. The tumor acidic pH responsiveness of these vesicles was exploited for intracellular delivery of Dox. Vesicles efficiently encapsulated Dox, and pH-induced destabilization resulted in the controlled and sustained release of Dox in CT26 murine cancer cells, and dose-dependent cytotoxicity. The tumor-specific controlled release Dox from vesicles demonstrates this system represents a promising theranostic agent for tumor-targeted delivery.

What do firefighters desire from the next generation of personal protective equipment? Outcomes from an international survey.

The purpose of this study was to investigate smart features required for the next generation of personal protective equipment (PPE) for firefighters in Australia, Korea, Japan, and the USA. Questionnaire responses were obtained from 167 Australian, 351 Japanese, 413 Korean, and 763 U.S. firefighters (1,611 males and 61 females). Preferences concerning smart features varied among countries, with 27% of Korean and 30% of U.S. firefighters identifying 'a location monitoring system' as the most important element. On the other hand, 43% of Japanese firefighters preferred 'an automatic body cooling system' while 21% of the Australian firefighters selected equally 'an automatic body cooling system' and 'a wireless communication system'. When asked to rank these elements in descending priority, responses across these countries were very similar with the following items ranked highest: 'a location monitoring system', 'an automatic body cooling system', 'a wireless communication system', and 'a vision support system'. The least preferred elements were 'an automatic body warming system' and 'a voice recording system'. No preferential relationship was apparent for age, work experience, gender or anthropometric characteristics. These results have implications for the development of the next generation of PPE along with the international standardisation of the smart PPE.

Folic acid-tethered poly(N-isopropylacrylamide)-phospholipid hybrid nanocarriers for targeted drug delivery.

A series of temperature-responsive lipopolymers have been synthesized by bioconjugating poly(N-isopropylacrylamide)n (n = 25, 40, 60) onto three different phospholipids by the combination of reversible addition fragmentation chain transfer polymerization and azide-alkyne click reactions. To achieve the active targeting of cancer cells, folic acid (FA) has also been tethered to the resulting hybrid materials. The doxorubicin (Dox) encapsulated uniform nanocarriers (150 nm in diameter) fabricated by the self-assembly of the lipopolymers display temperature responsive controlled release. The FA receptor-mediated delivery of Dox was then assessed using KB cell lines, and the anti-cancer activity was assessed by the blocking of folic acid receptors. The FA-tethered lipopolymers showing temperature-responsiveness are advantageous for the cell-specific release of Dox, potentiating their anti-cancer activity.

Effect of armor and carrying load on body balance and leg muscle function.

This study investigated the impact of weight and weight distribution of body armor and load carriage on static body balance and leg muscle function. A series of human performance tests were conducted with seven male, healthy, right-handed military students in seven garment conditions with varying weight and weight distributions. Static body balance was assessed by analyzing the trajectory of center of plantar pressure and symmetry of weight bearing in the feet. Leg muscle functions were assessed by analyzing the peak electromyography amplitude of four selected leg muscles during walking. Results of this study showed that uneven weight distribution of garment and load beyond an additional 9 kg impaired static body balance as evidenced by increased sway of center of plantar pressure and asymmetry of weight bearing in the feet. Added weight on non-dominant side of the body created greater impediment to static balance. Increased garment weight also elevated peak EMG amplitude in the rectus femoris to maintain body balance and in the medial gastrocnemius to increase propulsive force. Negative impacts on balance and leg muscle function with increased carrying loads, particularly with an uneven weight distribution, should be stressed to soldiers, designers, and sports enthusiasts.