Recent advances in photoelectrochemical hydrogen production using I-III-VI quantum dots.

Photoelectrochemical (PEC) water splitting, recognized for its potential in producing solar hydrogen through clean and sustainable methods, has gained considerable interest, particularly with the utilization of semiconductor nanocrystal quantum dots (QDs). This minireview focuses on recent advances in PEC hydrogen production using I-III-VI semiconductor QDs. The outstanding optical and electrical properties of I-III-VI QDs, which can be readily tuned by modifying their size, composition, and shape, along with an inherent non-toxic nature, make them highly promising for PEC applications. The performance of PEC devices using these QDs can be enhanced by various strategies, including ligand modification, defect engineering, doping, alloying, and core/shell heterostructure engineering. These approaches have notably improved the photocurrent densities for hydrogen production, achieving levels comparable to those of conventional heavy-metal-based counterparts. Finally, this review concludes by addressing the present challenges and future prospects of these QDs, underlining crucial steps for their practical applications in solar hydrogen production.

Revealing Two Distinct Formation Pathways of 2D Wurtzite-CdSe Nanocrystals Using In Situ X-Ray Scattering.

Understanding the mechanism underlying the formation of quantum-sized semiconductor nanocrystals is crucial for controlling their synthesis for a wide array of applications. However, most studies of 2D CdSe nanocrystals have relied predominantly on ex situ analyses, obscuring key intermediate stages and raising fundamental questions regarding their lateral shapes. Herein, the formation pathways of two distinct quantum-sized 2D wurtzite-CdSe nanocrystals - nanoribbons and nanosheets - by employing a comprehensive approach, combining in situ small-angle X-ray scattering techniques with various ex situ characterization methods is studied. Although both nanostructures share the same thickness of ≈1.4 nm, they display contrasting lateral dimensions. The findings reveal the pivotal role of Se precursor reactivity in determining two distinct synthesis pathways. Specifically, highly reactive precursors promote the formation of the nanocluster-lamellar assemblies, leading to the synthesis of 2D nanoribbons with elongated shapes. In contrast, mild precursors produce nanosheets from a tiny seed of 2D nuclei, and the lateral growth is regulated by chloride ions, rather than relying on nanocluster-lamellar assemblies or Cd(halide)2 -alkylamine templates, resulting in 2D nanocrystals with relatively shorter lengths. These findings significantly advance the understanding of the growth mechanism governing quantum-sized 2D semiconductor nanocrystals and offer valuable guidelines for their rational synthesis.

Provenance-Based Trust-Aware Requirements Engineering Framework for Self-Adaptive Systems.

With the development of artificial intelligence technology, systems that can actively adapt to their surroundings and cooperate with other systems have become increasingly important. One of the most important factors to consider during the process of cooperation among systems is trust. Trust is a social concept that assumes that cooperation with an object will produce positive results in the direction we intend. Our objectives are to propose a method for defining trust during the requirements engineering phase in the process of developing self-adaptive systems and to define the trust evidence models required to evaluate the defined trust at runtime. To achieve this objective, we propose in this study a provenance-based trust-aware requirement engineering framework for self-adaptive systems. The framework helps system engineers derive the user's requirements as a trust-aware goal model through analysis of the trust concept in the requirements engineering process. We also propose a provenance-based trust evidence model to evaluate trust and provide a method for defining this model for the target domain. Through the proposed framework, a system engineer can treat trust as a factor emerging from the requirements engineering phase for the self-adaptive system and understand the factors affecting trust using the standardized format.

The Effect of 13 Weeks Long-Distance Bicycle Riding on Inflammatory Response Indicators Related to Joint Cartilage and Muscle Damage.

This study was to investigate the effects of 13 weeks of long-distance cycling on biomarkers of joint cartilage, muscle damage and inflammation. All subjects in this study were seven participants of the "One Korea New-Eurasia Peace Cycle Expedition", in which they rode cycles from Berlin, Germany to Seoul, Korea for thirteen weeks. The total course of the expedition was divided into three sub-courses: course 1 (from Berlin to Moscow), course 2 (from Moscow to Ulaanbaatar) and course 3 (from Ulaanbaatar to Seoul). All the selected participants rode 87.4 km/day (course 1), 70.4 km/day (course 2) and 57.6 km/day (course 3) on average, respectively. We collected their blood samples before the expedition in Seoul (S1), after course 1 in Moscow (M), after course 2 in Ulaanbaatar (U) and after the expedition in Seoul (S2), to analyze biomarkers of joint cartilage damage (Cartilage Oligomeric Matrix Protein; COMP), muscle damage (Creatine Phosphokinase; CPK, Lactate Dehydrogenase; LDH, Myoglobin), inflammation (Interleukin-6; IL-6, Interleukin-1ß; IL-1ß, Tumor Necrosis Factor-α; TNF-α, C-Reactive Protein; CRP) and stress hormone (Cortisol). According to this result, COMP (S1; 188.37 ± 46.68 ng/mL) showed a significant increase after the expedition course 1 (M; 246.69 ± 51.69 ng/mL, p = 0.012) and course 2 (U; 237.09 ± 62.57 ng/mL, p = 0.047), and recovered to the stable state after expedition course 3 (S2; 218.46 ± 34.78. p = 0.047). Biomarkers of muscle damage (CPK, LDH and Myoglobin) and inflammation (IL-6, IL-1ß, TNF-α and CRP) were not significantly changed in all courses, but CRP (S1; 1.07 ± 0.76 ng/mL) showed a tendency to decrease after the expedition course 1 (M; 0.3 ± 0.1 mg/mL, p = 0.044). Lastly, the Cortisol level significantly increased in all courses (per p < 0.05), but the Cortisol level after expedition course 3 (S2; 21.00 ± 3.65 mg/mL) was lower than that of after the expedition course 1 (M; 24.23 ± 2.47 mg/mL, p = 0.028). In summary, it seems that repetitive and continuous 50−90 km/day of cycling can increase joint cartilage damage risk and stress hormone temporarily. However, this result suggests that the appropriate intensity of cycling for thirteen weeks does not increase physical damage, and rather enhances the human body to adapt to exercise training.

Effects of horseback riding exercise therapy on background electroencephalograms of elderly people.

[Purpose] This study investigated the effect of horseback riding exercise on the background electroencephalograms of elderly people who performed horseback riding for 8 weeks. [Subjects] Twenty elderly people were divided into the horseback riding exercise and control group (n = 10 each). [Methods] The exercise was performed for 15 minutes, 3 times per week for 8 weeks. Electroencephalograms were analyzed. Post-exercise evaluation was performed after 8 weeks. [Results] After the horseback riding exercise, the relative slower alpha power index was active in the T3 and P4 domains but suppressed in the Fp1, Fp2, F3, F4, T4, and P3 domains. Moreover, the relative faster alpha power index was active in all domains of the horseback riding exercise group but was suppressed in all domains of the control group. There was a significant difference between groups in the F3 domain. [Conclusion] The alpha power index increased significantly after horseback riding exercise, suggesting the exercise improved background electroencephalogram.

Effects of exercise therapy on muscular strength in firefighters with back pain.

[Purpose] The purpose of this study was to determine how an exercise program focusing on muscular strength could aid firefighters with chronic lower back pain. [Subjects] The research subjects were randomly assigned to two groups, the experimental group (n=8) and the control (n=8). [Methods] The experimental group performed two types of exercise programs four times per week for 8 weeks under supervision. Tests were performed before and after the 8 weeks of exercise in accordance with the Korea Occupational Safety and Health Agency's program. [Results] At the end of the 8 weeks of the rehabilitation program, abdominal muscular strength were significantly increased in the experimental group, and this indicates that the exercise therapy was effective for improvement of muscular strength. [Conclusion] We found that exercise therapy is an effective intervention that can reduce the pain of patients with chronic lower back pain. The firefighters with chronic lower back pain who participated in this study exhibited enhanced lower back muscular strength and obtained some additional benefits. They need regular exercise.

Effect of exercise performance by elderly women on balance ability and muscle function.

[Purpose] The aim of this study was to investigate the effect of an exercise intervention on the balance ability and muscle function of elderly women. [Subjects] The subjects were randomly divided into a control group (n=10) and an exercise group (n=10). [Methods] The subjects participated in an elastic band exercise program lasting for 8 weeks, exercising for 40 minutes, four days a week with resting terms of 60 sec. Subjects used a band corresponding to 60% of the strength of the color band with which repetitive exercise was possible up to twelve times. The subjects performed elastic band exercises, with variations to the number of band exercises according to the improvement of their physical fitness levels. When fifteen repetitive elastic band exercises could be performed with no damage of the body, we changed the band for one which was one level up from the former one and subjects used the same band for the upper body and lower body. [Results] Leg muscular strength measured as sit-stand repetitions in 30 s significantly increased in the exercise group after the intervention compared to before the intervention. Leg muscular endurance measured as the number of knee ups in 2 minutes significantly increased in the exercise group after the intervention compared to before the intervention. Balance measured by one-leg standing time with the eyes open significantly improved in the exercise group after the intervention compared to before the intervention. [Conclusion] Balance ability and muscle function significantly improved in the exercise group and showing that the intervention is effective at improving balance, muscle strength, and muscle endurance of elderly women.

Effects of exercise therapy on blood lipids of obese women.

[Purpose] The aim of this study was to examine the effects of exercise therapy on blood lipids of obese women. [Subjects] The subjects were 24 clinically obese women. [Methods] The subjects were divided into an exercise group (n=12), and a control group (n=12). The exercise group performed exercise for 10 weeks with diet restriction. We investigated how this type of exercise influenced blood lipids. Blood was taken before and after the intervention. The collected blood was centrifuged at 3,000 rpm for 10 minutes; and plasma was preserved at -73 °C. For hemanalysis, a medical laboratory was asked to analyze total cholesterol and triglyceride. The exercise was performed 5 times per week, and an exercise was performed every two days, and exercise program was composed of warm up, main exercise and cool down. [Results] There were significant differences between the two groups in blood lipid levels after the intervention. The differences between the two groups in TC and TG were significant. [Conclusion] TC and TG significantly inproved in the experimental group showing that the exercise was effective at improveing blood lipid levels.