Nanostructure engineering of Pt/Pd-based oxygen reduction reaction electrocatalysts.

Increasing the atomic utilization of Pt and Pd elements is the key to the advancement and broad dissemination of fuel cells. Central to this task is the design and fabrication of highly active and stable Pt- or Pd-based electrocatalysts for the oxygen reduction reaction (ORR), which requires a comprehensive understanding of the ORR pathways and mechanism. Past endeavors have accumulated a wealth of knowledge about the Pt/Pd-based ORR electrocatalysts based on structure engineering, while a systematic review of the nanostructure engineering of Pt/Pd-based ORR electrocatalysts has been rarely reported. In this review, we provide a systematic discussion about the current status of Pt/Pd-based ORR electrocatalysts from the perspective of nanostructure engineering, and we highlight the ORR pathways, mechanisms and theories in order to understand the ORR in a more complex nanocatalyst. Particularly, the underlying structure-function relationship of Pt/Pd-based ORR electrocatalysts is specifically highlighted, which will guide the future synthesis of more efficient ORR electrocatalysts.

A balance between vector survival and virus transmission is achieved through JAK/STAT signaling inhibition by a plant virus.

Viruses pose a great threat to animal and plant health worldwide, with many being dependent on insect vectors for transmission between hosts. While the virus-host arms race has been well established, how viruses and insect vectors adapt to each other remains poorly understood. Begomoviruses comprise the largest genus of plant-infecting DNA viruses and are exclusively transmitted by the whitefly Bemisia tabaci. Here, we show that the vector Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway plays an important role in mediating the adaptation between the begomovirus tomato yellow leaf curl virus (TYLCV) and whiteflies. We found that the JAK/STAT pathway in B. tabaci functions as an antiviral mechanism against TYLCV infection in whiteflies as evidenced by the increase in viral DNA and coat protein (CP) levels after inhibiting JAK/STAT signaling. Two STAT-activated effector genes, BtCD109-2 and BtCD109-3, mediate this anti-TYLCV activity. To counteract this vector immunity, TYLCV has evolved strategies that impair the whitefly JAK/STAT pathway. Infection of TYLCV is associated with a reduction of JAK/STAT pathway activity in whiteflies. Moreover, TYLCV CP binds to STAT and blocks its nuclear translocation, thus, abrogating the STAT-dependent transactivation of target genes. We further show that inhibition of the whitefly JAK/STAT pathway facilitates TYLCV transmission but reduces whitefly survival and fecundity, indicating that this JAK/STAT-dependent TYLCV-whitefly interaction plays an important role in keeping a balance between whitefly fitness and TYLCV transmission. This study reveals a mechanism of plant virus-insect vector coadaptation in relation to vector survival and virus transmission.

The Effects of Active Video Game Exercise Based on Self-Determination Theory on Physical Fitness and Cognitive Function in Older Adults.

BACKGROUND: Aging and physical inactivity are associated with declines in physical fitness and cognitive function. Active video games have proven to be beneficial for the physical health of older adults, but the exact effect of active video games on physical fitness and cognitive function was still unclear. Based on self-determination theory (SDT), which is a widely used theory of healthy behavior change, this study aimed to explore the effects of an active video game intervention on fitness and cognitive function in older adults. METHODS: A total of 38 participants (mean age = 65.68 ± 3.78 years, 24 female) were randomly assigned to either an intervention group (active video game training) or a control group (no additional intervention). The participants in the intervention group trained for a total of 36 sessions (3 times per week for 50-55 min each) for 12 weeks. The control group continued with their normal daily living. The pre- and posttest measurements included: IPAQ-C score and physical fitness (BMI, body fat percent, blood pressure, reaction time, sit and reach, vital capacity, grip strength, static balance, blood biochemical tests for liver function, kidney function, blood lipids, glucose and insulin levels) and cognitive functions (processing speed, spatial ability, working memory, language ability, associative memory). RESULT: The intervention group showed a significantly smaller decrease in total average physical activity relative to the control group. BMI, vital capacity, systolic blood pressure, diastolic blood pressure, and spatial cognition significantly improved after training in the intervention group (BMI: F = 9.814, p = 0.004, d = -0.93, vital capacity: F = 4.708, p = 0.038, d = 0.67, systolic blood pressure: F = 5.28, p = 0.028, d = -0.68, diastolic blood pressure: F = 6.418, p = 0.016, d = -0.86, spatial cognition: F = 8.261, p = 0.007, d = 0.72). Three measures of static balance (closed eyes) also showed improvements after training (total length of swing: F = 3.728, d = -0.62, total velocity of swing: F = 3.740, d = -0.62, total area of swing: F = 2.920, d = -0.70). No significant training effects were evident in the results from the blood biochemical tests. CONCLUSION: This study indicates a positive influence of active video game training on physical fitness and cognitive function. The use of SDT-based active video game exercise as a feasible, safe, and effective training method for improving community older adults' healthy, promoting group cohesion, and increasing motivation to exercise.

Whitefly HES1 binds to the intergenic region of Tomato yellow leaf curl China virus and promotes viral gene transcription.

Intergenic region of begomovirus genome is vital to virus replication and viral gene transcription in plants. Previous studies have reported that Tomato yellow leaf curl China virus (TYLCCNV), a begomovirus, is able to accumulate and transcribe in its whitefly vector. However, the viral and host components that participate in begomovirus transcription in whiteflies are hitherto unknown. Using a yeast one-hybrid system, we identified >50 whitefly proteins that interacted with TYLCCNV intergenic region. Dual luciferase analysis revealed that one of the identified proteins, the hairy and enhancer of split homolog-1 (HES1), specifically bound to CACGTG motif in TYLCCNV intergenic region. Silencing HES1 decreased viral transcription, accumulation and transmission. These results demonstrate that the interactions between whitefly proteins and the intergenic region of TYLCCNV may contribute to viral transcription in the whitefly vector. Our findings offer valuable clues for the research and development of novel strategies to interfere with begomovirus transmission.