Relationships between nitric oxide biomarkers and physiological outcomes following dietary nitrate supplementation.

Dietary nitrate (NO3-) supplementation can increase nitric oxide (NO) bioavailability, reduce blood pressure (BP) and improve muscle contractile function in humans. Plasma nitrite concentration (plasma [NO2-]) is the most oft-used biomarker of NO bioavailability. However, it is unclear which of several NO biomarkers (NO3-, NO2-, S-nitrosothiols (RSNOs)) in plasma, whole blood (WB), red blood cells (RBC) and skeletal muscle correlate with the physiological effects of acute and chronic dietary NO3- supplementation. Using a randomized, double-blind, crossover design, 12 participants (9 males) consumed NO3--rich beetroot juice (BR) (∼12.8 mmol NO3-) and NO3--depleted placebo beetroot juice (PL) acutely and then chronically (for two weeks). Biological samples were collected, resting BP was assessed, and 10 maximal voluntary isometric contractions of the knee extensors were performed at 2.5-3.5 h following supplement ingestion on day 1 and day 14. Diastolic BP was significantly lower in BR (-2 ± 3 mmHg, P = 0.03) compared to PL following acute supplementation, while the absolute rate of torque development (RTD) was significantly greater in BR at 0-30 ms (39 ± 57 N m s-1, P = 0.03) and 0-50 ms (79 ± 99 N m s-1, P = 0.02) compared to PL following two weeks supplementation. Greater WB [RSNOs] rather than plasma [NO2-] was correlated with lower diastolic BP (r = -0.68, P = 0.02) in BR compared to PL following acute supplementation, while greater skeletal muscle [NO3-] was correlated with greater RTD at 0-30 ms (r = 0.64, P=0.03) in BR compared to PL following chronic supplementation. We conclude that [RSNOs] in blood, and [NO3-] in skeletal muscle, are relevant biomarkers of NO bioavailability which are related to the reduction of BP and the enhanced muscle contractile function following dietary NO3- ingestion in humans.

Symptom structure of complex posttraumatic stress disorder among Chinese young adults with childhood trauma: a network analysis.

BACKGROUND: The 11th revision of the World Health Organization's International Classification of Diseases (ICD-11) includes a new disorder, complex posttraumatic stress disorder (CPTSD), the diagnostic applicability of which has not been discussed sufficiently in Chinese culture. The network approach to psychopathology enables investigation of the structure of disorders at the symptom level, which allows for analysis of direct symptom interactions. The main objectives of the present study were to explore CPTSD symptom structure and identify key symptoms in CPTSD among young adults in China. METHODS: The present study collected a large, stratified sample of Beijing university students (1368), ranging from 18 to 25 years old, the majority of whom (65.4%) were female. CPTSD symptoms were assessed using the International Trauma Questionnaire (ITQ). A regularized partial correlation network and Bayesian network were applied to estimate the network structure and the upstream symptoms of CPTSD, respectively. RESULTS: The regularized partial correlation network showed that the high central symptoms were feelings of failure and hypervigilance, while the bridge symptom between posttraumatic stress disorder (PTSD) and disturbance in self-organization (DSO) domains was long-term upset. The Bayesian network showed that external avoidance and hypervigilance symptoms were upstream in CPTSD symptoms. CONCLUSIONS: Hypervigilance is a central symptom that can be predictive of other symptoms of CPTSD. While feeling of failure is also a highly central symptom, it may be influenced by other symptoms. In the diagnosis and intervention of CPTSD, more attention should be given to hypervigilance symptoms.

Pursuing Harmony and Fulfilling Responsibility: A Qualitative Study of the Orientation to Happiness (OTH) in Chinese Culture.

Happiness is the ultimate life goal for most people, and the pursuit of happiness serves as the fundamental motivation driving human behavior. Orientation to Happiness (OTH) represents the aspect that individuals seek when making decisions or engaging in activities, including values, priorities, motivations, ideals, and goals. Nevertheless, existing research has predominantly approached OTH from an individualistic perspective, emphasizing an individual's internal emotional state and personal goals, thereby neglecting the significant influence of a collectivist cultural background on the pursuit of happiness. To address this research gap, our study employs qualitative research methods, enabling us to delve deeply into the intricate interplay between cultural context, societal influences, and individual motivations that collectively shape OTH. Our research is dedicated to understanding the structure of OTH within the Chinese cultural context. Through semi-structured interviews with 26 Chinese adults and the utilization of an inductive style of thematic analysis, we have identified two core themes within the OTH of Chinese adults: Self-focused and Other-focused. Notably, the "Other-focused" theme emphasizes the pursuit of group harmony and the fulfillment of group responsibilities, highlighting the paramount role of "relationships" in the study of happiness within collectivist cultures. This insight forms a robust foundation for future research in this area.

A New Factor "Otherism" Added to the Hedonic and Eudaimonic Motives for Activities Scale (HEMA) in Chinese Culture.

Due to different understandings of happiness, people adopt different tendencies to act, which is called orientation to happiness (OTH). Our previous study found that OTH had two core themes, Self-focused and Other-focused in Chinese culture, which was different from OTH structures in Western culture. However, no corresponding measurement tool has been developed or revised. The Hedonic and Eudaimonic Motives for Activities Scale (HEMA) was the most commonly used measurement tool of OTH in recent years. The present study aimed to develop a Chinese version of the HEMA. A total of 1729 Chinese adults participated in this study. The exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to examine the underlying structure of the Chinese version of the HEMA. The results supported the 3-factor structure of the translation instrument, and the 15-item scale had good convergent and discriminant validity. The three dimensions were named Hedonism, Eudaimonism, and Otherism. Among them, Otherism is a new dimension, which means "the pursuit of the harmony of the group and achieving happiness by fulfilling their responsibilities in the group". The revised tool was named the Hedonic, Eudaimonic, and Otheristic Motives for Activities Scale-Chinese (HEOMA-C). The results showed that the HEOMA-C has good reliability and validity. Overall, the present study provided an effective tool to assess the OTH in Chinese culture.

Reduction in blood pressure following acute dietary nitrate ingestion is correlated with increased red blood cell S-nitrosothiol concentrations.

Dietary nitrate (NO3-) supplementation can enhance nitric oxide (NO) bioavailability and lower blood pressure (BP) in humans. The nitrite concentration ([NO2-]) in the plasma is the most commonly used biomarker of increased NO availability. However, it is unknown to what extent changes in other NO congeners, such as S-nitrosothiols (RSNOs), and in other blood components, such as red blood cells (RBC), also contribute to the BP lowering effects of dietary NO3-. We investigated the correlations between changes in NO biomarkers in different blood compartments and changes in BP variables following acute NO3- ingestion. Resting BP was measured and blood samples were collected at baseline, and at 1, 2, 3, 4 and 24 h following acute beetroot juice (∼12.8 mmol NO3-, ∼11 mg NO3-/kg) ingestion in 20 healthy volunteers. Spearman rank correlation coefficients were determined between the peak individual increases in NO biomarkers (NO3-, NO2-, RSNOs) in plasma, RBC and whole blood, and corresponding decreases in resting BP variables. No significant correlation was observed between increased plasma [NO2-] and reduced BP, but increased RBC [NO2-] was correlated with decreased systolic BP (rs = -0.50, P = 0.03). Notably, increased RBC [RSNOs] was significantly correlated with decreases in systolic (rs = -0.68, P = 0.001), diastolic (rs = -0.59, P = 0.008) and mean arterial pressure (rs = -0.64, P = 0.003). Fisher's z transformation indicated no difference in the strength of the correlations between increases in RBC [NO2-] or [RSNOs] and decreased systolic blood pressure. In conclusion, increased RBC [RSNOs] may be an important mediator of the reduction in resting BP observed following dietary NO3- supplementation.

A Plyometric Warm-Up Protocol Improves Running Economy in Recreational Endurance Athletes.

This study explored the impact of two differing warm-up protocols (involving either resistance exercises or plyometric exercises) on running economy (RE) in healthy recreationally active participants. Twelve healthy university students [three males, nine females, age 20 ± 2 years, maximal oxygen uptake (38.4 ± 6.4 ml min-1 kg-1)] who performed less than 5 h per week of endurance exercise volunteered to participant in this study. All participants completed three different warm-up protocols (control, plyometric, and resistance warm-up) in a counterbalanced crossover design with trials separated by 48 h, using a Latin-square arrangement. Dependent variables measured in this study were RE at four running velocities (7, 8, 9, and 10 km h-1), maximal oxygen uptake; heart rate; respiratory exchange rate; expired ventilation; perceived race readiness; rating of perceived exertion, time to exhaustion and leg stiffness. The primary finding of this study was that the plyometric warm-up improved RE compared to the control warm-up (6.2% at 7 km h-1, ES = 0.355, 9.1% at 8 km h-1, ES = 0.513, 4.5% at 9 km h-1, ES = 0.346, and 4.4% at 10 km h-1, ES = 0.463). There was no statistically significant difference in VO2 between control and resistance warm-up conditions at any velocity. There were also no statistically significant differences between conditions in other metabolic and pulmonary gas exchange variables; time to exhaustion; perceived race readiness and maximal oxygen uptake. However, leg stiffness increased by 20% (P = 0.039, ES = 0.90) following the plyometric warm-up and was correlated with the improved RE at a velocity of 8 km h-1 (r = 0.475, P = 0.041). No significant differences in RE were found between the control and resistance warm-up protocols. In comparison with the control warm-up protocol, an acute plyometric warm-up protocol can improve RE in healthy adults.