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Background: Tai Chi, originating in China, is a mind–body exercise that integrates mind training, Qi training, and body training. While Tai Chi practice has demonstrated beneficial physical and psychological health benefits, how it achieves effects has been less studied. In recent years, some researchers have begun to explore the potential of heart rate variability (HRV) changes as balancing the autonomic nervous system (ANS) to achieve results, but only a few studies have directly tested how Tai Chi impacts HRV, and results have been mixed. Objective: This study systematically evaluates the effects of Tai Chi on HRV. Methods: Electronic databases including Web of Science, PubMed, Scopus, Cochrane Library, and EBSCOhost direct from inception until December 2020 were searched to obtain eligible studies. The primary outcomes examined were HRV parameters (time domain and frequency domain), and secondary analysis was whether breathing was emphasized during Tai Chi interventions. Results: Based on the 11 randomized controlled trials included comparing Tai Chi with non-active control condition, meta-analyses showed significantly beneficial effects on HRV parameters (low-frequency power [LF], mean difference [MD] = −200.40, 95% confidence interval [CI]: 365.31 to −35.49, p = 0.02; normalized low-frequency power [nLF], MD = −7.39, 95% CI: −12.48 to −2.29, p = 0.004; total power [TP], MD = −649.82, 95% CI: −1180.54 to −119.11, p = 0.02; very low-frequency power [VLF], MD = −200.55, 95% CI: −349.63 to −51.46, p = 0.008; root mean square of the square sum of the difference between adjacent normal heartbeat intervals [RMSSD], MD = 2.59, 95% CI: −7.23 to 12.41, p < 0.0001; standard deviation of the heartbeat interval [SDNN], MD = 8.33, 95% CI: 0.69 to 15.98, p = 0.03). The effect of Tai Chi on certain HRV parameters compared with active control conditions was less favorable (nLF, MD = 6.42, 95% CI: 3.74 to 9.09, p < 0.00001; normalized high-frequency power [nHF], MD: −6.13, 95% CI: −8.76 to −3.50, p < 0.00001; low-frequency/high-frequency power ratio [LF/HF], MD = 1.00, 95% CI: 0.68 to 1.33, p < 0.00001). In addition, studies describing an emphasis on breathing in the Tai Chi intervention showed positive impact on HRV (nLF, MD = −3.22, 95% CI: −5.32 to −1.12, p = 0.003; nHF, MD = 3.80, 95% CI: 0.80 to 6.81, p = 0.01; SDNN, MD = 5.55, 95% CI: 4.85 to 6.25, p < 0.00001). Conclusions: Meta-analysis results showed that Tai Chi compared with non-active control conditions has a positive impact on key HRV parameters associated with the ANS balance. However, active control condition comparisons showed greater HRV improvements than for Tai Chi. Considering the limited number of studies and their heterogeneity, further robust studies are necessary to verify findings and investigate differential effects of Tai Chi on HRV. [ABSTRACT FROM AUTHOR]

Introduction: Limited studies have explored the clinical features, treatment, and prognosis of neonatal tuberculosis (TB). Here, we attempted to delineate the clinical characteristics of neonatal TB, which may help clinicians further understand this disease. Methods: A retrospective analysis of neonates diagnosed with congenital and/or neonatal TB disease from January 2010 to December 2020 was performed. Information on the demographic and epidemiological features, clinical symptoms, laboratory and imaging examinations, therapeutic regimens, and outcomes was collected. Kaplan-Meier analysis was used to present the time to disease onset, time to diagnosis, etc. Results: Forty-eight cases of neonatal TB were classified into congenital (n = 33) and postnatal (n = 15). The median time to disease onset in postnatal group was significantly longer than that in congenital group. Positive results for gastric fluid acid-fast bacilli, TB culture, Xpert MTB/RIF, interferon-γ release assay (IGRA), and tuberculin skin test were detected in 26/48 (54.2%), 14/34 (41.2%), 11/18 (61.1%), 19/29 (65.5%), and 8/24 (33.3%) patients, respectively. For lymphadenopathy, computed tomography (CT) scans showed a higher detection rate than did X-ray (80.0% vs. 0). Of the 48 infants, 44/48 (91.7%) received anti-TB therapy, and 33/44 (75%) were clinically improved or cured after 22.1 months (interquartile range: 12.4–27.7) of follow-up. Drug-induced liver injury occurred in 14/44 (31.8%) patients. Discussion/Conclusion: IGRA and Xpert MTB/RIF showed good positive rate in neonatal TB infection/disease. In cases where TB is presumed but etiological evidence is lacking, low-dose CT could be considered. Prompt treatment under careful surveillance is important for preventing mortality and avoiding severe adverse effects. [ABSTRACT FROM AUTHOR]

Non-contact temperature measurement at the nanoscale by photoluminescence using a nano-sensor in a confined fluid has been performed in the present work. Upconversion lanthanide-doped nanoparticles applied to ratiometric thermometry could be considered as a self-referenced nanosensor. Gadolinium orthovanadate (GdVO4) nanoparticles doped with Yb3+ and Er3+ were synthesized and then dispersed in an ester-based fluid. Rheological measurements show that the viscosity of the dispersed NP suspension remains unchanged up to a shear rate of 10−4 s−1 at 393 K. The NP suspension allows luminescence intensity ratio (LIR) thermometry up to 473 K with a relative sensitivity of 1.17% K−1 with a NIR laser. Then, the temperature calibration by coupling the high pressure (1.08 GPa max) confirmed the applicability of NPs as a thermosensor in a variable pressure environment. According to these results, the fluid containing GdVO4:Yb3+/Er3+ nanoparticles can be used for temperature sensing in a pressurized environment for further application in tribology. [ABSTRACT FROM AUTHOR]

This study tested the hypothesis that brassinosteroids (BRs) mediate moderate soil‐drying (MD) to alleviate spikelet degeneration under high temperature (HT) stress during meiosis of rice (Oryza sativa L.). A rice cultivar was pot‐grown and subjected to normal temperature (NT) and HT treatments during meiosis, and two irrigation regimes including well‐watered (WW) and MD were imposed to the plants simultaneously. The MD effectively alleviated the spikelet degeneration and yield loss under HT stress mainly via improving root activity and canopy and panicle traits including higher photosynthetic capacity, tricarboxylic acid cycle activity, and antioxidant capacity than WW. These parameters were regulated by BRs levels in plants. The decrease in BRs levels at HT was due mainly to the enhanced BRs decomposition, and the MD could rescue the BRs deficiency at HT via enhancing BRs biosynthesis and impeding decomposition. The connection between BRs and HT was verified by using rice BRs‐deficient mutants, transgenic rice lines, and chemical regulators. Similar results were obtained in the open‐air field experiment. The results suggest that BRs can mediate the MD to alleviate spikelet degeneration under HT stress during meiosis mainly via enhancing root activity, canopy traits, and young panicle traits of rice. Summary statement: Brassinosteroids can mediate the moderate soil‐drying to alleviate spikelet degeneration under high temperature stress during meiosis mainly via enhancing root activity, canopy photosynthetic capacity, and tricarboxylic acid cycle activity and antioxidant capacity in young panicles of rice (Oryza sativa L.). [ABSTRACT FROM AUTHOR]

Photoluminescent temperature sensors based on gadolinium orthovanadate (GdVO4) doped with 10% ytterbium and 2% erbium are developed and dispersed in different media (lubricant fluid, sol–gel glass, and PDMS) to evaluate the best conditions for temperature measurement. Two excitation modes are considered: (i) visible excitation by a downshifting (DS) process or (ii) NIR excitation by energy transfer upconversion (UC) between Yb and Er. The luminescence intensity ratio (LIR) of the thermally coupled Er3+ emission peaks varies linearly with temperature in the range of 25–300 °C, and this variation is reversible. The impact of the laser power density on thermometry via the UC process that has been verified with GdVO4: Yb3+/Er3+ powders and with its different dilutions (low and high concentration) shows that the LIR is highly dependent on the laser source intensity, the environmental temperature, and the dispersed medium. When GdVO4: Yb3+/Er3+ powders are dispersed at high concentration, high laser power density leads to significant laser-induced thermal heating. However, at low concentration, this laser thermal effect is no longer influenced by the laser intensity. In this paper, we propose a method to directly measure the laser-induced heating temperature and to correct the error caused by this effect on temperature measurement. According to these results, GdVO4: Yb3+/Er3+ upconversion nanoparticles can be applied for temperature sensing even if the laser-induced thermal effect occurs in the system. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of 8-week aquatic and land high intensity interval training (HIIT) on hemodynamics and vascular function in middle-aged men. Methods: Thirty middle-aged men with low physical activity were selected and divided into 15 men (52.43 ± 4.11) in aquatic group and 15 men (52.74 ± 5.62) in land group by random number table. They performed HIIT exercise in aquatic and land 3 times a week for 8 weeks. Pre-test, inter-test and post-test respectively measure hemodynamics and blood vessel function. Results: (1) Body composition: After 8 weeks of exercise, weight, body mass index (BMI) and body fat rate (BF) were lower than before exercise (aquatic group: p < 0.01, land group: p < 0.05). The improvement of BF in the aquatic group was better than that in the land group ( p < 0.05); (2) Cardiac function: After 8 weeks of exercise, stroke volume (SV), left ventricular end-diastolic volume (EDV), cardiac output (CO), and left ventricular fractional shortening (FS), were higher than before exercise (aquatic group: p < 0.01, land group: p < 0.05), heart rate (HR) and left ventricular end-systolic volume (ESV) were lower than before exercise (aquatic group: p < 0.01, land group: p < 0.05). The improvement of SV, HR, EDV, ESV, CO and FS in the aquatic group was better than that in the land group ( p < 0.05); (3) Hemodynamics: After 8 weeks of exercise, systolic blood pressure (SBP), diastolic blood pressure (DBP) were lower than before exercise (aquatic group: p < 0.01, land group: p < 0.05), wall shear stress (WSS) and peak systolic velocity (PSV) were higher than before exercise (aquatic group: p < 0.01, land group: p < 0.05). The improvement of SBP, WSS and PSV in the aquatic group was better than that in the land group ( p < 0.05); (4) Vascular function: basal diameter and brachial artery flow-mediated dilatation (FMD) level in aquatic group and land group was higher than before exercise, pulse wave velocity (PWV) level was lower than before exercise (aquatic and land group: p < 0.05). The improvement of FMD in the aquatic group was better than that in the land group. Conclusion: The body composition, hemodynamics and vascular function of middle-aged men were improved by 8-week aquatic and land HIIT. Aquatic HIIT has better effect on body fat rate, hemodynamics and vascular endothelial function in middle-aged men due to the effect of aquatic pressure and temperature., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Xin, Fu, Zhou, Zhou and He.)

Non-contact temperature measurement at the nanoscale by photoluminescence using a nano-sensor in a confined fluid has been performed in the present work. Upconversion lanthanide-doped nanoparticles applied to ratiometric thermometry could be considered as a self-referenced nanosensor. Gadolinium orthovanadate (GdVO 4 ) nanoparticles doped with Yb 3+ and Er 3+ were synthesized and then dispersed in an ester-based fluid. Rheological measurements show that the viscosity of the dispersed NP suspension remains unchanged up to a shear rate of 10 -4 s -1 at 393 K. The NP suspension allows luminescence intensity ratio (LIR) thermometry up to 473 K with a relative sensitivity of 1.17% K -1 with a NIR laser. Then, the temperature calibration by coupling the high pressure (1.08 GPa max) confirmed the applicability of NPs as a thermosensor in a variable pressure environment. According to these results, the fluid containing GdVO 4 :Yb 3+ /Er 3+ nanoparticles can be used for temperature sensing in a pressurized environment for further application in tribology.