High-Performance Multi-Level Inverter with Symmetry and Simplification.

This paper presents a high-performance, multilevel inverter with symmetry and simplification. This inverter is a single-phase, seven-level symmetric switched-capacitor inverter based on the concept of the double voltage clamping circuit connected to the half-bridge circuit. Above all, only a single DC power supply is used to achieve a single-phase inverter with seven levels and a voltage gain of three. In addition to analyzing the operating principle of the proposed switched-capacitor multilevel inverter in detail, the stability analysis and controller design are carried out by the state-space averaging method. The feasibility and effectiveness of the proposed structure are validated by some simulated results based on the PSIM simulation tool and by some experiments using FPGA as a control kernel, respectively. However, in this study, the switches were implemented by MOSFETs to meet a high switching frequency. These MOSFETs can be replaced by IGBTs in the motor drive applications so that the used switching frequency can be reduced.

Effects of concurrent aerobic and resistance training on vascular health in type 2 diabetes: a systematic review and meta-analysis.

Objective: To determine the impacts of concurrent aerobic and resistance training on vascular structure (IMT) and function (PWV, FMD, NMD) in type 2 diabetes (T2D). Methods: The electronic databases PubMed, Web of Science Core Collection, Cochrane Library, Embase, Scopus, CINAHL, and SPORTDiscus were systematically searched for articles on "type 2 diabetes" and "concurrent training" published from inception to August 2, 2022. We included randomized controlled trials that examined the effects of concurrent training versus passive controls on IMT, PWV, FMD and NMD in T2D. Results: Ten studies were eligible, including a total of 361 participants. For IMT, concurrent training showed a slight decrease by 0.05 mm (95% CI -0.11 to 0.01, p > 0.05). concurrent training induced an overall significant improvement in FMD by 1.47% (95% CI 0.15 to 2.79, p < 0.05) and PWV by 0.66 m/s (95% CI -0.89 to -0.43, p < 0.01) in type 2 diabetics. However, concurrent training seemed to exaggerate the impaired NMD (WMD = -2.30%, 95% CI -4.02 to -0.58, p < 0.05). Conclusions: Concurrent training is an effective method to improve endothelial function and artery stiffness in T2D. However, within 24 weeks concurrent training exacerbates vascular smooth muscle dysfunction. More research is needed to explore whether longer and/or higher-intensity concurrent training interventions could enhance the vascular structure and smooth muscle function in this population. Systematic review registration: www.crd.york.ac.uk/PROSPERO/, identifier CRD42022350604.

The impact of physical activity on electronic media use among chinese adolescents and urban-rural differences.

OBJECTIVE: With the prevalence of electronic media use among Chinese adolescents and concerns regarding its potential negative consequences on their health and development, this study investigated the relationship between physical exercise and electronic media use. Utilizing data from the China Education Panel Survey, we examine the impact of physical activity on adolescents' electronic media use. METHODS: A simultaneous equation model, including two-stage least square and three-stage least square, was employed to estimate the impact of physical activity on electronic media use among adolescents. Self-control theory and media addiction theory were also used to analyze electronic media use in adolescents. Descriptive statistics were used to analyzed the data. RESULTS: Chinese adolescents dedicated a substantial amount of time, averaging 2.95 hours per day, to electronic media activities. Increasing physical activity demonstrated an effective means to reduce electronic media use. Furthermore, the impact of physical activity on electronic media use exhibited urban-rural stratification, with family factors related to social class status primarily influencing electronic media use among urban students, while physical activity has a more pronounced influence among rural students. CONCLUSIONS: Promoting physical activity represents a compelling and effective strategy for curbing excessive electronic media use among Chinese adolescents, particularly in rural areas where physical activity has a stronger influence. In addition, controlling media entertainment and recreation time and enhancing social cohesion can help to weaken media interest. While changing the social class status of families in urban areas may be difficult in the short term, parents should be aware that physical exercise is an effective way to reduce their children's use of electronic media. Our findings suggested that promoting physical activity may be a promising strategy for reducing excessive electronic media use among Chinese adolescents, particularly in rural areas where physical activity has a stronger influence.

Downhill running induced DNA damage enhances mitochondrial membrane permeability by facilitating ER-mitochondria signaling.

To observe whether downhill running can lead to DNA damage in skeletal muscle cells and changes in mitochondrial membrane permeability and to explore whether the DNA damage caused by downhill running can lead to changes in mitochondrial membrane permeability by regulating the components of the endoplasmic reticulum mitochondrial coupling structure (MAM). A total of 48 male adult Sprague-Dawley rats were randomly divided into a control group (C, n = 8) and a motor group (E, n = 40). Rats in Group E were further divided into 0 h (E0), 12 h (E12), 24 h (E24), 48 h (E48) and 72 h (E72) after prescribed exercise, with 8 rats in each group. At each time point, flounder muscle was collected under general anaesthesia. The DNA oxidative damage marker 8-hydroxydeoxyguanosine (8-OHdG) was detected by immunofluorescence. The expression levels of the DNA damage-related protein p53 in the nucleus and the EI24 protein and reep1 protein in whole cells were detected by Western blot. The colocalization coefficients of the endoplasmic reticulum protein EI24 and the mitochondrial protein Vdac2 were determined by immunofluorescence double staining, and the concentration of Ca2+ in skeletal muscle mitochondria was detected by a fluorescent probe. Finally, the opening of the mitochondrial membrane permeability transition pore (mPTP) was detected by immunofluorescence. Twelve hours after downhill running, the mitochondrial membrane permeability of the mPTP opened the most (P < 0.05), the content of 8-OHdG in skeletal muscle peaked (P < 0.05), and the levels of the regulatory protein p53, mitochondrial Ca2+, and the EI24 and reep1 proteins peaked (P < 0.01). Moreover, the colocalization coefficients of EI24 and Vdac2 and the Mandes coefficients of the two proteins increased first and then recovered 72 h after exercise (P < 0.05). (1) Downhill running can lead to DNA damage in skeletal muscle cells, overload of mitochondrial Ca2+ and large opening of membrane permeability transformation pores. (2) The DNA damage caused by downhill running may result in p53 promoting the transcriptional activation of reep1 and EI24, enhancing the interaction between EI24 and Vdac2, and then leading to an increase in Ca2+ in skeletal muscle mitochondria and the opening of membrane permeability transition pores.

Serum miRNAs miR-23a, 206, and 499 as Potential Biomarkers for Skeletal Muscle Atrophy.

Muscle biopsy has long been expected to be replaced by noninvasive biomarkers with diagnostic value and prognostic applications for muscle atrophy. Growing evidence suggests that circulating microRNAs (miRNAs) could act as biomarkers for numerous pathophysiological statuses. In the present study, our results showed that the serum levels of six muscle-specific miRNAs (miR-1/23a/133/206/208b/499) were all elevated in unloading induced mice. The medium levels of these six muscle-specific miRNAs were all elevated in starvation induced atrophic C2C12 myotubes. Moreover, the serum levels of miR-23a/206/499 were induced in participants after 45 days of head-down bed rest (HDBR). The levels of miR-23a/206/499 were positively correlated with the ratio of soleus volume loss in HDBR participants, indicating that they might represent the process of muscle loss. In conclusion, our results demonstrated that circulating miRNAs could serve as useful biochemical and molecular indicators for muscle atrophy diagnosis and disease progression.

[Regulative Role For Noncoding RNAs During Skeletal Muscle Development and Disease].

Noncoding RNAs, including long noncoding RNAs (IncRNAs) and microRNAs (miRNAs), are close to myogenesis, regulating of muscle fiber type and muscle diseases. Recently, circulating ncRNAs have become research focus for they could as potential biomarkers for the screening and early diagnosis of some diseases. We are confident that the role of nccoding RNAs during skeletal muscle development will bring potential target for treatment of muscle diseases in the future.

Effect of biocontrol agent Pseudomonas fluorescens 2P24 on soil fungal community in cucumber rhizosphere using T-RFLP and DGGE.

Fungi and fungal community play important roles in the soil ecosystem, and the diversity of fungal community could act as natural antagonists of various plant pathogens. Biological control is a promising method to protect plants as chemical pesticides may cause environment pollution. Pseudomonas fluorescens 2P24 had strong inhibitory on Rastonia solanacearum, Fusarium oxysporum and Rhizoctonia solani, etc., and was isolated from the wheat rhizosphere take-all decline soils in Shandong province, China. However, its potential effect on soil fungal community was still unknown. In this study, the gfp-labeled P. fluorescens 2P24 was inoculated into cucumber rhizosphere, and the survival of 2P24 was monitored weekly. The amount decreased from 10(8) to 10(5) CFU/g dry soils. The effect of 2P24 on soil fungal community in cucumber rhizosphere was investigated using T-RFLP and DGGE. In T-RFLP analysis, principle component analysis showed that the soil fungal community was greatly influenced at first, digested with restriction enzyme Hinf I and Taq I. However, there was little difference as digested by different enzymes. DGGE results demonstrated that the soil fungal community was greatly shocked at the beginning, but it recovered slowly with the decline of P. fluorescens 2P24. Four weeks later, there was little difference between the treatment and control. Generally speaking, the effect of P. fluorescens 2P24 on soil fungal community in cucumber rhizosphere was just transient.

High myopia as a risk factor in primary open angle glaucoma.

Glaucoma, one of the leading causes of irreversible blindness in the adult population worldwide, is a progressive optic neuropathy. Primary open angle glaucoma (POAG) is the most commonly reported type of glaucoma in population based prevalence studies worldwide. Elevated intraocular pressure is a well-known major risk factor for POAG. In addition, there is growing evidence that other risk factors like age, gender, race, refractive error, heredity and systemic factors may play a role in glaucoma pathogenesis. Many studies found that high myopia has been associated with POAG, however, direct and convincing evidences are still lacking. The aim of this review is to summarize the evidences implicating high myopia as a risk factor in the pathogenesis of POAG.

Prevalence of ocular disease in Tibetan primary school children.

BACKGROUND: There is very little information on the prevalence of ocular diseases in Tibetan children who live in the remote areas of the Qinghai-Tibetan Plateau. The purpose of this study was to investigate the prevalence of ocular diseases in primary school children between 6 and 14 years of age in the rural Tibetan area of Maqin County, China. METHODS: All the children from 8 Tibetan township primary schools in Maqin County underwent a full eye examination by a team of 6 senior ophthalmologists. RESULTS: A total of 1084 children were included in this investigation, of which 199 (18.36%, 95% confidence interval [CI] 16.05-20.66) had ocular morbidity. Of these, 98 were male and 101 were female. Refractive errors were found in 11.07% (95% CI 9.20-12.94), strabismus in 2.49% (95% CI 1.56-3.42), corneal leukoma in 1.20% (95% CI 0.55-1.85), amblyopia in 1.02% (95% CI 0.42-1.61), and vernal conjunctivitis in 0.65% (95% CI 0.17-1.12). Monocular blindness was seen in 16 cases (1.48%, 95% CI 0.76-2.19). Trauma was the most common cause of blindness. INTERPRETATION: The prevalence of eye disorder is high among school-aged Tibetan children in Maqin County, representing an important health problem. More effort should be devoted to the study, prevention, and treatment of these diseases. Effective strategies are needed to reduce the incidence of visual impairment in this population of children.