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In order to study the influence of load change on the meshing characteristics of cycloid pinwheel of RV reducer, considering the modification of cycloid tooth profile, the three-dimensional model of cycloid pinwheel mechanism was established by UG. The changes of meshing tooth pairs and meshing stress of cycloid pinwheel in a meshing transmission cycle were analyzed by using the transient dynamics module of Ansys, and the simulation was compared with the theoretical contact stress. Results show that the overall trend of contact stress between simulation and theory is consistent, the number of meshing teeth and meshing stress of cycloid pinwheel show a periodic law, and increase with the increase of load. The change trend of contact stress and equivalent stress is opposite to the number of meshing teeth, the more the number of meshing teeth, the smaller the meshing stress. The equivalent stress of the needle tooth in the length direction increases with the increase of load, and the stress has a trend of uniform distribution, but the change is small. The finite element analysis has certain reference significance for the design, analysis and manufacture of RV reducer.

Purpose: The objective of this study is to assess the carrier frequency and pathogenic variation of monogenetic diseases in a population of 114 subjects in Han Chinese from Hebei province who are undergoing assisted reproductive technology through the utilization of Expanded Carrier Screening (ECS). Methods: The study utilized a panel consisting of 155 severe monogenic recessive genetic diseases for ECS. Next-generation sequencing technology was employed to identify specific variants associated with ECS in a cohort of 114 subjects from 97 couples, comprising 97 females and 17 male spouses. Results: A total of 114 individuals received ECS. The carrier rate of pathogenic genes in the enrolled population was 44.74% (51/114). Among the 97 females, the carrier rate of pathogenic genes was higher in those without assisted reproduction indicators than in those with assisted reproduction indicators (59.09% vs. 41.33%). However, the carrier rate of pathogenic genes in males without assisted reproductive technology was slightly lower than that with assisted reproductive technology (40% vs. 41.67%). Among both female and male participants, the carrier rate of pathogenic genes between individuals without indicators of assisted reproduction and those with such indicators was 55.55% vs. 41.38%. In 51 carriers, 72.55% (37/51) carried one genetic variant, 25.49% (13/51) carried two genetic variants, and 1.96% (1/51) carried three genetic variants. A total of 38 pathogenic genes were detected in this study, and GJB2 and MMACHC were most common. The carrier rates of the two genes were both 5.26% (6/114). A total of 55 variations were detected, and c.235delC was most frequently found. The carrier rate was 3.51% (4/114). The incidence of couples carrying the same pathogenic genes was 1.03% (1/97). Conclusions: The findings elucidate the carrier rate of pathogenic genes among 155 severe monogenic recessive genetic diseases and underscore the significance of ECS as a preventive measure against congenital anomalies. When both partners carry the same genetic mutation for a monogenic disease, preventive strategies can be taken in offspring through preimplantation genetic testing (PGT), prenatal genetic testing, or the utilization of donor gametes. ECS is instrumental in assessing reproductive risk, guiding fertility-related decisions, and reducing the prevalence of monogenic recessive genetic disorders in subsequent generations. [ABSTRACT FROM AUTHOR]

DNA damage is a key factor affecting gametogenesis and embryo development. The integrity and stability of DNA are fundamental to a woman's successful conception, embryonic development, pregnancy and the production of healthy offspring. Aging, reactive oxygen species, radiation therapy, and chemotherapy often induce oocyte DNA damage, diminished ovarian reserve, and infertility in women. With the increase of infertility population, there is an increasing need to study the relationship between infertility related diseases and DNA damage and repair. Researchers have tried various methods to reduce DNA damage in oocytes and enhance their DNA repair capabilities in an attempt to protect oocytes. In this review, we summarize recent advances in the DNA damage response mechanisms in infertility diseases such as PCOS, endometriosis, diminished ovarian reserve and hydrosalpinx, which has important implications for fertility preservation. [ABSTRACT FROM AUTHOR]

To improve the adaptability of the robot pan–tilt to the high-temperature environment, a design scheme for a composite thermal protection structure composed of aerogel felt, hollow glass, and skin is proposed. The effects of aerogel felt thickness, glass type, and ambient temperature on the thermal protection performance of the structure are studied, using a fluid–solid–thermal coupling model. Numerical results show that the structure exhibits good protection performance, and that the thermal resistance distribution changes the main path of heat transmission. The optimal thickness of the aerogel felt is approximately 8 mm. Compared to 3 mm, 5 mm, and 10 mm thicknesses, 8 mm reduces the maximum temperature by 15.90%, 8.37%, and 6.22%, and reduces the total entropy by 79.23%, 52.44%, and 12.5%. Lower thermal conductivity of the gas inside the hollow glass results in decreased maximum temperatures and total entropy. Using argon-filled hollow glass at 573.15 K decreases maximum temperature by 33.52% and 8.40%, with a total entropy reduction of 33.46% and 6.04%, compared to the single-layer and air-filled glass. Higher ambient temperatures correlate with increased maximum temperature, total entropy, and average surface-heat-transfer coefficient, indicating that the adaptability of the structure to high-temperature environments is limited. [ABSTRACT FROM AUTHOR]

A facile one-pot two-enzyme chemoenzymatic approach has been established for the gram (Neu4,5Ac2α3Lac, 1.33 g) and preparative scale (Neu4,5Ac2α3LNnT) synthesis of monotreme milk oligosaccharides. Other O-acetyl-5-N-acetylneuraminic acid (Neu4,5Ac2)- or 4-O-acetyl-5-N-glycolylneuraminic acid (Neu4Ac5Gc) -containing α2-3-sialosides have also been synthesized in the preparative scale. Used as an effective probe, Neu4,5Ac2α3GalβpNP was found to be a suitable substrate by human influenza A viruses but not bacterial sialidases.