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Simple Summary: A cryopreservation method for L. fulica germ cells was developed using vitrification. Key reproductive organs, including the ovotestis containing both male and female germ cells, were isolated. Vitrification technology was applied, resulting in 86.8% cell viability post-thawing compared to 96.6% in the non-vitrified group. This study establishes a reliable protocol for preserving L. fulica germ cells, with potential applications for conserving other endangered snail species. This study aims to develop an optimized method for cryopreserving the germ cells of Lissachatina fulica (L. fulica) using vitrification, as an alternative approach for conserving endangered snail species. First, we isolated several key reproductive organs, including the sperm oviduct, albumen gland, hermaphrodite gland (ovotestis), and hermaphrodite duct from L. fulica. When the ovotestis was finely chopped, numerous sperm with long tails and distinct heads were observed. The staining of sperm nuclei was confirmed using Hoechst 33342 dye. Since the hermaphrodite gland, referred to as the ovotestis, contains both male and female germ cells, we performed tissue staining on the ovotestis using hematoxylin and eosin (H&E) dye. H&E staining of the ovotestis revealed numerous oval-shaped acini containing sperm and early germ cells. Spermatocytes and spermatids were observed within distinct boundaries, with mature sperm appearing following spermatogenesis. To preserve the species of the L. fulica, we introduced vitrification technology to cryopreserve its reproductive organs. The non-vitrification group showed an average cell viability of 96.6%, while the vitrification group had 86.8% after thawing. This study presents a reliable cryopreservation protocol for L. fulica, with potential applications for other endangered snails, supporting conservation efforts to preserve genetic resources and biodiversity. [ABSTRACT FROM AUTHOR]

Background: The coronavirus disease (COVID‐19) pandemic significantly impacted medical care, including ophthalmology. This study aimed to identify factors associated with reduced ophthalmic medical access during the pandemic. Methods: This nationwide population‐based cohort study analysed South Korean health insurance claims data from January 2019 to November 2021. Outpatient visits and surgeries for age‐related macular degeneration, cataract, diabetic retinopathy, glaucoma, and retinal detachment during the two pandemic waves were compared with those in the non‐pandemic period. Poisson regression was used to estimate incidence rate ratios and changes in outpatient visits and surgeries between waves concerning patient age, sex, residential location, and health insurance type. Results: Outpatient visits for five eye diseases decreased in the first wave (0.733–0.985, P < 0.001). In the second wave, only outpatient visits for age‐related macular degeneration, cataract, and glaucoma decreased (0.754, 0.878, and 0.874, respectively, all P < 0.001). Age‐related macular degeneration, cataract, and glaucoma surgeries were significantly reduced in the first wave (0.829, P < 0.001; 0.836, P < 0.001; 0.904, P = 0.030, respectively). Age‐related macular degeneration (0.852) and cataract (0.716) surgeries dropped in the second wave. Women and elderly (>65 years) patients curtailed outpatient visits and surgeries more throughout the pandemic and were less resilient during the second wave. Wave location was also related to outpatient visits and surgeries. Conclusions: The COVID‐19 pandemic decreased outpatient visits and surgeries for eye diseases, with more significant impact on women, older patients, and those residing near wave locations. These findings can inform healthcare policies to minimise future pandemic impacts on healthcare delivery. [ABSTRACT FROM AUTHOR]

This study aims to develop an optimized method for cryopreserving the germ cells of Lissachatina fulica ( L. fulica ) using vitrification, as an alternative approach for conserving endangered snail species. First, we isolated several key reproductive organs, including the sperm oviduct, albumen gland, hermaphrodite gland (ovotestis), and hermaphrodite duct from L. fulica . When the ovotestis was finely chopped, numerous sperm with long tails and distinct heads were observed. The staining of sperm nuclei was confirmed using Hoechst 33342 dye. Since the hermaphrodite gland, referred to as the ovotestis, contains both male and female germ cells, we performed tissue staining on the ovotestis using hematoxylin and eosin (H&E) dye. H&E staining of the ovotestis revealed numerous oval-shaped acini containing sperm and early germ cells. Spermatocytes and spermatids were observed within distinct boundaries, with mature sperm appearing following spermatogenesis. To preserve the species of the L. fulica , we introduced vitrification technology to cryopreserve its reproductive organs. The non-vitrification group showed an average cell viability of 96.6%, while the vitrification group had 86.8% after thawing. This study presents a reliable cryopreservation protocol for L. fulica , with potential applications for other endangered snails, supporting conservation efforts to preserve genetic resources and biodiversity.

This study is the first to identify bovine blastocysts through in vitro fertilization (IVF) of matured oocytes with a large quantity of high-quality sperm separated from a biomimetic cervix environment. We obtained high-quality sperm in large quantities using an IVF sperm sorting chip (SSC), which could mimic the viscous environment of the bovine cervix during ovulation and facilitates isolation of progressively motile sperm from semen. The viscous environment-on-a-chip was realized by formulating and implementing polyvinylpyrrolidone (PVP)-based solutions for the SSC medium. Sperm separated from the IVF-SSC containing PVP 1.5% showed high motility, normal morphology and high DNA integrity. As a result of IVF, a higher rate of hatching blastocysts, which is the pre-implantation stage, were observed, compared to the conventional swim-up method. Our results may significantly contribute to improving livestock with superior male and female genetic traits, thus overcoming the limitation of artificial insemination based on the superior genetic traits of existing males.