Quick freezing of rat morulae and blastocysts was attempted after they were dehydrated at room temperature. Combined solutions of 2.8 M glycerol and 0.125, 0.25, 0.50 and 1.0 M sucrose in phosphate buffered saline + 20% steer serum were compared. Survival rates (expanding blastocysts 15 h after thawing) were 42.1, 79.4, 87.5 and 16.7%, respectively (P<0.01). Freezing procedures consisted of either a direct plunge into liquid nitrogen (48.8%), holding for 5 min in the neck of a liquid nitrogen container or holding the samples for 60 min at -30 degrees C before insertion into liquid nitrogen. The direct plunge method resulted in a lower survival rate than either the 5- or the 60-min treatments (48.8% vs 76.9% and 77.6%, respectively). After thawing, dilution at room temperature in sucrose solutions of 0.25, 0.50 and 1.0 M gave survival rates of 80.0, 90.6 and 69.4%, respectively (NS). If diluted directly in PBS + 20% steer serum, 86.8% of embryos survived at +37 degrees C vs 0% at 0 degrees C (P<0.01).
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Langmuir
January 2025
Department of Chemistry, SUNY Buffalo State University, 1300 Elmwood Ave., Buffalo, New York 14222, United States.
Here, we report a simple method to prepare near-IR (NIR) surface-enhanced Raman scattering (SERS) substrates by quickly freezing a citrate-capped Au nanoparticle (AuNP) solution in liquid nitrogen, followed by thawing it at room temperature. This process aggregates AuNPs in a controlled manner by forming ice crystals with smaller grain sizes when compared to a slow freezing process. The resulting smaller AuNP aggregates remain suspended in solution long enough to conduct high-throughput chemical analysis in a microwell plate using the NIR SERS spectroscopy.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, Shandong, 266237, China. Electronic address:
Background: The COVID-19 pandemic has significantly affected global health, economies, and societies, and highlighted the urgent need for rapid, sensitive, affordable, and portable diagnostic devices for respiratory diseases, especially in areas with limited resources. In recent years, there has been rapid development in integrated equipments using microfluidic chips and biochemical detection technologies. However, these devices are expensive and complex to operate, showing limited feasibility for in point of care tests (PoCTs).
View Article and Find Full Text PDFACS Omega
December 2024
China Second Metallurgy Group Corporation Limited, Baotou, Inner Mongolia 014031, China.
Cell Biochem Funct
December 2024
Institute of Biochemistry and Department of Biology, Carleton University, Ottawa, Ontario, Canada.
The wood frog (Rana sylvatica) endures whole-body freezing over the winter, with extensive extracellular ice formation and halted physiological activities. Epigenetic mechanisms, including reversible histone lysine methylation, enable quick alterations in gene expression, helping to maintain viability during freeze-thaw cycles. The present study evaluated eight histone lysine methyltransferases (KMTs), 10 histone lysine demethylases (KDMs), and 11 histone marks in wood frog kidneys.
View Article and Find Full Text PDFLife Sci Alliance
March 2025
Institute of Medical Psychology and Biomedical Center (BMC), Faculty of Medicine, LMU, Munich, Germany
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