The stability of biological samples is vital for reliable measurements of biomarkers in large-scale survey settings, which may be affected by freeze-thaw procedures. We examined the effect of a single freeze-thaw cycle on 13 nutritional, noncommunicable diseases (NCD), and inflammatory bioanalytes in serum samples. Blood samples were collected from 70 subjects centrifuged after 30 minutes and aliquoted immediately. After a baseline analysis of the analytes, the samples were stored at - 70°C for 1 month and reanalyzed for all the parameters. Mean percentage differences between baseline (fresh blood) and freeze-thaw concentrations were calculated using paired sample -tests and evaluated according to total allowable error (TEa) limits (desirable bias). Freeze-thaw concentrations differed significantly ( < 0.05) from baseline concentrations for soluble transferrin receptor (sTfR) (- 5.49%), vitamin D (- 12.51%), vitamin B12 (- 3.74%), plasma glucose (1.93%), C-reactive protein (CRP) (3.45%), high-density lipoprotein (HDL) (7.98%), and cholesterol (9.76%), but they were within respective TEa limits. Low-density lipoprotein (LDL) (- 0.67%), creatinine (0.94%), albumin (0.87%), total protein (1.00%), ferritin (- 0.58%), and triglycerides (TAG) (2.82%) concentrations remained stable following the freeze-thaw cycle. In conclusion, single freeze-thaw cycle of the biomarkers in serum/plasma samples after storage at - 70°C for 1 month had minimal effect on stability of the studied analytes, and the changes in concentration were within acceptable limit for all analytes.
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http://dx.doi.org/10.1055/s-0041-1726575 | DOI Listing |
Plant Physiol Biochem
December 2024
Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), National Ethnic Affairs Commission, Beijing, 100081, China; Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing, 100081, China; College of Life and Environmental Sciences, Minzu University of China, Beijing, 100081, China. Electronic address:
Chitinases are enzymes that hydrolyze β-1,4-glycosidic bonds in chitin. Previous studies have shown that several chitinases accumulated significantly in A. mongolicus, suggesting that chitinases might participate in the adaptation to winter climate in Ammopiptanthus mongolicus.
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December 2024
State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Laboratory for Marine Drugs and Bioproducts, Qingdao Marine Science and Technology Centre, Qingdao 266237, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China. Electronic address:
Temperature fluctuations can negatively affect the quality of frozen shrimp. Research on novel cryoprotectants to replace traditional agents (phosphate, etc.) has become a hotspot.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Civil and Smart Construction Engineering, Shantou University, Shantou, 515063, Guangdong, China.
Saline soil is widely distributed in China and poses significant challenges to engineering construction due to its harmful effects, such as salt heaving, dissolution collapse, and frost heaving. The Microbial-Induced Calcite Precipitation (MICP) method is an emerging environmental-friendly modification that can reduce or eliminate the environmental and engineering hazards of saline soil. To verify the feasibility of the MICP method for improving the properties of saline soil, laboratory tests were conducted to study the effects of salt content, activated carbon content and freeze-thaw cycles on the compression and water retention behavior of MICP modified saline soil.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Mechanics, Xi'an University of Science and Technology, Xi'an, 710054, China.
Under confining pressure, rocks transition from brittle failure to plastic failure, and residual strength exists after complete failure. However, in the process of establishing rock damage constitutive models, the strength criteria used usually do not consider residual stress. In cold region engineering, the freeze-thaw effect caused by temperature changes should be considered in the constitutive model, and strength criteria should also be introduced.
View Article and Find Full Text PDFPLoS One
December 2024
Civil Engineering Department, Lanzhou Jiaotong University, Lanzhou, China.
The Belt and Road strategy has significantly advanced the scale of infrastructure construction in the Qinghai-Tibet Plateau permafrost area. Consequently, this demands higher requirements on the strength and frost resistance of concrete (FRC) cured under low-temperature and negative-temperature conditions. Accordingly, in this study, tests on the mechanical properties and FRC were conducted under standard curing, 5 °C curing, and -3 °C curing conditions.
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