2-Methyl-4-trifluoro­meth­yl-1,3-thia­zole-5-carboxylic acid

In crystal of the title compound, C6H4F3NO2S, mol­ecules are linked by O—H⋯N and C—H⋯O hydrogen bonds, forming chains

Allele frequency analysis of Chinese chestnut (Castanea mollissima) populations using fluorescent simple sequence repeats (SSR) analysis

The aim of this study was to establish a method for allele frequency detection in bulk samples. The abundance of polymerase chain reaction (PCR) products in bulk leaf samples was detected using fluorescent labeled Simple sequence repeat (SSR) primers and an Applied biosystems (AB) automatic DNA analyzer. Compared with the conventional SSR technique based on polyacrylamide gel electrophoresis (PAGE) and silver staining, fluorescent SSR was much more sensitive. A total of 78 alleles, an average of 4.6 alleles per locus, were detected among 17 chestnut populations with the primer CmTCR10 (NED) and a total of 41 alleles, an average of 2.4 alleles per locus, were detected with the primer CmTCR24 (6-FAM). Multiplexing the PCR reaction by combining the primer pairs of CmTCR10 and CmTCR24, using different fluorescent dyes for different primers, showed that the alleles could be discriminated and the sizes of the amplified segments were similar. Furthermore, the exact sizes of the amplified fragments and the abundance of the PCR products were determined by fluorescent SSR. After data analysis with GeneScan software and allele calling and output with Genotyper software, allele frequencies were calculated for equal pooled samples in each population using the FREQS-R module in the R statistical computing language. The results indicate that it is feasible to determine allele frequencies in bulked samples based on the detection of SSR-PCR products. The advantages and additional applications of this method are also discussed. The abundance of the PCR products can be used to determine the allele frequencies in bulk samples of chestnut populations.Keywords: Fluorescent simple sequence repeats (SSR), chestnut population, bulk sampling, allele frequencie

Pre-hypoxia exposure inhibited copper toxicity by improving energy metabolism, antioxidant defence and mitophagy in the liver of the large yellow croaker Larimichthys crocea

Abstract(#br)This study investigated the effects of moderate hypoxia pre-exposure on energy metabolism, antioxidant defence and mitophagy in the liver of the large yellow croaker Larimichthys crocea exposed to Cu. Fish were pre-exposed to either normoxia or hypoxia (~3.0 mg L −1 , 42% O 2 saturation) for 48 h, and subsequently were subjected to either control (without Cu addition) or Cu (168 μg L −1 ) under normoxic conditions for another 48 h. Copper exposure under normoxia induced Cu toxicity that increased mortality, the production of reactive oxygen species (ROS) and malondialdehyde, and aberrant hepatic mitochondrial ultrastructure. Interestingly, hypoxia pre-exposure improved energy metabolism, antioxidant ability and mitophagy response, and reduced the Cu content to inhibit Cu toxicity, reflecting the enhanced survival rate and reduced oxidative damage. In these processes, hypoxia-inducible factor-1α ( HIF-1α ), transcription factors NFE2-related nuclear factor 2 ( Nrf2 ), and forkhead box O-3 ( FoxO3 ) mRNA levels were correlated with expression of genes related to energy metabolism, antioxidant defence and mitophagy, respectively, indicating HIF-1α , Nrf2 , and FoxO3 are required for the induction of their respective target genes. Overall, moderate hypoxia pre-exposure was able to generate adaptive responses to mitigate Cu-induced toxicological effects, underlining a central role of hormesis

Pre-hypoxia exposure inhibited copper toxicity by improving energy metabolism, antioxidant defence and mitophagy in the liver of the large yellow croaker Larimichthys crocea.

This study investigated the effects of moderate hypoxia pre-exposure on energy metabolism, antioxidant defence and mitophagy in the liver of the large yellow croaker Larimichthys crocea exposed to Cu. Fish were pre-exposed to either normoxia or hypoxia (~3.0 mg L-1, 42% O2 saturation) for 48 h, and subsequently were subjected to either control (without Cu addition) or Cu (168 μg L-1) under normoxic conditions for another 48 h. Copper exposure under normoxia induced Cu toxicity that increased mortality, the production of reactive oxygen species (ROS) and malondialdehyde, and aberrant hepatic mitochondrial ultrastructure. Interestingly, hypoxia pre-exposure improved energy metabolism, antioxidant ability and mitophagy response, and reduced the Cu content to inhibit Cu toxicity, reflecting the enhanced survival rate and reduced oxidative damage. In these processes, hypoxia-inducible factor-1α (HIF-1α), transcription factors NFE2-related nuclear factor 2 (Nrf2), and forkhead box O-3 (FoxO3) mRNA levels were correlated with expression of genes related to energy metabolism, antioxidant defence and mitophagy, respectively, indicating HIF-1α, Nrf2, and FoxO3 are required for the induction of their respective target genes. Overall, moderate hypoxia pre-exposure was able to generate adaptive responses to mitigate Cu-induced toxicological effects, underlining a central role of hormesis

Channel Measurements and Models for High-Speed Train Communication Systems: A Survey

The recent development of high-speed trains (HSTs) as an emerging high mobility transportation system, and the growing demands of broadband services for HST users, introduce new challenges to wireless communication systems for HSTs. Accurate and efficient channel models considering both large-scale and non-stationary small-scale fading characteristics are crucial for the design, performance evaluation, and parameter optimization of HST wireless communication systems. However, the characteristics of the underlying HST channels have not yet been sufficiently investigated. This paper first provides a comprehensive review of the measurement campaigns conducted in different HST scenarios and then addresses the recent advances in HST channel models. Finally, key challenges of HST channel measurements and models are discussed and several research directions in this area are outlined

Cu pre-exposure alters antioxidant defense and energy metabolism in large yellow croaker Larimichthys crocea in response to severe hypoxia

Abstract(#br)The aim of the present study was to evaluate the effects of Cu pre-exposure on antioxidant defense and energy metabolism in the liver of the large yellow croaker exposed to severe hypoxia. Fish were pre-acclimated to 0 and 30 μg Cu L −1 for 96 h, and subsequently exposed to 7.0 and 1.5 mg DO L −1 for another 24 h. Hypoxic stress alone increased reactive oxygen species and hepatic vacuoles. When compared to hypoxic stress alone, hypoxic stress plus Cu pre-exposure increased mortality and ROS production, and worsened histological structure by inhibiting antioxidant defense and aerobic metabolism, and enhancing anaerobic metabolism, suggesting Cu pre-acclimation aggravated hypoxia-induced oxidative damage. NFE2-related nuclear factor 2 and hypoxia-inducible factor-1α might participate in the transcriptional regulation of genes related to antioxidant response and energy metabolism, respectively. In conclusion, Cu pre-acclimation had a synergistic effect on antioxidant response and energy metabolism in fish under severe hypoxia, which contributes to understanding the molecular mechanisms underlying negative effects of Cu pre-acclimation against hypoxic damage in fish