94 research outputs found

    DNA barcoding for the identification of common economic aquatic products in Central China and its application for the supervision of the market trade

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    Common economic aquatic products are important contributors to the human food supply. However, with the rapid globalization of the aquatic products industry, aquatic products market has become increasingly disordered. Therefore, an accurate and convenient method for identifying common economic aquatic products is important and necessary in many areas. DNA barcoding, which constitutes the analysis of a short fragment of the mitochondrial cytochrome c oxidase subunit I (COI) sequence, has been widely used in species identification. To discriminate common economic aquatic species using DNA barcoding, we collected 534 COI barcode sequences of 66 common species consisting of 39 fish, 9 crustaceans and 18 mollusks. The intraspecific genetic distances based on the Kimura 2-parameter (K2P) model were less than 1.37% for fish, 7.32% for crustaceans and 3.40% for mollusks, whereas the intragenus distances ranged from 3.91% to 13.82% for fish, 14.99%-16.17% for crustaceans and 14.82%-1636% for mollusks. The average intraspecific K2P distance was also compared with the average intragenus distance. The taxonomic resolution ratio values obtained for fish, crustaceans and mollusks were 58.50, 21.59 and 27.63 respectively, which are higher than the threshold of (10 x). A neighbor-joining (NJ) tree based on the K2P distance, and a maximum likelihood (ML) tree, based on the GTR + I + G model, were constructed, and all of the species could be identified unambiguously in the trees with several branches exhibiting high bootstrap values. Our results demonstrated high efficiency of DNA barcoding as an efficient molecular tool for the identification of common economic aquatic products, and 8 substitute species were successfully detected in 66 species. Our analyses also indicated that the common aquatic products trade industry could be effectively monitored and managed by DNA barcoding. Therefore, a simple identification database of common economic aquatic products was constructed. (C) 2015 Published by Elsevier Ltd

    Q-Switched 2 Micron Solid-State Lasers and Their Applications

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    In this chapter, we overview the Q-switched 2 μm solid-state laser development achieved in recent years, including flash- and diode-pumped solid-state lasers based on active and passive modulators. In summary, active Q-switching is still the first choice for obtaining large pulse energy at 2 μm currently, while passive Q-switching based on saturable absorbers (SAs), especially the newly emerging broadband low-dimension nanomaterial, is becoming promising approach in generating Q-switched 2 μm lasers specially with high repetition rate, although the output power, pulse duration, and pulse energy needs further enhancement. Besides, some important applications of 2 μm lasers, such as medicine, laser radar, and infrared directional interference, have also been introduced in brief

    Case report: Unusual cause of refractory hypoxemia after pacemaker lead extraction

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    A 59-year-old woman with a history of a pacemaker implanted for III-degree atrioventricular block was admitted due to pocket infection. The atrial and ventricular leads were removed via the right femoral vein using a needle's eye snare. Hypoxemia was observed immediately after the removal of the lead. It was refractory to oxygen therapy. The pulse oxygen saturation (SpO2) showed 89% in the supine position and 77% in the upright position. However, the CTPA and pulmonary perfusion SPECT/CT imaging did not reveal any signs of pulmonary embolism. Pulmonary function tests and chest CT showed normal results. Transthoracic contrast echocardiography revealed a patent foramen ovale (PFO) and a right-to-left intracardiac shunt, no significant tricuspid regurgitation, without any signs of elevated right heart pressure or pulmonary hypertension. Hypoxemia was considered to be associated with the right-to-left shunt through PFO. The condition was relieved by percutaneous closure of the PFO. Refractory hypoxemia resulting from an intracardiac right-to-left shunt following pacemaker lead extraction is a rare but serious complication. Transthoracic contrast echocardiography helps in diagnosis. If the right-to-left intracardiac shunt through PFO persists irreversibly and the associated hypoxemic symptoms are significant, closure of the PFO is necessary. Transesophageal echocardiography also revealed the presence of a left-to-right shunt through PFO during cardiac systole. The closure of the PFO is also necessary to avoid long-term complications, such as chronic pulmonary hypertension and right heart failure

    Tripartite motif containing 28 (TRIM28) promotes breast cancer metastasis by stabilizing TWIST1 protein.

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    TRIM28 regulates its target genes at both transcriptional and posttranscriptional levels. Here we report that a TRIM28-TWIST1-EMT axis exists in breast cancer cells and TRIM28 promotes breast cancer metastasis by stabilizing TWIST1 and subsequently enhancing EMT. We find that TRIM28 is highly expressed in both cancer cell lines and advanced breast cancer tissues, and the levels of TRIM28 and TWIST1 are positively correlated with the aggressiveness of breast carcinomas. Overexpression and depletion of TRIM28 up- and down-regulates the protein, but not the mRNA levels of TWIST1, respectively, suggesting that TRIM28 upregulates TWIST1 post-transcriptionally. Overexpression of TRIM28 in breast cancer cell line promotes cell migration and invasion. Knockdown of TRIM28 reduces the protein level of TWIST1 with concurrent upregulation of E-cadherin and downregulation of N-cadherin and consequently inhibits cell migration and invasion. Furthermore, Immunoprecipitation and GST pull-down assays demonstrated that TRIM28 interacts with TWIST1 directly and this interaction is presumed to protect TWIST1 from degradation. Our study revealed a novel mechanism in breast cancer cells that TRIM28 enhances metastasis by stabilizing TWIST1, suggesting that targeting TRIM28 could be an efficacious strategy in breast cancer treatment

    Population genetics analysis of the Nujiang catfish Creteuchiloglanis macropterus through a genome-wide single nucleotide polymorphisms resource generated by RAD-seq

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    Advances in genome scanning using high-throughput sequencing technologies has led to a revolution in studies of non-model organisms. The glyptosternoid fish Creteuchiloglanis macropterus, is widely distributed in the main stem and tributaries of the Nujiang River basin. Here, we analyzed IIB restriction-site-associated DNA (2b-RAD) sequences and mitochondrial DNA sequences, to assess the genomic signature of adaptation by detecting and estimating the degree of genetic differentiation among ten Creteuchiloglanis macropterus populations from the Nujiang River. The analyses revealed significant population differentiation among the up-tributaries, main stem, mid-tributary and low-tributary. Annotation of contigs containing outlier SNPs revealed that the candidate genes showed significant enrichment in several important biological process terms between up-tributaries and low-tributary, and exhibited prominent enrichment in the term macromolecular metabolic process between all tributaries and the main stem. Population dynamics analyses indicated that the Late Pleistocene glaciations strongly influenced the demographic history of C. macropterus. Our results provide strong evidence for the utility of RAD-seq in population genetics studies, and our generated SNP resource should provide a valuable tool for population genomics studies of C. macropterus in the future.</p

    Biogeographic history and high-elevation adaptations inferred from the mitochondrial genome of Glyptosternoid fishes (Sisoridae, Siluriformes) from the southeastern Tibetan Plateau

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    Background: The distribution of the Chinese Glyptosternoid catfish is limited to the rivers of the Tibetan Plateau and peripheral regions, especially the drainage areas of southeastern Tibet. Therefore, Glyptosternoid fishes are ideal for reconstructing the geological history of the southeastern Tibet drainage patterns and mitochondrial genetic adaptions to high elevations.</p

    An improved numerical model for epidemic transmission and infection risks assessment in indoor environment

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    Social distance will remain the key measure to contain COVID-19 before the global widespread vaccination coverage expected in 2024. Containing the virus outbreak in the office is prioritised to relieve socio-economic burdens caused by COVID-19 and potential pandemics in the future. However, “what is the transmissible distance of SARS-CoV-2” and “what are the appropriate ventilation rates in the office” have been under debate. Without quantitative evaluation of the infection risk, some studies challenged the current social distance policies of 1–2 m adopted by most countries and suggested that longer social distance rule is required as the maximum transmission distance of cough ejected droplets could reach 3–10 m. With the emergence of virus variants such as the Delta variant, the applicability of previous social distance rules are also in doubt. To address the above problem, this study conducted transient Computational Fluid Dynamics (CFD) simulations to evaluate the infection risks under calm and wind scenarios. The calculated Social Distance Index (SDI) indicates that lower humidity leads to a higher infection risk due to weaker evaporation. The infection risk in office was found more sensitive to social distance than ventilation rate. In standard ventilation conditions, social distance of 1.7 m–1.8 m is sufficient distances to reach low probability of infection (PI) target in a calm scenario when coughing is the dominant transmission route. However in the wind scenario (0.25 m/s indoor wind), distance of 2.8 m is required to contain the wild virus type and 3 m is insufficient to contain the spread of the Delta variant. The numerical methods developed in this study provide a framework to evaluate the COVID-19 infection risk in indoor environment. The predicted PI will be beneficial for governments and regulators to make appropriate social-distance and ventilation rules in the office
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