169 research outputs found

    Raw frozen Antarctic krill (Euphausia superba) as an alternative feed source for cuttlefish Sepiella japonica in artificial breeding systems

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    The study aims to evaluate the feasibility of completely replacing raw frozen shrimp Palaemon gravieri diets with raw frozen Antarctic krill (Euphausia superba) in the diets of cuttlefish Sepiella japonica. To address the knowledge gap, we conducted a 60‐day feeding trial. At the end of the experiment (day 60), the cuttlefish Sepiella japonica eating Palaemon gravieri (SJP) grew significantly faster than those eating Euphausia superba (SJE), with the specific growth rate (SGR)SJP (7.92%) > (SGR)SJE (7.09%). Approximately 33.3% and 20.0% mortality was observed in the SJE and SJP, during the course of the experiment respectively. Some important fatty acids (i.e. n‐3 and n‐6 PUFAs) were elevated in SJE with respect to SJP. Replacement of Antarctic krill increased the diversity of the gut microbiome composition in the SJE group. Fluoride accumulated in the ink sac and cuttlebone of cuttlefish in SJE. Overall, these findings imply that PUFA‐rich Antarctic krill could replace P. gravieri shrimp for feeding cuttlefish S. japonica

    DNA barcoding of Antarctic marine zooplankton for species identification and recognition

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    Polar zooplankton are particularly sensitive to climate change, and have been used as rapid-responders to indicate climate-induced changes in the fragile Antarctic ecosystem. DNA barcoding provides an alternative approach for rapid zooplankton species identification. Ninety-four specimens belonging to 32 Antarctic zooplankton species were barcoded to construct a comprehensive reference library. An 830 to 1 050 base-pair region of the mitochondrial cytochrome c oxidase subunit I (mtCOI) gene was obtained as DNA barcodes. The intraspecific variation of the gene ranged from 0 to 2.6% (p-distance), with an average of 0.67% (SD=0.67%). The distance between species within the same genera ranged from 0.1% (Calanus) to 29.3%, with an average of 15.3% (SD=8.4%). The morphological and genetic similarities between Calanus propinquus and C. simillimus raise new questions about the taxonomic status of C. simillimus. With the exception of the two Calanus species, the intraspecific genetic divergence was much smaller than the interspecific divergence among congeneric species, confirming the existence of a barcode gap for Antarctic zooplankton. In addition, species other than Calanus sp. formed a monophyletic group. Therefore, we have confirmed DNA barcoding as an accurate and efficient approach for zooplankton identification in the Antarctic area (except for Hydromedusa, Tunicata, and other gelatinous zooplankton). Indicator vector analysis further confirmed this conclusion. The new primer sets issued here may facilitate the study of Antarctic marine zooplankton species composition by environmental metagenetic analysis

    Carbonaceous matter in the atmosphere and glaciers of the Himalayas and the Tibetan plateau: An investigative review

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    Carbonaceous matter, including organic carbon (OC) and black carbon (BC), is an important climate forcing agent and contributes to glacier retreat in the Himalayas and the Tibetan Plateau (HTP). The HTP – the so-called “Third Pole” – contains the most extensive glacial area outside of the polar regions. Considerable research on carbonaceous matter in the HTP has been conducted, although this research has been challenging due to the complex terrain and strong spatiotemporal heterogeneity of carbonaceous matter in the HTP. A comprehensive investigation of published atmospheric and snow data for HTP carbonaceous matter concentration, deposition and light absorption is presented, including how these factors vary with time and other parameters. Carbonaceous matter concentrations in the atmosphere and glaciers of the HTP are found to be low. Analysis of water-insoluable organic carbon and BC from snowpits reveals that concentrations of OC and BC in the atmosphere and glacier samples in arid regions of the HTP may be overestimated due to contributions from inorganic carbon in mineral dust. Due to the remote nature of the HTP, carbonaceous matter found in the HTP has generally been transported from outside the HTP (e.g., South Asia), although local HTP emissions may also be important at some sites. This review provides essential data and a synthesis of current thinking for studies on atmospheric transport modeling and radiative forcing of carbonaceous matter in the HTP

    Case report: A longitudinal study of an unusual rapidly progressive dementia case

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    It is daunting to determine the etiology of rapidly progressive dementia (RPD), which includes metabolic, neoplastic, infectious, autoimmune, neurodegenerative and other conditions. Herein, we illustrate an unusual case of a patient primarily exhibiting RPD, overlapping sleep dysfunction, psychosis and abnormal movement, which was finally defined as anti-IgLON5 disease, a novel and rare autoimmune encephalopathy. Furthermore, we longitudinally described his cognitive and psychological performance in detail, and determined that early initiation of immunotherapy in this patient did not result in a good outcome. These data highlight anti-IgLON5 disease as a possible differential diagnosis in patients with RPD

    Dislocation toughening in single‐crystal KNbO₃

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    The growing research interest in dislocation‐tuned functionality in ceramics is evident, with the most recent proofs‐of‐concept for enhanced ferroelectric properties, electrical conductivity, and superconductivity via dislocations. In this work, we focus on dislocation‐tuned mechanical properties and demonstrate that, by engineering high dislocation densities (up to 10¹⁴ m⁻²) into KNbO₃ at room temperature, the fracture toughness can be improved by a factor of 2.8. The microstructures, including dislocations and domain walls, are examined by optical microscopy, electron channeling contrast imaging, piezo‐response force microscopy, and transmission electron microscopy methods to shed light on the toughening mechanisms. In addition, high‐temperature (above the Curie temperature of KNbO₃) indentation tests were performed to exclude the influence of ferroelastic toughening, such that the origin of the toughening effect is pinpointed to be dislocations

    Regression of Gastric Cancer by Systemic Injection of RNA Nanoparticles Carrying Both Ligand and siRNA

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    Gastric cancer is the second leading cause of cancer-related death worldwide. RNA nanotechnology has recently emerged as an important field due to recent finding of its high thermodynamic stability, favorable and distinctive in vivo attributes. Here we reported the use of the thermostable three-way junction (3WJ) of bacteriophage phi29 motor pRNA to escort folic acid, a fluorescent image marker and BRCAA1 siRNA for targeting, imaging, delivery, gene silencing and regression of gastric cancer in animal models. In vitro assay revealed that the RNA nanoparticles specifically bind to gastric cancer cells, and knock-down the BRCAA1 gene. Apoptosis of gastric cancer cells was observed. Animal trials confirmed that these RNA nanoparticles could be used to image gastric cancer in vivo, while showing little accumulation in crucial organs and tissues. The volume of gastric tumors noticeably decreased during the course of treatment. No damage to important organs by RNA nanoparticles was detectible. All the results indicated that this novel RNA nanotechnology can overcome conventional cancer therapeutic limitations and opens new opportunities for specific delivery of therapeutics to stomach cancer without damaging normal cells and tissues, reduce the toxicity and side effect, improve the therapeutic effect, and exhibit great potential in clinical tumor therapy

    Inducible T-Cell Co-Stimulator Impacts Chronic Graft-Versus-Host Disease by Regulating Both Pathogenic and Regulatory T Cells

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    The incidence of chronic graft-versus-host disease (cGVHD) is on the rise and still the major cause of morbidity and mortality among patients after allogeneic hematopoietic stem cell transplantation (HCT). Both donor T and B cells contribute to the pathogenesis of cGVHD. Inducible T-cell co-stimulator (ICOS), a potent co-stimulatory receptor, plays a key role in T-cell activation and differentiation. Yet, how ICOS regulates the development of cGVHD is not well understood. Here, we investigated the role of ICOS in cGVHD pathogenesis using mice with germline or regulatory T cell (Treg)-specific ICOS deficiency. The recipients of ICOS−/− donor grafts had reduced cGVHD compared with wild-type controls. In recipients of ICOS−/− donor grafts, we observed significant reductions in donor T follicular helper (Tfh), Th17, germinal center B-cell, and plasma cell differentiation, coupled with lower antibody production. Interestingly, Tregs, including follicular regulatory T (Tfr) cells, were also impaired in the absence of ICOS. Using ICOS conditional knockout specific for Foxp3+ cells, we found that ICOS was indispensable for optimal survival and homeostasis of induced Tregs during cGVHD. Furthermore, administration of anti-ICOS alleviated cGVHD severity via suppressing T effector cells without affecting Treg generation. Taken together, ICOS promotes T- and B-cell activation and differentiation, which can promote cGVHD development; however, ICOS is critical for the survival and homeostasis of iTregs, which can suppress cGVHD. Hence, ICOS balances the development of cGVHD and could offer a potential target after allo-HCT in the clinic

    Black carbon and organic carbon dataset over the Third Pole

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    The Tibetan Plateau and its surroundings, also known as the Third Pole, play an important role in the global and regional climate and hydrological cycle. Carbonaceous aerosols (CAs), including black carbon (BC) and organic carbon (OC), can directly or indirectly absorb and scatter solar radiation and change the energy balance on the Earth. CAs, along with the other atmospheric pollutants (e.g., mercury), can be frequently transported over long distances into the inland Tibetan Plateau. During the last decades, a coordinated monitoring network and research program named “Atmospheric Pollution and Cryospheric Changes” (APCC) has been gradually set up and continuously operated within the Third Pole regions to investigate the linkage between atmospheric pollutants and cryospheric changes. This paper presents a systematic dataset of BC, OC, water-soluble organic carbon (WSOC), and water-insoluble organic carbon (WIOC) from aerosols (20 stations), glaciers (17 glaciers, including samples from surface snow and ice, snow pits, and 2 ice cores), snow cover (2 stations continuously observed and 138 locations surveyed once), precipitation (6 stations), and lake sediment cores (7 lakes) collected across the Third Pole, based on the APCC program. These data were created based on online (in situ) and laboratory measurements. High-resolution (daily scale) atmospheric-equivalent BC concentrations were obtained by using an Aethalometer (AE-33) in the Mt. Everest (Qomolangma) region, which can provide new insight into the mechanism of BC transportation over the Himalayas. Spatial distributions of BC, OC, WSOC, and WIOC from aerosols, glaciers, snow cover, and precipitation indicated different features among the different regions of the Third Pole, which were mostly influenced by emission sources, transport pathways, and deposition processes. Historical records of BC from ice cores and lake sediment cores revealed the strength of the impacts of human activity since the Industrial Revolution. BC isotopes from glaciers and aerosols identified the relative contributions of biomass and fossil fuel combustion to BC deposition on the Third Pole. Mass absorption cross sections of BC and WSOC from aerosol, glaciers, snow cover, and precipitation samples were also provided. This updated dataset is released to the scientific communities focusing on atmospheric science, cryospheric science, hydrology, climatology, and environmental science. The related datasets are presented in the form of excel files. BC and OC datasets over the Third Pole are available to download from the National Cryosphere Desert Data Center (10.12072/ncdc.NIEER.db0114.2021; Kang and Zhang, 2021)

    Simultaneous Detection of Major Drug Resistance Mutations in the Protease and Reverse Transcriptase Genes for HIV-1 Subtype C by Use of a Multiplex Allele-Specific Assay

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    High-throughput, sensitive, and cost-effective HIV drug resistance (HIVDR) detection assays are needed for large-scale monitoring of the emergence and transmission of HIVDR in resource-limited settings. Using suspension array technology, we have developed a multiplex allele-specific (MAS) assay that can simultaneously detect major HIVDR mutations at 20 loci. Forty-five allele-specific primers tagged with unique 24-base oligonucleotides at the 5′ end were designed to detect wild-type and mutant alleles at the 20 loci of HIV-1 subtype C. The MAS assay was first established and optimized with three plasmid templates (C-wt, C-mut1, and C-mut2) and then evaluated using 148 plasma specimens from HIV-1 subtype C-infected individuals. All the wild-type and mutant alleles were unequivocally distinguished with plasmid templates, and the limits of detection were 1.56% for K219Q and K219E, 3.13% for L76V, 6.25% for K65R, K70R, L74V, L100I, K103N, K103R, Q151M, Y181C, and I47V, and 12.5% for M41L, K101P, K101E, V106A, V106M, Y115F, M184V, Y188L, G190A, V32I, I47A, I84V, and L90M. Analyses of 148 plasma specimens revealed that the MAS assay gave 100% concordance with conventional sequencing at eight loci and >95% (range, 95.21% to 99.32%) concordance at the remaining 12 loci. The differences observed were caused mainly by 24 additional low-abundance alleles detected by the MAS assay. Ultradeep sequencing analysis confirmed 15 of the 16 low-abundance alleles. This multiplex, sensitive, and straightforward result-reporting assay represents a new efficient genotyping tool for HIVDR surveillance and monitoring
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