38 research outputs found
The <i>Sinocyclocheilus</i> cavefish genome provides insights into cave adaptation
BACKGROUND: An emerging cavefish model, the cyprinid genus Sinocyclocheilus, is endemic to the massive southwestern karst area adjacent to the Qinghai-Tibetan Plateau of China. In order to understand whether orogeny influenced the evolution of these species, and how genomes change under isolation, especially in subterranean habitats, we performed whole-genome sequencing and comparative analyses of three species in this genus, S. grahami, S. rhinocerous and S. anshuiensis. These species are surface-dwelling, semi-cave-dwelling and cave-restricted, respectively. RESULTS: The assembled genome sizes of S. grahami, S. rhinocerous and S. anshuiensis are 1.75 Gb, 1.73 Gb and 1.68 Gb, respectively. Divergence time and population history analyses of these species reveal that their speciation and population dynamics are correlated with the different stages of uplifting of the Qinghai-Tibetan Plateau. We carried out comparative analyses of these genomes and found that many genetic changes, such as gene loss (e.g. opsin genes), pseudogenes (e.g. crystallin genes), mutations (e.g. melanogenesis-related genes), deletions (e.g. scale-related genes) and down-regulation (e.g. circadian rhythm pathway genes), are possibly associated with the regressive features (such as eye degeneration, albinism, rudimentary scales and lack of circadian rhythms), and that some gene expansion (e.g. taste-related transcription factor gene) may point to the constructive features (such as enhanced taste buds) which evolved in these cave fishes. CONCLUSION: As the first report on cavefish genomes among distinct species in Sinocyclocheilus, our work provides not only insights into genetic mechanisms of cave adaptation, but also represents a fundamental resource for a better understanding of cavefish biology. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12915-015-0223-4) contains supplementary material, which is available to authorized users
Ultrasonic Cavitation Erosion Behavior of AlCoCrxCuFe High Entropy Alloy Coatings Synthesized by Laser Cladding
Cavitation corrosion resistant coatings are an excellent solution to the cavitation corrosion problem. High entropy alloys provide a new possibility for cavitation resistant coatings due to their excellent comprehensive performance. Laser cladding was employed to synthesize AlCoCrxCuFe (x represents the Cr concentration, x = 0.5, 1.0, 1.5, 2.0) high entropy alloy coatings (HECs) on AISI 304 steel. The phase transformation, microstructure, micro-mechanical properties, and cavitation erosion performance of HECs were studied. Results showed that AlCoCrxCuFe HECs were composed of BCC and FCC duplex phase. The microstructure of HECs showed a typical dendritic structure. The composition segregation of interdendrite structures was observed. Cavitation erosion resistance represented by 20 h volume loss was decreased with the increase in Cr content. AlCoCrxCuFe HECs with the lowest chromium content (AlCoCr0.5CuFe) showed the best cavitation erosion resistance among all samples. The cavitation resistance of AlCoCrxCuFe HECs has good correlation with the mechanical parameter Hn3/Er2 (Hn is nanohardness, Er is elastic modulus) and phase formation parameter δ (δ is atomic radius difference). The surface after 20 h of cavitation erosion testing exposed the dendritic structure of BCC phase, which was caused by the destruction of the interdendrite structure by cavitation impact
Is Chemerin associated with gestational diabetes mellitus? An evidence-based clinical research from Chinese women
The present study aimed to explore the association between gestational diabetes mellitus (GDM) and Chemerin, by analysing Chemerin level, clinical data and biochemical parameters among 46 GDM patients and 43 controls. It was found that the Chemerin levels from cord blood, peripheral blood, adipose tissue and placenta tissue were all significantly higher in the GDM group than those in the control group (p < .05 for all). Maternal insulin resistance (IR) index and serum inflammation parameters, including C-reactive protein and white blood cells, were also higher in GDM group (p < .05 for all). Moreover, maternal IR index and circulating insulin level were both positively correlated with maternal circulating Chemerin level (p < .05 for both). Our findings suggest that Chemerin, associated with IR and more expressed in GDM women, might participate in the pathogenesis of GDM.Impact Statement What is already known on this subject: Chemerin, a recently-discovered adipocytokine, has been widely-considered to be involved in metabolic diseases, and several studies have investigated it in gestational diabetes mellitus (GDM), but with no consensus about the level comparison between GDM and controls. What the results of this study add: The present case-control study found that the levels of Chemerin from cord blood, peripheral blood, adipose tissue and placenta tissue were all significantly higher in the GDM group. What the implications are of these findings for clinical practice and/or further research: Also, the circulating Chemerin level was positively correlated with insulin index, which we thought would add to the evidence that Chemerin does be associated with GDM, contributing to elucidating the pathogenesis of GDM
K<sub>x</sub>Co<sub>1.5−0.5x</sub>Fe(CN)<sub>6</sub>/rGO with Dual−Active Sodium Ion Storage Site as Superior Anode for Sodium Ion Battery
The unique and open large frame structures of prussian blue analogues (PBA) enables it for accommodating a large number of cations (Na+, K+, Ca2+, etc.), thus, PBA are considered as promising electrode materials for the rechargeable battery. However, due to the chemical composition, there are still many alkaline metal ions in the gap within the framework, which puts multivalent metals in PBA in a low valence state and affects the sodium storage performance. To improve the valence of metal ions in PBA materials, precursors prepared by co−precipitation method and hydrothermal method are used to synthesis KxCo1.5−0.5xFe(CN)6 through further chemical oxidation. Through the introducing of reduced graphene oxide (rGO) with excellent conductivity by a simple physical mixing method, the cycle stability and rate performance of the PBA material can be further improved. The K0.5Co1.2Fe(CN)6·2H2O/rGO anode prepared with 2 h hydrothermal time and further chemical oxidation, named as KCoHCP−H2−EK/rGO, exhibits a super electrochemical performance, delivering initial charge/discharge capacities of 846.7/1445.0 mAh·g−1, and a capacity retention of 58.2% after 100 cycles at a current density of 100 mA·g−1. The KCoHCP−H2−EK/rGO outstanding electrochemical behaviors are attributed to the unique dual−active site structure properties and the improved surface conductance of materials by rGO components
Vinyl Phosphate-Functionalized, Magnetic, Molecularly-Imprinted Polymeric Microspheres’ Enrichment and Carbon Dots’ Fluorescence-Detection of Organophosphorus Pesticide Residues
The rapid detection of organophosphorus pesticide residues in food is crucial to food safety. One type of novel, magnetic, molecularly-imprinted polymeric microsphere (MMIP) was prepared with vinyl phosphate and 1-octadecene as a collection of dual functional monomers, which were screened by Gaussian09W molecular simulation. MMIPs were used to enrich organic phosphorus, which then detected by fluorescence quenching in vinyl phosphate-modified carbon dots (CDs@VPA) originated from anhydrous citric acid. MMIPs and CDs@VPA were characterized by TEM, particle size analysis, FT-IR, VSM, XPS, adsorption experiments, and fluorescence spectrophotometry in turn. Through the fitting data from experiment and Gaussian quantum chemical calculations, the molecular recognition properties and the mechanism of fluorescence detection between organophosphorus pesticides and CDs@VPA were also investigated. The results indicated that the MMIPs could specifically recognize and enrich triazophos with the saturated adsorption capacity 0.226 mmol g−1, the imprinting factor 4.59, and the limit of recognition as low as 0.0006 mmol L−1. Under optimal conditions, the CDs@VPA sensor has shown an extensive fluorescence property with a LOD of 0.0015 mmol L−1 and the linear range from 0.0035 mmol L−1 to 0.20 mmol L−1 (R2 = 0.9988) at 390 nm. The mechanism of fluorescence detection of organic phosphorus with CDs@VPA sensor might be attributable to hydrogen bonds formed between heteroatom O, N, S, or P, and the O−H group, which led to fluorescent quenching. Meanwhile, HN−C=O and Si−O groups in CDs@VPA system might contribute to cause excellent blue photoluminescence. The fluorescence sensor was thorough successfully employed to the detection of triazophos in cucumber samples, illustrating its tremendous value towards food sample analysis in complex matrix
Hydrogels with Dual Gradients of Mechanical and Biochemical Cues for Deciphering Cell-Niche Interactions
Cell niche is a multifactorial environment
containing complex interactions
between biochemical and physical cues. Although extensive studies
have examined the effects of biochemical or physical cues alone on
cell fate, how biochemical and mechanical signals interact to influence
cell fates remains largely unknown. To address this challenge, here
we report a polyethylene glycol-based gradient hydrogel platform as
biomimetic cell niche containing independently tunable matrix stiffness
and biochemical ligand density. The versatility of this platform is
demonstrated by fabricating and characterizing single gradient or
orthogonally aligned dual gradient hydrogels. These gradients result
in differential elongation and spreading of human fibroblasts. Both
hydrogel stiffness and biochemical ligand density are independently
tunable by sequential photopolymerization. By controlling light exposure,
a broad range of hydrogel stiffness and different types/doses of biochemical
ligands can be incorporated. Such tunability facilitates customization
of this platform for investigating complex cell-niche interactions
associated with various cell types, such as stem cells and cancer
cells. The outcomes of such studies may help identify optimal niche
cues to promote desiralbe stem fates and tissue regeneration or inhibit
diseases progression
Acute myeloid leukemia following remission of AIDS-associated extra-nodal NK/T-cell lymphoma
Background: AIDS-related NK/T-cell lymphoma is a rare subtype of AIDS-related lymphomas, characterized by a poor prognosis and lack of standardized treatment protocols. To date, there have been no reported cases of AIDS-associated NK/T-cell lymphoma in remission followed by treatment-related acute myeloid leukemia (t-AML), where both the lymphoma and AML achieved remission and long-term survival through chemotherapy alone. Case presentation: We report a case of a patient diagnosed with AIDS-related extra-nodal NK/T-cell lymphoma (ENKTCL). The patient achieved complete remission after receiving six cycles of chemotherapy, local radiotherapy, and combination antiretroviral therapy (cART). Throughout the follow-up period, the patient continued cART treatment, maintaining an HIV-RNA level below the lower limit of detection. However, 70 months later, the patient developed new symptoms and was subsequently diagnosed with acute myeloid leukemia (AML) M4 subtype. Following the completion of 10 cycles of chemotherapy and ongoing cART, the patient achieved complete remission of AML, with an overall survival time exceeding 103 months from the initial ENKTCL diagnosis. Conclusions: This case highlights the effectiveness of chemotherapy combined with cART in the treatment of AIDS-associated NK/T-cell lymphoma and secondary treatment-related leukemia. This approach may serve as a viable option for patients who are not candidates for bone marrow transplantation. Furthermore, this case underscores the importance of long-term follow-up in the management of AIDS-associated malignancies
Synthesis and Structure–Activity Relationship of Palmatine Derivatives as a Novel Class of Antibacterial Agents against Helicobacter pylori
Taking palmatine (PMT) as the lead, 20 new PMT derivatives were synthesized and examined for their antibacterial activities against six tested metronidazole (MTZ)-resistant Helicobacter pylori (H. pylori) strains. The structure–activity relationship (SAR) indicated that the introduction of a suitable secondary amine substituent at the 9-position might be beneficial for potency. Among them, compound 1c exhibited the most potent activities against MTZ-resistant strains, with minimum inhibitory concentration (MIC) values of 4–16 μg/mL, better than that of the lead. It also exhibited a good safety profile with a half-lethal dose (LD50) of over 1000 mg/kg. Meanwhile, 1c might exert its antimicrobial activity through targeting H. pylori urease. These results suggested that PMT derivatives might be a new family of anti-H. pylori components