49 research outputs found
AOSR-Net: All-in-One Sandstorm Removal Network
Most existing sandstorm image enhancement methods are based on traditional
theory and prior knowledge, which often restrict their applicability in
real-world scenarios. In addition, these approaches often adopt a strategy of
color correction followed by dust removal, which makes the algorithm structure
too complex. To solve the issue, we introduce a novel image restoration model,
named all-in-one sandstorm removal network (AOSR-Net). This model is developed
based on a re-formulated sandstorm scattering model, which directly establishes
the image mapping relationship by integrating intermediate parameters. Such
integration scheme effectively addresses the problems of over-enhancement and
weak generalization in the field of sand dust image enhancement. Experimental
results on synthetic and real-world sandstorm images demonstrate the
superiority of the proposed AOSR-Net over state-of-the-art (SOTA) algorithms.Comment: Accepted by The 35th IEEE International Conference on Tools with
Artificial Intelligence. (ICTAI 2023
A mechanism of glucose tolerance and stimulation of GH1 β-glucosidases
β-Glucosidases are enzymes that hydrolyze β-glycosidic bonds to release non-reducing terminal glucosyl residues from glycosides and oligosaccharides, and thus have significant application potential in industries. However, most β-glucosidases are feedback inhibited by the glucose product, which restricts their application. Remarkably, some β-glucosidases of the glycoside hydrolase (GH) 1 family are tolerant to or even stimulated by glucose. Elucidation of the mechanisms of glucose tolerance and stimulation of the GH1 β-glucosidases will be crucial to improve their application through enzyme engineering. In this study, by comparing the primary and tertiary structures of two GH1 β-glucosidases with distinct glucose dependence, some putative glucose-dependence relevant sites were mutated to investigate their exact roles. Both biochemical and structural characterization of the mutants suggested that some sites at the entrance and middle of the substrate channel regulate the effects of glucose, and the relative binding affinity/preference of these sites to glucose modulates the glucose dependence. A mechanism was therefore proposed to interpret the glucose dependence of GH1 β-glucosidases. This research provides fresh insight into our current understanding of the properties and mechanisms of GH1 β-glycosidases and related enzymes that modulate their activity via feedback control mechanism
Identification of a laccase Glac15 from Ganoderma lucidum 77002 and its application in bioethanol production
Background Laccases have potential applications in detoxification of lignocellulosic biomass after thermochemical pretreatment and production of value-added products or biofuels from renewable biomass. However, their application in large-scale industrial and environmental processes has been severely thwarted by the high cost of commercial laccases. Therefore, it is necessary to identify new laccases with lower cost but higher activity to detoxify lignocellulosic hydrolysates and better efficiency to produce biofuels such as bioethanol. Laccases from Ganoderma lucidum represent proper candidates in processing of lignocellulosic biomass. Results G. lucidum 77002 produces three laccase isoenzymes with a total laccase activity of 141.1 U/mL within 6 days when using wheat bran and peanut powder as energy sources in liquid culture medium. A new isoenzyme named Glac15 was identified, purified, and characterized. Glac15 possesses an optimum pH of 4.5 to 5.0 and a temperature range of 45°C to 55°C for the substrates tested. It was stable at pH values ranging from 5.0 to 7.0 and temperatures lower than 55°C, with more than 80% activity retained after incubation for 2 h. When used in bioethanol production process, 0.05 U/mL Glac15 removed 84% of the phenolic compounds in prehydrolysate, and the yeast biomass reached 11.81 (optimal density at 600 nm (OD600)), compared to no growth in the untreated one. Addition of Glac15 before cellulase hydrolysis had no significant effect on glucose recovery. However, ethanol yield were improved in samples treated with laccases compared to that in control samples. The final ethanol concentration of 9.74, 10.05, 10.11, and 10.81 g/L were obtained from samples containing only solid content, solid content treated with Glac15, solid content containing 50% prehydrolysate, and solid content containing 50% prehydrolysate treated with Glac15, respectively. Conclusions The G. lucidum laccase Glac15 has potentials in bioethanol production industry
microRNA-1 and microRNA-206 regulate skeletal muscle satellite cell proliferation and differentiation by repressing Pax7
Pax7 is a target of two miRNAs that are induced during muscle satellite cell differentiation and repressed in response to muscle injury
DNA linking number change induced by sequence-specific DNA-binding proteins
Sequence-specific DNA-binding proteins play a key role in many fundamental biological processes, such as transcription, DNA replication and recombination. Very often, these DNA-binding proteins introduce structural changes to the target DNA-binding sites including DNA bending, twisting or untwisting and wrapping, which in many cases induce a linking number change (ΔLk) to the DNA-binding site. Due to the lack of a feasible approach, ΔLk induced by sequence-specific DNA-binding proteins has not been fully explored. In this paper we successfully constructed a series of DNA plasmids that carry many tandem copies of a DNA-binding site for one sequence-specific DNA-binding protein, such as λ O, LacI, GalR, CRP and AraC. In this case, the protein-induced ΔLk was greatly amplified and can be measured experimentally. Indeed, not only were we able to simultaneously determine the protein-induced ΔLk and the DNA-binding constant for λ O and GalR, but also we demonstrated that the protein-induced ΔLk is an intrinsic property for these sequence-specific DNA-binding proteins. Our results also showed that protein-mediated DNA looping by AraC and LacI can induce a ΔLk to the plasmid DNA templates. Furthermore, we demonstrated that the protein-induced ΔLk does not correlate with the protein-induced DNA bending by the DNA-binding proteins
The histone methyltransferase Set7/9 promotes myoblast differentiation and myofibril assembly
Set7 associates with the MyoD transcription factor to enhance expression of genes required for muscle differentiation
Purification, crystallization and preliminary crystallographic analysis of recombinant Lac15 from a marine microbial metagenome
Enhanced resistance of Saccharomyces cerevisiae to vanillin by expression of lacA from Trametes sp. AH28-2
Saccharomyces cerevisiae is affected by the presence of certain phenolic compounds such as vanillin during fermentation of pretreated lignocellulosic hydrolysates. Since vanillin can be polymerized in the presence of laccase into compounds with lower toxicity, the laccase gene, lacA, from Trametes sp. AH28-2 was fused to the α-factor signal sequence and transferred into S. cerevisiae CEN.PK strains for secretory expression. Furthermore, the chaperone gene, KAR2, was overexpressed to promote the translocation of laccase. In the presence of 8mmol/L vanillin, a shorter lag phase was observed in the lacA gene expressing strains. The vanillin-specific conversion rate of the lacA-expressing strain BSJX0A2 was 0.069gg -1biomassh -1, while it was 0.065gg -1biomassh -1 in the reference strain.</p