230 research outputs found

    Cross-attention learning enables real-time nonuniform rotational distortion correction in OCT

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    Nonuniform rotational distortion (NURD) correction is vital for endoscopic optical coherence tomography (OCT) imaging and its functional extensions, such as angiography and elastography. Current NURD correction methods require time-consuming feature tracking or cross-correlation calculations and thus sacrifice temporal resolution. Here we propose a cross-attention learning method for the NURD correction in OCT. Our method is inspired by the recent success of the self-attention mechanism in natural language processing and computer vision. By leveraging its ability to model long-range dependencies, we can directly obtain the correlation between OCT A-lines at any distance, thus accelerating the NURD correction. We develop an end-to-end stacked cross-attention network and design three types of optimization constraints. We compare our method with two traditional feature-based methods and a CNN-based method, on two publicly-available endoscopic OCT datasets and a private dataset collected on our home-built endoscopic OCT system. Our method achieved a āˆ¼3Ɨ\sim3\times speedup to real time (26Ā±326\pm 3 fps), and superior correction performance

    Effects of Enzymatic Hydrolysis on the Allergenicity of Whey Protein Concentrates

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    Cowā€™s milk whey consists of many protein components and some of them are antigens to human and known to modulate immune responses. Enzymatic hydrolysis is a useful method to modify proteins with allergenicity. The objective of this study was to identify whether the in vitro enzymatic hydrolysis could reduce the allergenicity of whey protein concentrates (WPC). InĀ  this study, WPC were hydrolyzed by trypsin and twenty-four BALB/c mice were divided into three groups and fed with WPC formula and WPC hydrolysates formula, while the control mice received milk-free diet. The results revealed that there was no significant difference between the body weights among all groups. WPC-fed mice produced an elevated spleen lymphocyte proliferation level than WPC hydrolysates-fed mice and also produced higher levels of WPC-specific IgE in intestinal tract and serum in comparison to WPC hydrolysates-fed mice and control group. Significant up-regulation of plasma histamine levels were also observed and showed the same trend with IgE. The secretions of IL-4 and IL-5 were significantly enhanced by WPC. WPC significantly suppressedĀ  theĀ  secretion ofĀ  IFN-Ī³Ā  while hydrolysates ofĀ  WPC significantly increased the secretion of IFN-Ī³ compared to control group. These results suggest that hydrolysis may play a role to reduce the allergenicity of WPC

    Transcriptome and metabolome profiling of the medicinal plant Veratrum mengtzeanum reveal key components of the alkaloid biosynthesis

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    Veratrum mengtzeanum is the main ingredient for Chinese folk medicine known as ā€œPimacaoā€ due to its unique alkaloids. A diverse class of plant-specific metabolites having key pharmacological activities. There are limited studies on alkaloid synthesis and its metabolic pathways in plants. To elucidate the alkaloid pathway and identify novel biosynthetic enzymes and compounds in V. mengtzeanum, transcriptome and metabolome profiling has been conducted in leaves and roots. The transcriptome of V. mengtzeanum leaves and roots yielded 190,161 unigenes, of which 33,942 genes expressed differentially (DEGs) in both tissues. Three enriched regulatory pathways (isoquinoline alkaloid biosynthesis, indole alkaloid biosynthesis and tropane, piperidine and pyridine alkaloid biosynthesis) and a considerable number of genes such as AED3-like, A4U43, 21Ā kDa protein-like, 3-O-glycotransferase 2-like, AtDIR19, MST4, CASP-like protein 1D1 were discovered in association with the biosynthesis of alkaloids in leaves and roots. Some transcription factor families, i.e., AP2/ERF, GRAS, NAC, bHLH, MYB-related, C3H, FARI, WRKY, HB-HD-ZIP, C2H2, and bZIP were also found to have a prominent role in regulating the synthesis of alkaloids and steroidal alkaloids in the leaves and roots of V. mengtzeanum. The metabolome analysis revealed 74 significantly accumulated metabolites, with 55 differentially accumulated in leaves compared to root tissues. Out of 74 metabolites, 18 alkaloids were highly accumulated in the roots. A novel alkaloid compound viz; 3-Vanilloylygadenine was discovered in root samples. Conjoint analysis of transcriptome and metabolome studies has also highlighted potential genes involved in regulation and transport of alkaloid compounds. Here, we have presented a comprehensive metabolic and transcriptome profiling of V. mengtzeanum tissues. In earlier reports, only the roots were reported as a rich source of alkaloid biosynthesis, but the current findings revealed both leaves and roots as significant manufacturing factories for alkaloid biosynthesis

    Bear-proof fences reduce livestock losses in the Tibetan Autonomous Region, China

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    Tibetan brown bears Ursus arctos pruinosus in the Tibetan Plateau attack and kill livestock and ransack homes for food, causing significant economic costs for local herders. Although a government fund compensates herders for livestock lost to bear attacks in the Tibetan Autonomous Region (China), compensation may not reflect the real cost of losing livestock and payments can be delayed. We investigate whether bear-proof fences are a cost-effective method for reducing bear attacks and livestock losses. In January 2009, 14 bear-proof fences were constructed from wire mesh and steel posts around households which had previously experienced substantial losses to bear attacks in the Nagqu Prefecture of the Tibetan Autonomous Region. These households lost 162 animals to bears in the year before fence construction, whereas just three animals were lost in the year after fence construction. Fences were still standing 4.8 years after completion and any small damage has been repaired by households. For households that suffer substantial losses to bear attacks, bear-proof fences appear to be an effective and cost-saving intervention to reduce human-bear conflict

    Bear-proof fences reduce livestock losses in the Tibetan Autonomous Region, China

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    Tibetan brown bears Ursus arctos pruinosus in the Tibetan Plateau attack and kill livestock and ransack homes for food, causing significant economic costs for local herders. Although a government fund compensates herders for livestock lost to bear attacks in the Tibetan Autonomous Region (China), compensation may not reflect the real cost of losing livestock and payments can be delayed. We investigate whether bear-proof fences are a cost-effective method for reducing bear attacks and livestock losses. In January 2009, 14 bear-proof fences were constructed from wire mesh and steel posts around households which had previously experienced substantial losses to bear attacks in the Nagqu Prefecture of the Tibetan Autonomous Region. These households lost 162 animals to bears in the year before fence construction, whereas just three animals were lost in the year after fence construction. Fences were still standing 4.8 years after completion and any small damage has been repaired by households. For households that suffer substantial losses to bear attacks, bear-proof fences appear to be an effective and cost-saving intervention to reduce human-bear conflict

    Leukotriene B4 receptor knockdown affects PI3K/AKT/mTOR signaling and apoptotic responses in colorectal cancer

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    Colorectal cancer (CRC) presents a landscape of intricate molecular dynamics. In this study, we focused on the role of the leukotriene B4 receptor (LTB4R) in CRC, exploring its significance in the disease's progression and potential therapeutic approaches. Using bioinformatics analysis of the GSE164191 and the Cancer Genome Atlas-colorectal adenocarcinoma (TCGA-COAD) datasets, we identified LTB4R as a hub gene influencing CRC prognosis. Subsequently, we examined the relationship between LTB4R expression, apoptosis, and the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway through cellular and mice experiments. Our findings revealed that LTB4R is highly expressed in CRC samples and is pivotal for determining prognosis. In vitro experiments demonstrated that silencing LTB4R significantly impeded CRC cell viability, migration, invasion, and colony formation. Correspondingly, in vivo tests indicated that LTB4R knockdown led to markedly slower tumor growth in mice models. Further in-depth investigation revealed that LTB4R knockdown significantly amplified the apoptosis in CRC cells and upregulated the expression of apoptosis-related proteins, such as caspase-3 and caspase-9, while diminishing p53 expression. Interestingly, silencing LTB4R also resulted in a significant downregulation of the PI3K/AKT/mTOR signaling pathway. Moreover, pretreatment with the PI3K activator 740Y-P only partially attenuated the effects of LTB4R knockdown on CRC cell behavior, emphasizing LTB4R's dominant influence in CRC cell dynamics and signaling pathways. LTB4R stands out as a critical factor in CRC progression, profoundly affecting cellular behavior, apoptotic responses, and the PI3K/AKT/mTOR signaling pathway. These findings not only shed light on LTB4R's role in CRC but also establish it as a potential diagnostic biomarker and a promising target for therapeutic intervention

    Enhancing Nanoparticle-Based Visible Detection by Controlling the Extent of Aggregation

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    Visible indication based on the aggregation of colloidal nanoparticles (NPs) is highly advantageous for rapid on-site detection of biological entities, which even untrained persons can perform without specialized instrumentation. However, since the extent of aggregation should exceed a certain minimum threshold to produce visible change, further applications of this conventional method have been hampered by insufficient sensitivity or certain limiting characteristics of the target. Here we report a signal amplification strategy to enhance visible detection by introducing switchable linkers (SLs), which are designed to lose their function to bridge NPs in the presence of target and control the extent of aggregation. By precisely designing the system, considering the quantitative relationship between the functionalized NPs and SLs, highly sensitive and quantitative visible detection is possible. We confirmed the ultrahigh sensitivity of this method by detecting the presence of 20 fM of streptavidin and fewer than 100 CFU/mL of Escherichia coli

    Evaluation of the hepatotoxicity of Psoralea corylifolia L. based on a zebrafish model

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    Objective:Psoralea corylifolia L. (FP) has received increasing attention due to its potential hepatotoxicity.Methods: In this study, zebrafish were treated with different concentrations of an aqueous extract of FP (AEFP; 40, 50, or 60Ā Ī¼g/mL), and the hepatotoxic effects of tonicity were determined by the mortality rate, liver morphology, fluorescence area and intensity of the liver, biochemical indices, and pathological tissue staining. The mRNA expression of target genes in the bile acid metabolic signaling pathway and lipid metabolic pathway was detected by qPCR, and the mechanism of toxicity was initially investigated. AEFP (50Ā Ī¼g/mL) was administered in combination with FXR or a peroxisome proliferator-activated receptor Ī± (PPARĪ±) agonist/inhibitor to further define the target of toxicity.Results: Experiments on toxic effects showed that, compared with no treatment, AEFP administration resulted in liver atrophy, a smaller fluorescence area in the liver, and a lower fluorescence intensity (p < 0.05); alanine transaminase (ALT), aspartate transaminase (AST), and Ī³-GT levels were significantly elevated in zebrafish (p < 0.01), and TBA, TBIL, total cholesterol (TC), TG, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels were elevated to different degrees (p < 0.05); and increased lipid droplets in the liver appeared as fatty deposits. Molecular biological validation revealed that AEFP inhibited the expression of the FXR gene, causing an increase in the expression of the downstream genes SHP, CYP7A1, CYP8B1, BSEP, MRP2, NTCP, peroxisome proliferator-activated receptor Ī³ (PPARĪ³), ME-1, SCD-1, lipoprotein lipase (LPL), CPT-1, and CPT-2 and a decrease in the expression of PPARĪ± (p < 0.05).Conclusion: This study demonstrated that tonic acid extracts are hepatotoxic to zebrafish through the inhibition of FXR and PPARĪ± expression, thereby causing bile acid and lipid metabolism disorders
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