457 research outputs found

    Control of Cochlodinium polykrikoides, a Red tide Dinoflagellate Using Chemical Disinfectants

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    Department of Urban and Environmental Engineering(Environmental Science And Engineering)The harmful algal blooms (HABs) often involve serious economic loss of marine resources and contribute to pollution of coastal areas by causing the mass mortality of natural and aquaculture fish and shellfish. While spraying activated clay is a common practice to mitigate damage from red tide, it is not strong enough to completely control the red tide bloom. The use of chemical oxidants, frequently employed for disinfection in water treatment processes, is a potential method to reduce the risk from red tide for inland fish farms. In this study, chemical disinfectants were investigated as alternative technologies to control red tide in terms of the removal efficiency of C. polykrikoides, formation of byproduct, and toxicity to fish. The first part of this study investigated the removal of C. polykrikoides by various oxidants including ozone (O3), permanganate (MnO4-), chlorine (Cl2) and hydrogen peroxide (H2O2) according to cell density and oxidant dose. O3 showed a much higher efficiency for the C. polykrikoides removal than the other oxidants under identical experimental conditions. Disinfectants effectively inactivate the C. polykrikoides in the order of O3 > MnO4- > Cl2 > H2O2. TRO produced from O3 and Cl2 mostly converted into HOBr due to the presence of bromide ion (Br-) in seawater. The seawater in the presence of C. polykrikoides decayed faster than in the absence of C. polykrikoides, indicating that TRO decay and HOBr production can be affected by the characteristics of water quality. Ozonation results in a much higher formation of bromate (BrO3-) than treatments with Cl2, MnO4-, and H2O2. The acute toxicity of MnO4-, Cl2, and H2O2 to juvenile red sea bream was reached at 72-h LC50 values of 0.39, 1.32, and 102.61 ppm, respectively. Secondly, the aim of this study to evaluate the removal efficiency of C. polykrikoides by O3 according to various factors affecting the efficiency such as cell density, oxidant dose, humic acid concentration, carbonate concentration, pH, and temperature. The removal of C. polykrikoides by O3 was rapid, and appeared to be caused by initial ozonation, and then slow reaction, in which Br- was oxidized to HOBr. Low pH and temperature increased the removal efficiency. Thus, the C. polykrikoides removal efficiency with a low pH, and low temperature, and a high O3 dose increased as the in exposure to O3 increased. The BrO3- concentration of less than 10.0 ppb (WHO, 2011) can only be maintained at the O3 dose of less than 1.0 ppm.ope

    Source-free Subject Adaptation for EEG-based Visual Recognition

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    This paper focuses on subject adaptation for EEG-based visual recognition. It aims at building a visual stimuli recognition system customized for the target subject whose EEG samples are limited, by transferring knowledge from abundant data of source subjects. Existing approaches consider the scenario that samples of source subjects are accessible during training. However, it is often infeasible and problematic to access personal biological data like EEG signals due to privacy issues. In this paper, we introduce a novel and practical problem setup, namely source-free subject adaptation, where the source subject data are unavailable and only the pre-trained model parameters are provided for subject adaptation. To tackle this challenging problem, we propose classifier-based data generation to simulate EEG samples from source subjects using classifier responses. Using the generated samples and target subject data, we perform subject-independent feature learning to exploit the common knowledge shared across different subjects. Notably, our framework is generalizable and can adopt any subject-independent learning method. In the experiments on the EEG-ImageNet40 benchmark, our model brings consistent improvements regardless of the choice of subject-independent learning. Also, our method shows promising performance, recording top-1 test accuracy of 74.6% under the 5-shot setting even without relying on source data. Our code can be found at https://github.com/DeepBCI/Deep-BCI/tree/master/1_Intelligent_BCI/Source_Free_Subject_Adaptation_for_EEG.Comment: Accepted by the 11th IEEE International Winter Conference on Brain-Computer Interface (BCI 2023). Code is available at https://github.com/DeepBCI/Deep-BC

    BallGAN: 3D-aware Image Synthesis with a Spherical Background

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    3D-aware GANs aim to synthesize realistic 3D scenes such that they can be rendered in arbitrary perspectives to produce images. Although previous methods produce realistic images, they suffer from unstable training or degenerate solutions where the 3D geometry is unnatural. We hypothesize that the 3D geometry is underdetermined due to the insufficient constraint, i.e., being classified as real image to the discriminator is not enough. To solve this problem, we propose to approximate the background as a spherical surface and represent a scene as a union of the foreground placed in the sphere and the thin spherical background. It reduces the degree of freedom in the background field. Accordingly, we modify the volume rendering equation and incorporate dedicated constraints to design a novel 3D-aware GAN framework named BallGAN. BallGAN has multiple advantages as follows. 1) It produces more reasonable 3D geometry; the images of a scene across different viewpoints have better photometric consistency and fidelity than the state-of-the-art methods. 2) The training becomes much more stable. 3) The foreground can be separately rendered on top of different arbitrary backgrounds.Comment: Project Page: https://minjung-s.github.io/ballga

    Dentists attitudes toward patient-centered care and its predictors: a cross-sectional study in South Korea

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    Background Patient-centered care (PCC) has been one of medical practices most frequently discussed principles. However, attitudes toward PCC among dentists remain underexplored. This study focuses on examining dentists patient-centered attitudes and investigating their predictors. Methods The Patient–Practitioner Orientation Scale which consists of Sharing and Caring subscales was used to assess patient-centered attitudes. The statistical analysis included 217 dentists from South Korea. Hierarchical linear regression analysis was performed to examine the predictors such as sociodemographic aspects, academic factors, work-related factors, and empathy. Results A patient-centered attitude of Caring subscale (M = 4.29, SD = 0.56) emerged, but the provider-centered attitude was higher in Sharing subscale (M = 3.40, SD = 0.48). Work year, academic track, and empathy were associated significantly with an overall caring aspect of patient-centered attitude, while the gender effect remained insignificant. Empathy had a critical and significant impact on the patient-centered attitude. Conclusions Efforts to enhance patient-centeredness in Sharing are needed; post-graduate education and transition to a more patient-centered health system are recommended. Moreover, empathy still matters as it was found to be a significant predictor of patient-centered attitudes. The findings of this study support the need for efforts to enhance patient-centered attitudes among dentists, which will help generate discussion on improving the curriculum of post-graduate education and health system reform

    Dysbiotic microbiome variation in colorectal cancer patients is linked to lifestyles and metabolic diseases

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    Abstract Background Differences in the composition and diversity of the gut microbial communities among individuals are influenced by environmental factors. However, there is limited research on factors affecting microbiome variation in colorectal cancer patients, who display lower inter-individual variations than that of healthy individuals. In this study, we examined the association between modifiable factors and the microbiome variation in colorectal cancer patients. Methods A total of 331 colorectal cancer patients who underwent resection surgery at the Department of Surgery, Seoul National University Hospital between October 2017 and August 2019 were included. Fecal samples from colorectal cancer patients were collected prior to the surgery. Variations in the gut microbiome among patients with different lifestyles and metabolic diseases were examined through the network analysis of inter-connected microbial abundance, the assessment of the Anna Karenina principle effect for microbial stochasticity, and the identification of the enriched bacteria using linear discrimination analysis effect size. Associations of dietary diversity with microbiome variation were investigated using the Procrustes analysis. Results We found stronger network connectivity of microbial communities in non-smokers, non-drinkers, obese individuals, hypertensive subjects, and individuals without diabetes than in their counterparts. The Anna Karenina principle effect was found for history of smoking, alcohol consumption, and diabetes (with significantly greater intra-sample similarity index), whereas obesity and hypertension showed the anti-Anna Karenina principle effect (with significantly lower intra-sample similarity index). We found certain bacterial taxa to be significantly enriched in patients of different categories of lifestyles and metabolic diseases using linear discrimination analysis. Diversity of food and nutrient intake did not shape the microbial diversity between individuals (pProcrustes>0.05). Conclusions Our findings suggested an immune dysregulation and a reduced ability of the host and its microbiome in regulating the community composition. History of smoking, alcohol consumption, and diabetes were shown to affect partial individuals in shifting new microbial communities, whereas obesity and history of hypertension appeared to affect majority of individuals and shifted to drastic reductions in microbial compositions. Understanding the contribution of modifiable factors to microbial stochasticity may provide insights into how the microbiome regulates effects of these factors on the health outcomes of colorectal cancer patients.This study was supported by grants from Seoul National University Hospital (No. 0420190530) and the National Research Foundation of Korea (NRF) grant funded by the Korea goverment (MSIT) (No. 2022R1A2C1004608). The funding bodies have no role in study design, collection, analysis, interpretation of data,or writing the manuscript. The authors declare no conficts of interest. Authors Minjung Kim and Aesun Shin had full access to all the data in the study and took responsibility for the integrity of the data and the accuracy of the data analysis

    The complete chloroplast genome sequence of Abies nephrolepis (Pinaceae: Abietoideae)

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    AbstractThe plant chloroplast (cp) genome has maintained a relatively conserved structure and gene content throughout evolution. Cp genome sequences have been used widely for resolving evolutionary and phylogenetic issues at various taxonomic levels of plants. Here, we report the complete cp genome of Abies nephrolepis. The A. nephrolepis cp genome is 121,336 base pairs (bp) in length including a pair of short inverted repeat regions (IRa and IRb) of 139 bp each separated by a small single copy (SSC) region of 54,323 bp (SSC) and a large single copy region of 66,735 bp (LSC). It contains 114 genes, 68 of which are protein coding genes, 35 tRNA and four rRNA genes, six open reading frames, and one pseudogene. Seventeen repeat units and 64 simple sequence repeats (SSR) have been detected in A. nephrolepis cp genome. Large IR sequences locate in 42-kb inversion points (1186 bp). The A. nephrolepis cp genome is identical to Abies koreana’s which is closely related to taxa. Pairwise comparison between two cp genomes revealed 140 polymorphic sites in each. Complete cp genome sequence of A. nephrolepis has a significant potential to provide information on the evolutionary pattern of Abietoideae and valuable data for development of DNA markers for easy identification and classification

    Can clinical scoring systems improve the diagnostic accuracy in patients with suspected adult appendicitis and equivocal preoperative computed tomography findings?

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    Objective Adult appendicitis (AA) with equivocal computed tomography (CT) findings remains a diagnostic challenge for physicians. Herein we evaluated the diagnostic performance of several clinical scoring systems in adult patients with suspected appendicitis and equivocal CT findings. Methods We retrospectively evaluated 189 adult patients with equivocal CT findings. Alvarado, Eskelinen, appendicitis inflammatory response, Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA), and adult appendicitis score (AAS) scores were evaluated, receiver operating characteristic analysis was conducted, and the optimal, low, and high cut-off values were determined for patient classification into three groups: low, intermediate, or high. Results In total, 61 patients were included in the appendicitis group and 128 in the non-appendicitis group. There were no significant differences between the area under the curve of the clinical scoring systems in the final diagnosis of AA for equivocal appendicitis on CT (Alvarado, 0.698; Eskelinen, 0.710; appendicitis inflammatory response, 0.668; RIPASA, 0.653; AAS, 0.726). A RIPASA score greater than 7.5 had a high positive predictive value (90.9) and an AAS score less than or equal to 5 had a high negative predictive value (91.7) in the diagnosis of AA. Conclusion The accuracy of clinical scoring systems in the diagnosis of AA with equivocal CT findings was moderate. Therefore, a high RIPASA score may assist in the diagnosis of AA in patients with equivocal CT findings, and a low AAS score may be used as a criterion for patient discharge. Most patients presented with intermediate scores. The patients with equivocal CT findings may be considered as a third diagnostic category of AA

    Genomic profile of metastatic breast cancer patient-derived xenografts established using percutaneous biopsy.

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    BACKGROUND: Metastatic breast cancer (mBC) is a complex and life-threatening disease and although it is difficult to cure, patients can benefit from sequential anticancer treatment, including endocrine therapy, targeted therapy and cytotoxic chemotherapy. The patient-derived xenograft (PDX) model is suggested as a practical tool to predict the clinical outcome of this disease as well as to screen novel drugs. This study aimed to establish PDX models in Korean patients and analyze their genomic profiles and utility for translational research. METHODS: Percutaneous core needle biopsy or punch biopsy samples were used for xenotransplantation. Whole exome sequencing and transcriptome analysis were performed to assess the genomic and RNA expression profiles, respectively. Copy number variation and mutational burden were analyzed and compared with other metastatic breast cancer genomic results. Mutational signatures were also analyzed. The antitumor effect of an ATR inhibitor was tested in the relevant PDX model. RESULTS: Of the 151 cases studied, 40 (26%) PDX models were established. Notably, the take rate of all subtypes, including the hormone receptor-positive (HR +) subtype, exceeded 20%. The PDX model had genomic fidelity and copy number variation that represented the pattern of its donor sample. TP53, PIK3CA, ESR1, and GATA3 mutations were frequently found in our samples, with TP53 being the most frequently mutated, and the somatic mutations in these genes strengthened their frequency in the PDX model. The ESR1 mutation, CCND1 amplification, and the APOBEC signature were significant features in our HR + HER2- PDX model. Fulvestrant in combination with palbociclib showed a partial response to the relevant patient\u27s tumor harboring the ESR1 mutation, and CCND1 amplification was found in the PDX model. AZD6738, an ATR inhibitor, delayed tumor growth in a relevant PDX model. CONCLUSIONS: Our PDX model was established using core needle biopsy samples from primary and metastatic tissues. Genomic profiles of the samples reflected their original tissue characteristics and could be used for the interpretation of clinical outcomes

    Cryptotanshinone chemosensitivity potentiation by TW-37 in human oral cancer cell lines by targeting STAT3–Mcl-1 signaling

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    Abstract Background Despite being one of the leading cancer types in the world, the diagnosis of oral cancer and its suitable therapeutic options remain limited. This study aims to investigate the single and chemosensitizing effects of TW-37, a BH3 mimetic in oral cancer, on human oral cancer cell lines. Methods We assessed the single and chemosensitizing effects of TW-37 in vitro using trypan blue exclusion assay, Western blotting, DAPI staining, Annexin V–FITC/PI double staining, and quantitative real-time PCR. Mcl-1 overexpression models were established by transforming vector and transient transfection was performed to test for apoptosis Results TW-37 enhanced the cytotoxicity of human oral cancer cell lines by inducing caspase-dependent apoptosis, which correlates with the reduction of the myeloid cell leukemia-1 (Mcl-1) expression via transcriptional and post-translational regulation. The ectopic expression of Mcl-1 partially attenuated the apoptosis-inducing capacity of TW-37 in human oral cancer cell lines. Besides, TW-37 decreased the phosphorylation of signal transducer and activator of transcription 3 (STAT3) at Tyr705 and nuclear translocation in human oral cancer cell lines at the early time points. Furthermore, TW-37 potentiated chemosusceptibility of cryptotanshinone in human oral cancer cell lines by suppressing STAT3–Mcl-1 signaling compared with either TW-37 or cryptotanshinone alone, resulting in potent apoptosis. Conclusions This study not only unravels the single and chemosensitizing effects of TW-37 for treatment of human oral cancer but also highlights the likelihood of TW-37 as a good therapeutic strategy to enhance the prognosis of patients with oral cancer in the future
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