2,010 research outputs found

    Aleth-NeRF: Low-light Condition View Synthesis with Concealing Fields

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    Common capture low-light scenes are challenging for most computer vision techniques, including Neural Radiance Fields (NeRF). Vanilla NeRF is viewer-centred that simplifies the rendering process only as light emission from 3D locations in the viewing direction, thus failing to model the low-illumination induced darkness. Inspired by emission theory of ancient Greek that visual perception is accomplished by rays casting from eyes, we make slight modifications on vanilla NeRF to train on multiple views of low-light scene, we can thus render out the well-lit scene in an unsupervised manner. We introduce a surrogate concept, Concealing Fields, that reduce the transport of light during the volume rendering stage. Specifically, our proposed method, Aleth-NeRF, directly learns from the dark image to understand volumetric object representation and concealing field under priors. By simply eliminating Concealing Fields, we can render a single or multi-view well-lit image(s) and gain superior performance over other 2D low light enhancement methods. Additionally, we collect the first paired LOw-light and normal-light Multi-view (LOM) datasets for future research.Comment: website page: https://cuiziteng.github.io/Aleth_NeRF_web

    An unprecedented binodal (4,6)-connected Co(II) MOF as dual-responsive luminescent sensor for detection of acetylacetone and Hg2+ ions

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    A new Co(II) organic framework, {[Co2(L)(hfpd)(H2O)]·1.75H2O}n (1) (H4hfpd = 4,4′-(hexafluoroisopropylidene)diphthalic acid, L = 4,4′-bis(imidazol-1-yl)-biphenyl) was hydrothermally synthesized and characterized. 1 possesses an unusual (4,6)-connected layered network architecture. Fluorescence titration results present that 1 is rarely dual-responsive probe to detect acetylacetone and Hg2+ ions by luminescence quenching.publishe

    Bayesian Nested Neural Networks for Uncertainty Calibration and Adaptive Compression

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    Nested networks or slimmable networks are neural networks whose architectures can be adjusted instantly during testing time, e.g., based on computational constraints. Recent studies have focused on a "nested dropout" layer, which is able to order the nodes of a layer by importance during training, thus generating a nested set of sub-networks that are optimal for different configurations of resources. However, the dropout rate is fixed as a hyper-parameter over different layers during the whole training process. Therefore, when nodes are removed, the performance decays in a human-specified trajectory rather than in a trajectory learned from data. Another drawback is the generated sub-networks are deterministic networks without well-calibrated uncertainty. To address these two problems, we develop a Bayesian approach to nested neural networks. We propose a variational ordering unit that draws samples for nested dropout at a low cost, from a proposed Downhill distribution, which provides useful gradients to the parameters of nested dropout. Based on this approach, we design a Bayesian nested neural network that learns the order knowledge of the node distributions. In experiments, we show that the proposed approach outperforms the nested network in terms of accuracy, calibration, and out-of-domain detection in classification tasks. It also outperforms the related approach on uncertainty-critical tasks in computer vision.Comment: 16 pages, 10 figure

    Increased expression of cyclooxygenase-2 in first-degree relatives of gastric cancer patients

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    Aim: To study the expression of cyclooxygenase-2 (COX-2) in human gastric cancer tissues and their paired adjacent mucosa, as well as mucosa from gastric antrum and corpus of the first-degree relatives of the recruited cancer patients. Methods: The expression of COX-2 mRNA in 38 patients with gastric cancer and their 29 first-degree relatives and 18 healthy controls was assessed by the real time RT-PCR. The expression of COX-2 protein was determined by Western blot. Results: A marked increase in COX-2 mRNA expression was found in 20 of 37 (54%) cancerous tissues compared to their respective paired normal mucosa (P<0.001). Interestingly, increased COX-2 mRNA expression was also found in mucosa of the corpus (6/29) and antrum (13/29) of their first-degree relatives. Increased COX-2 mRNA expression was more frequently observed in the antrum biopsies from cancer patients than in the antrum biopsies from healthy controls (P<0.05). In addition, 3 of 23 (13%) patients with atrophic mucosa and 6 of 35 (17%) patients with intestinal metaplasia showed increased COX-2 mRNA expression. Furthermore, COX-2 expression increased in H pylori-positive tissues, especially in antrum mucosa. Conclusion: Increased COX-2 expression is involved in gastric carcinogenesis, and may be necessary for maintenance of the malignant phenotype and contribute to Helicobacter pylori-associated malignant transformation. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio

    You Only Need 90K Parameters to Adapt Light: A Light Weight Transformer for Image Enhancement and Exposure Correction

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    Challenging illumination conditions (low-light, under-exposure and over-exposure) in the real world not only cast an unpleasant visual appearance but also taint the computer vision tasks. After camera captures the raw-RGB data, it renders standard sRGB images with image signal processor (ISP). By decomposing ISP pipeline into local and global image components, we propose a lightweight fast Illumination Adaptive Transformer (IAT) to restore the normal lit sRGB image from either low-light or under/over-exposure conditions. Specifically, IAT uses attention queries to represent and adjust the ISP-related parameters such as colour correction, gamma correction. With only ~90k parameters and ~0.004s processing speed, our IAT consistently achieves superior performance over SOTA on the current benchmark low-light enhancement and exposure correction datasets. Competitive experimental performance also demonstrates that our IAT significantly enhances object detection and semantic segmentation tasks under various light conditions. Training code and pretrained model is available at https://github.com/cuiziteng/Illumination-Adaptive-Transformer.Comment: 23 page

    Capillary Hemangioma of the Middle Ear and External Auditory Canal: a Case Report

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    AbstractWe report a case of capillary hemangiomsa that involved the entire middle ear space, external auditory canal(EAC) and tympanic antrum. Symptoms in the case included ear fullness, hearing loss, otalgia and otorrhea. The case was misdiagnosed as recurrent chronic otitis media with granulation preoperatively. A diagnosis of capillary hemangioma was established by postoperative histological examination. The management of capillary hemangioma of the middle ear and external auditory canal is discussed, with a review of the literature. Because of its variable and sometimes misleading clinical presentation, hemangioma can initially be misdiagnosed as other lesions. Therefore, a high index of suspicion is necessary for early and accurate diagnosis

    Effect of estradiol on proliferation and differentiation of side population stem/progenitor cells from murine endometrium

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    <p>Abstract</p> <p>Background</p> <p>In our previous study, endometrium side population cells (SP cells) were isolated from postpartum murine uterus, and characterized by a heterogeneous population of stem/progenitor cells. In this study, we investigated the effect of estrogen on the proliferation and differentiation of SP cells.</p> <p>Methods</p> <p>SP and non-SP cells of postpartum murine endometrium were isolated by DNA dye Hoechst 33342. The expression of estrogen receptor 1 (ESR1) was measured by reverse transcription polymerase chain reaction (RT-PCR), Real-time PCR, Western blot, immunofluorescence and immunohistochemistry. The proliferation and differentiation of SP cells treated with different concentrations [10(-8) M-10(-6) M] of estradiol (E2) and E2+ ICI182780 (Faslodex, inhibitor of ESR1) were measured by 3-(4, 5-dimethylthiazoly1-2)-2,5-diphenyltetrazolium bromide(MTT) and clonogenic assays.</p> <p>Results</p> <p>(1) SP cells expressed ESR1 at a higher level than non-SP cells. (2) The level of E2 in the serum and the expression of ESR1 in the uterus of postpartum murine changed in the same manner with the ratio of SP cells to total uterus cells at a different postpartum time point. ESR1, as ABCG2 is also predominantly located in the stroma and the glandular epithelium of the uterus. (3) 10(-6) M E2 notably promoted the proliferation of SP cells after treatment for 24 h. This effect could be inhibited by ICI182780. E2 at the concentration of 10(-7) M or 10(-8) M was sent to impair the large cloning efficiency (CE) of SP cells.</p> <p>Conclusions</p> <p>The effect of estrogen on the proliferation and differentiation of endometrium SP cells via ESR1 was observed and it was in a concentration dependent fashion. Clearly, more work is needed to understand the <it>in vivo </it>effect of E2 at the physiological concentration on the differentiation of SP cells.</p

    Integration of the metabolome and transcriptome reveals the metabolites and genes related to nutritional and medicinal value in Coriandrum sativum

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    Coriandrum sativum (Coriander) or Chinese parsley is a culinary herb with multiple medicinal effects, which is widely used in cooking and traditional medicine. It is enriched with essential oils and anti-oxidant compounds with unknown significance. To explore the untapped reservoir of Coriander, we studied the transcriptome and metabolic profiles from three developmental stages. Here, we identified 10 tyrosine metabolic pathway-related genes (TMPRGs), six porphyrins and chlorophyll metabolic pathway-related genes (PCMPRGs), and five Vitamin E metabolic pathway-related genes (VEMPRGs). These genes were associated with the early development of Coriander. Our analysis suggests that these pathways are involved in the production of critical phenolic metabolites. Furthermore, we constructed the interaction network between these pathway-related genes and transcription factors (TFs), which supported the regulatory pathways for phenolic metabolites. Interestingly, we identified several nutritional or medicinally relevant metabolites, including 59 phenols, two polyamines, 12 alkaloids, and one terpenoid. The higher concentrations of metabolites were from caffeic acid, agmatine, and its derivatives. We found higher levels of caffeic acid and agmatine at 30 days compared to 60 or 90 days. This study provides evidence to stimulate further investigation of the role of these metabolites in medicinal and nutritional research
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