1,978 research outputs found

    DiffRef3D: A Diffusion-based Proposal Refinement Framework for 3D Object Detection

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    Denoising diffusion models show remarkable performances in generative tasks, and their potential applications in perception tasks are gaining interest. In this paper, we introduce a novel framework named DiffRef3D which adopts the diffusion process on 3D object detection with point clouds for the first time. Specifically, we formulate the proposal refinement stage of two-stage 3D object detectors as a conditional diffusion process. During training, DiffRef3D gradually adds noise to the residuals between proposals and target objects, then applies the noisy residuals to proposals to generate hypotheses. The refinement module utilizes these hypotheses to denoise the noisy residuals and generate accurate box predictions. In the inference phase, DiffRef3D generates initial hypotheses by sampling noise from a Gaussian distribution as residuals and refines the hypotheses through iterative steps. DiffRef3D is a versatile proposal refinement framework that consistently improves the performance of existing 3D object detection models. We demonstrate the significance of DiffRef3D through extensive experiments on the KITTI benchmark. Code will be available

    Fundamental Elements for Successful Performance of CT Colonography (Virtual Colonoscopy)

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    There are many factors affecting the successful performance of CT colonography (CTC). Adequate colonic cleansing and distention, the optimal CT technique and interpretation with using the newest CTC software by a trained reader will help ensure high accuracy for lesion detection. Fecal and fluid tagging may improve the diagnostic accuracy and allow for reduced bowel preparation. Automated carbon dioxide insufflation is more efficient and may be safer for colonic distention as compared to manual room air insufflation. CT scanning should use thin collimation of ≤3 mm with a reconstruction interval of ≤1.5 mm and a low radiation dose. There is not any one correct method for the interpretation of CTC; therefore, readers should be well-versed with both the primary 3D and 2D reviews. Polyps detected at CTC should be measured accurately and reported following the "polyp size-based" patient management system. The time-intensive nature of CTC and the limited resources for training radiologists appear to be the major barriers for implementing CTC in Korea

    Bucillamine prevents cisplatin-induced ototoxicity through induction of glutathione and antioxidant genes.

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    Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH

    Bezoar-induced Small Bowel Obstruction

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    Purpose: The aim of this study was to observe the clinical features of a bezoar-induced small bowel obstruction and to in-vestigate the role of abdominal computed tomography (CT) in establishing the diagnosis. Methods: We retrospectively reviewed 20 cases of bezoar-induced small bowel obstruction in our hospital from 1996 to 2010. Results: Thirteen patients (65%) had a history of abdominal surgery. Nine patients (45%) were diagnosed with a bezoar before surgery, seven patients were diagnosed by using abdominal CT, and two patients were diagnosed with a small bowel series. Abdominal CT was performed in 15 patients, and the diagnostic accuracy was 47 % (7/15). Surgery revealed ten bezoars in the jejunum and 11 in the ileum. Two patients had bezoars found concurrently in the stomach. Spontaneous removal took place in two patients. An enterotomy and bezoar extraction was performed in 15 patients. Fragmentation and milking, a small bowel resection, and a Meckel’s diverticulectomy were performed in one patient each. Early operative treatment was possible (P = 0.036) once the bezoar had been diagnosed by using abdominal CT. There tended to be fewer postoperative complications in patients who were diagnosed with a bezoar by using abdominal CT, but the result was not statistically significant (P = 0.712). Conclusion: A preoperative diagnosis of bezoar-induced small bowel obstruction by using clinical features was difficult. Increased use of abdominal CT led to a more accurate diagnosis and to earlier surgery for bezoar-induced small bowel obstructions, thereby reducing the rate of complications
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