3D microscopic reconstruction of pearls using combined optical microscopy and photogrammetry

In this study, we introduce an affordable and accessible method that combines optical microscopy and photogrammetry to reconstruct 3D models of Tahitian pearls. We present a novel device designed for acquiring microscopic images around a sphere using translational displacement stages and outline our method for reconstructing these images. We successfully created 3D models of two individual pearl rings, each representing 6.3% of the pearl’s surface. Additionally, we generated a combined model representing 10.3% of the pearl’s surface. This showcases the potential for reconstructing entire pearls with appropriate instrumentation. We emphasize that our approach extends beyond pearls and spherical objects and can be adapted for various object types using appropriate acquisition devices. We provide a proof of concept demonstrating the feasibility of 3D photogrammetry using optical microscopy. Consequently, our method offers a practical and cost-effective alternative for generating 3D models at a microscopic scale, particularly when detailed internal structure information is unnecessary

Pearl shape classification using deep convolutional neural networks from Tahitian pearl rotation in Pinctada margaritifera

Abstract Tahitian pearls, artificially cultivated from the black-lipped pearl oyster Pinctada margaritifera, are renowned for their unique color and large size, making the pearl industry vital for the French Polynesian economy. Understanding the mechanisms of pearl formation is essential for enabling quality and sustainable production. In this paper, we explore the process of pearl formation by studying pearl rotation. Here we show, using a deep convolutional neural network, a direct link between the rotation of the pearl during its formation in the oyster and its final shape. We propose a new method for non-invasive pearl monitoring and a model for predicting the final shape of the pearl from rotation data with 81.9% accuracy. These novel resources provide a fresh perspective to study and enhance our comprehension of the overall mechanism of pearl formation, with potential long-term applications for improving pearl production and quality control in the industry

TACE and conformal radiotherapy vs. TACE alone for hepatocellular carcinoma: A randomised controlled trial

International audienceBackground & aims: Transcatheter arterial chemoembolisation (TACE) is recommended for patients with hepatocellular carcinoma devoid of macrovascular invasion or extrahepatic spread but not eligible for curative therapies. We compared the efficacy and safety of the combination of a single TACE and external conformal radiotherapy (CRT) vs. classical TACE.Methods: TACERTE was an open-labelled, randomised controlled trial with a 1:1 allocation rate to two or three TACE (arm A) or one TACE + CRT (arm B). Participants had a mean age of 70 years, and 86% were male. The aetiology was alcohol in 85%. The primary endpoint was liver progression-free survival (PFS) in the intention-to-treat population. The typical CRT schedule was 54 Gy in 18 sessions of 3 Gy.Results: Of the 120 participants randomised, 64 were in arm A and 56 in arm B; 100 participants underwent the planned schedule and defined the 'per-protocol' group. In intention-to-treat participants, the liver PFS at 12 and 18 months were 59% and 19% in arm A and 61% and 36% in arm B (hazard ratio [HR] 0.69; 95% CI 0.40-1.18; p = 0.17), respectively. In the per-protocol population, treated liver PFS tended to be better in arm B (HR 0.61; 95% CI 0.34-1.06; p = 0.081) than in arm A. Liver-related grade III-IV adverse events were more frequent in arm B than in arm A. Median overall survival reached 30 months (95% CI 23-35) in arm A and 22 months (95% CI 15.7-26.2) in arm B.Conclusions: Although TACE + CRT tended to improve local control, this first Western randomised controlled trial showed that the combined strategy failed to increase PFS or overall survival and led more frequently to liver-related adverse effects.Impact and implications: Hepatocellular carcinoma is frequently treated by arterial embolisation of the tumour and more recently by external radiotherapy. We tried to determine whether combination of the two treatments (irradiation after embolisation) might produce interesting results. Our results in this prospective randomised study were not able to demonstrate a beneficial effect of combining embolisation and irradiation in these patients. On the contrary, we observed more adverse effects with the combined treatment

Gemcitabine and Oxaliplatin Chemotherapy or Surveillance in Resected Biliary Tract Cancer (PRODIGE 12-ACCORD 18-UNICANCER GI): A Randomized Phase III Study

International audienceNo standard adjuvant treatment currently is recommended in localized biliary tract cancer (BTC) after surgical resection. We aimed to assess whether gemcitabine and oxaliplatin chemotherapy (GEMOX) would increase relapse-free survival (RFS) while maintaining health-related quality of life (HRQOL) in patients who undergo resection.Patients and methods: We performed a multicenter, open-label, randomized phase III trial in 33 centers. Patients were randomly assigned (1:1) within 3 months after R0 or R1 resection of a localized BTC to receive either GEMOX (gemcitabine 1,000 mg/m2 on day 1 and oxaliplatin 85 mg/m2 infused on day 2 of a 2-week cycle) for 12 cycles (experimental arm A) or surveillance (standard arm B). Primary end points were RFS and HRQOL.Results: Between July 2009 and February 2014, 196 patients were included. Baseline characteristics were balanced between the two arms. After a median follow-up of 46.5 months (95% CI, 42.6 to 49.3 months), 126 RFS events and 82 deaths were recorded. There was no significant difference in RFS between the two arms (median, 30.4 months in arm A v 18.5 months in arm B; hazard ratio [HR], 0.88; 95% CI, 0.62 to 1.25; P = .48). There was no difference in time to definitive deterioration of global HRQOL (median, 31.8 months in arm A v 32.1 months in arm B; HR, 1.28; 95% CI, 0.73 to 2.26; log-rank P = .39). Overall survival was not different (median, 75.8 months in arm A v 50.8 months in arm B; HR, 1.08; 95% CI, 0.70 to 1.66; log-rank P = .74). Maximal adverse events were grade 3 in 62% (arm A) versus 18% (arm B) and grade 4 in 11% versus 3% ( P < .001).Conclusion: There was no benefit of adjuvant GEMOX in resected BTC despite adequate tolerance and delivery of the regimen