IDENTIFICATION OF TREATED-COLOR FRESHWATER CULTURED PEARLS

Ta τελευταία 30 χρόνια η ζήτηση των χρωματιστών μαργαριταριών (όπου είναι σπανιότερα από τα λευκά) έχει ανέβει κατακόρυφα. Αποτέλεσμα αυτού είναι η εισροή στην αγορά μαργαριταριών με τεχνητό χρώμα, η αναγνώριση των οποίων απασχολεί έντονα τους γεμμολόγους. Για την αναγνώριση, τα μαργαριτάρια εξετάζονται μακροσκοπικά και μικροσκοπικά, γίνονται μετρήσεις φθορισμού σε ακτίνες-Χ (EDXRF) και τέλος μελετώνται οι ακτινογραφίες τους. Με τη χρήση ωστόσο των παραπάνω μεθόδων δεν καθίσταται, πάντα, εφικτή η αναγνώριση των τεχνητά χρωματισμένων μαργαριταριών. Παλαιότερες έρευνες έδειξαν ότι η φασματοσκοπία Raman είναι χρήσιμη στην αναγνώριση των χρωστικών ουσιών των μαργαριταριών γλυκού νερού. Στη παρούσα εργασία παρουσιάζονται μετρήσεις του φαινομένου Raman, με τη χρήση πράσινου laser, σε 35 φυσικά και 15 τεχνητά χρωματισμένα δείγματα. Όλα τα φάσματα Raman των φυσικά χρωματισμένων δειγμάτων παρουσιάζουν δύο κορυφές, όπου είναι χαρακτηριστικές για τις πολυακετυλενικές χρωστικές ουσίες. Αυτές οι κορυφές είναι παρούσες, ανεξαρτήτως του χρώματος των δειγμάτων, και οφείλονται στη δόνηση τάσης (stretching) των μορίων του των διπλών δεσμών άνθρακα (C—C) -στα 1530(±25) cm'1- και των μονών δεσμών άνθρακα (CC) -στα 1130(±10) cm'1- των χρωστικών ουσιών. Στη παρούσα εργασία προτείνεται ότι  η πιθανή απουσία των παραπάνω κορυφών Raman σε ένα χρωματιστό μαργαριτάρι γλυκού νερού αποτελεί απόδειξη ότι το χρώμα του μαργαριταριού αυτού είναι τεχνητό.Demand for colored pearls has grown during the last thirty years. Colored pearls are rarer than white ones. Thus treated-color pearls have entered the marketplace and their identification became a challenge for the gemologists. With only the help of visual observation, EDXRF and X-radiography, methods that are used today for pearls identification, it is not always easy to identify them. Previous studies, have established that Raman scattering is useful to detect pigments in cultured freshwater pearls. The present study is based on the measurement of the Raman spectroscopy of 35 natural colored freshwater pearls and 15 treated-color freshwater pearls, covering a wide range of typical colors for this material, with green excitation. All natural- color pearls show the two major Raman resonance features of polacetyenic pigments assigned to C=C stretching-at about 1530(±25) cm'1- and C-C stretching - at about 1130(±10) cm' -, regardless of their specific hue. In this paper it is proposed that the absence of these Raman features prove the artificial origin of pigments in a colored freshwater cultured pearl

Towards a Semantic Gas Source Localization under Uncertainty

Towards a Semantic Gas Source Localization under Uncertainty.Communications in Computer and Information Science book series (CCIS, volume 855), doi:10.1007/978-3-319-91479-4_42This work addresses the problem of efficiently and coherently locating a gas source in a domestic environment with a mobile robot, meaning efficiently the coverage of the shortest distance as possible and coherently the consideration of different gas sources explaining the gas presence. The main contribution is the exploitation, for the first time, of semantic relationships between the gases detected and the objects present in the environment to face this challenging issue. Our proposal also takes into account both the uncertainty inherent in the gas classification and object recognition processes. These uncertainties are combined through a probabilistic Bayesian framework to provide a priority-ordered list of (previously observed) objects to check. Moreover the proximity of the different candidates to the current robot location is also considered by a cost function, which output is used for planning the robot inspection path. We have conducted an initial demonstration of the suitability of our gas source localization approach by simulating this task within domestic environments for a variable number of objects, and comparing it with an greedy approach.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Survey of current practices and opinions of German Society of Gynecologic Endoscopy members regarding the treatment of ovarian neoplasia by robotic surgery

Purpose As data on this topic are sparse and contradictory, we aimed to ascertain the opinions of the members of the German Society of Gynecologic Endoscopy (AGE) regarding the use of robotic surgery in the treatment of ovarian malignancies. Methods In 2015, an anonymous questionnaire was sent to AGE members to assess their views on the treatment of ovarian malignancies by robotic surgery according to T stage and the current treatment practices in their facilities. Results Of the 228 respondents, 132 (58%) were fellows or attending physicians and 156 (68%) worked at university hospitals or tertiary referral centers. Most [n = 218 (96%)] respondents reported treating < 10% of their patients using robotic surgery. Respondents felt that T1 and borderline ovarian tumors, but not T2 (51%) or T3/4 (76%) tumors, should and could be treated by robot surgery. 162 (71%) respondents considered the currently available data on this subject to be insufficient, and 42% indicated their willingness to participate in clinical studies on the applicability of robotic surgery to the treatment of T1/2 ovarian tumors. Conclusion The majority of AGE members surveyed considered robotic surgery to be an option for the treatment of T1 ovarian malignancies and borderline ovarian tumors. However, prospective randomized studies are needed to determine the relevance of robotic surgery in this context

Intraoperative and postoperative complications of gynecological laparoscopic interventions: incidence and risk factors

Purpose The aims of this study were to determine the incidence of intraoperative and postoperative complications of laparoscopic gynecological interventions and to identify risk factors for such complications. Methods All patients who underwent laparoscopic interventions from September 2013 to September 2017 at the Department of Gynecology, Obstetrics and Reproductive Medicine, Saarland University Hospital were identified retrospectively using a prospectively compiled clinical database. Binary logistic regression analysis was used to identify independent risk factors for intra- and postoperative complications. Results Data from 3351 patients were included in the final analysis. Overall, 188 (5.6%) intraoperative and 219 (6.5%) postoperative complications were detected. On multivariate analysis, age [odds ratio (OR), 1.03; 95% confidence interval (CI) 1.01–1.04], surgery duration (OR, 1.02; 95% CI 1.02–1.03), carbon dioxide use (OR, 0.99; 95% CI 0.99–1.00), and surgical indication (all p ≤ 0.01) were independent risk factors for intraoperative and duration of surgery (OR, 1.01; 95% CI 1.01–1.02; p ≤ 0.01), carbon dioxide use (OR, 0.99; 95% CI 0.99–1.00; p ≤ 0.01), hemoglobin drop (OR, 1.41; 95% CI 1.21–1.65; p ≤ 0.01), and ASA status (p = 0.04) for postoperative complications. Conclusion In this large retrospective analysis with a generally low incidence of complications (5.6% intraoperative and 6.5% postoperative complications), a representative risk collective was identified: Patients aged > 38 years, surgery duration > 99 min, benign or malignant adnex findings were at higher risk for intraoperative and patients with surgery duration > 94 min, hemoglobin drop > 2 g/dl and ASA status III at higher risk for postoperative complications

Liver phenotypes in PCOS : Analysis of exogenous and inherited risk factors for liver injury in two European cohorts

Background & Aims Fatty liver disease (FLD) is common in women with polycystic ovary syndrome (PCOS). Here, we use non-invasive tests to quantify liver injury in women with PCOS and analyse whether FLD-associated genetic variants contribute to liver phenotypes in PCOS. Methods Prospectively, we recruited women with PCOS and controls at two university centres in Germany and Poland. Alcohol abuse was regarded as an exclusion criterion. Genotyping of variants associated with FLD was performed using TaqMan assays. Liver stiffness measurements (LSM), controlled attenuation parameters (CAP) and non-invasive HSI, FLI, FIB-4 scores were determined to assess hepatic steatosis and fibrosis. Results A total of 42 German (age range 18–53 years) and 143 Polish (age range 18–40 years) women with PCOS, as well as 245 German and 289 Polish controls were recruited. In contrast to Polish patients, Germans were older, presented with more severe metabolic profiles and had significantly higher LSM (median 5.9 kPa vs. 3.8 kPa). In the German cohort, carriers of the PNPLA3 p.I148M risk variant had an increased LSM (p = .01). In the Polish cohort, the minor MTARC1 allele was linked with significantly lower serum aminotransferases activities, whereas the HSD17B13 polymorphism was associated with lower concentrations of 17-OH progesterone, total testosterone, and androstenedione (all p < .05). Conclusions FLD is common in women with PCOS. Its extent is modulated by both genetic and metabolic risk factors. Genotyping of variants associated with FLD might help to stratify the risk of liver disease progression in women suffering from PCOS