Robust surface segmentation and edge feature lines extraction from fractured fragments of relics

AbstractSurface segmentation and edge feature lines extraction from fractured fragments of relics are essential steps for computer assisted restoration of fragmented relics. As these fragments were heavily eroded, it is a challenging work to segment surface and extract edge feature lines. This paper presents a novel method to segment surface and extract edge feature lines from triangular meshes of irregular fractured fragments. Firstly, a rough surface segmentation is accomplished by using a clustering algorithm based on the vertex normal vector. Secondly, in order to differentiate between original and fracture faces, a novel integral invariant is introduced to compute the surface roughness. Thirdly, an accurate surface segmentation is implemented by merging faces based on face normal vector and roughness. Finally, edge feature lines are extracted based on the surface segmentation. Some experiments are made and analyzed, and the results show that our method can achieve surface segmentation and edge extraction effectively

Examination of the ecohydrological separation hypothesis in a humid subtropical area: Comparison of three methods

© 2019 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (February 2019) in accordance with the publisher’s archiving policyThe ecohydrological separation between soil water sources for plant water uptake and groundwater recharge has been recently examined in various climate zones primarily based on isotopic composition of water. The existence of the ecohydrological separation has profound implications for mechanistic ecohydrological modeling and water resource management. However, it is still unclear when and where the ecohydrological separation occurs, especially in humid regions. In this study, high frequency sampling of precipitation, bulk soil water, groundwater and twig xylem water for hydrogen and oxygen isotope composition measurement was conducted in a humid subtropical site in the central southern China from March 2017 to April 2018. We examined evidence of the ecohydrological separation with three methods (dual-isotope space, line-conditioned excess (lc-excess), and the piecewise isotope balance (PIB) method). The results show that the isotopic composition of plant xylem and bulk soil water are not distinguishable from those of precipitation water on the dual-isotope space due to a weak evaporation effect at the study site, indicating that there is no evidence of the ecohydrological separation. However, the other two methods support the ecohydrological separation in this humid area, with the results from the PIB method revealing more temporal details. The present study suggests that the ecohydrological separation can happen in subtropical humid climate. It is more likely to occur in spring and winter at the study site when plant-accessible water pool has been replenished by antecedent precipitation, while ecohydrological connection seems to occur during winter snowmelt. With the limitations of three methods, the caution should be taken when only one method is applied in examining the ecohydrological separation in such an environment

Correlation between systemic immune inflammatory index and prognosis of patients with hepatic alveolar hydatid disease and establishment of a nomogram prediction model

BackgroundTo explore the evaluation value of systemic immune inflammation index (SII) in the prognosis of patients with alveolar hydatid disease, and establish a nomogram prediction model.MethodsCollect the clinical data of 351 patients undergoing hepatic alveolar hydatid surgery admitted to the Department of Hepatobiliary and Pancreatic Surgery, Affiliated Hospital of Qinghai University from January 2015 to December 2020, calculate the SII value, and use the receiver operating characteristic curve (ROC curve) to determine According to the optimal clinical cut-off value of SII, patients were divided into two groups with high SII and low SII, and the relationship between SII and clinicopathological factors and prognosis of patients with alveolar echinococcosis was analyzed. Establish a nomogram prediction model based on independent risk factors for patient prognosis, and evaluate the prediction accuracy and discrimination ability of the nomogram through the consistency index (C-index) and calibration curve. The result is through the use of bootstrapping validation with 1,000 re-sampling Method for internal verification.ResultsThe ROC curve was used to determine the optimal cut-off value of SII before operation 761.192, and patients were divided into low SII group (n = 184) cases and high SII group (n = 167) cases. The 1, 3, and 5-year survival rates of patients with hepatic alveolar hydatid in the low SII group and the high SII group were 98.90%, 96.90%, 86.50% and 98.20%, 72.50%, 40.30%, respectively. The survival rate of worm disease patients was significantly better than that of the high SII group, and the overall survival rate difference between the two groups was statistically significant (P < 0.001). Multivariate Cox regression model analysis results showed that intraoperative blood loss (HR = 1.810, 95%CI: 1.227–2.668, P = 0.003), SII (HR = 5.011, 95%CI: 3.052–8.228, P < 0.001), Complications (HR = 1.720, 95%CI: 1.162–2.545, P = 0.007) are independent risk factors for the prognosis of patients with alveolar hydatid disease. Draw a nomogram and include statistically significant factors in the multivariate Cox regression model to predict the overall survival rate of patients with alveolar hydatid disease at 1, 3, and 5 years. The survival probability calibration curve is displayed. The nomogram is compared with The actual results have a high degree of agreement. The concordance index (C-index) of the nomogram model in the modeling sample is 0.777, and the C-index in the verification sample is 0.797, indicating that the nomogram model of this study has good accuracy and discrimination.ConclusionsSII has a clear correlation to the prognosis of patients with alveolar echinococcosis. The nomogram prediction model constructed on this basis is beneficial to the clinically individualized analysis of the patient's prognosis

Surface states in bulk single crystal of topological semimetal Co3Sn2S2 toward water oxidation

The band inversion in topological phase matters bring exotic physical properties such as the topologically protected surface states (TSS). They strongly influence the surface electronic structures of the materials and could serve as a good platform to gain insight into the surface reactions. Here we synthesized high-quality bulk single crystals of Co3Sn2S2 that naturally hosts the band structure of a topological semimetal. This guarantees the existence of robust TSS from the Co atoms. Co3Sn2S2 crystals expose their Kagome lattice that constructed by Co atoms and have high electrical conductivity. They serves as catalytic centers for oxygen evolution process (OER), making bonding and electron transfer more efficient due to the partially filled orbital. The bulk single crystal exhibits outstanding OER catalytic performance, although the surface area is much smaller than that of Co-based nanostructured catalysts. Our findings emphasize the importance of tailoring TSS for the rational design of high-activity electrocatalysts

Explored potential hypoglycemic, hypolipidemic, and anti‐hyperuricemic components from Rheum tanguticum combing affinity ultrafiltration with four enzyme targets

Abstract Due to its variety of biological activities, rhubarb has been widely applied worldwide with a long history. However, the potential bioactive compounds in Rheum tanguticum responsible for hypoglycemic, hypolipidemic, and anti‐hyperuricemic activities as well as their underlying mechanisms remain elusive. In order to explore these specific multifunctional ingredients, the in vitro α‐glucosidase and pancreatic lipase inhibitory assays were first determined, and the results indicated that R. tanguticum possessed remarkable hypoglycemic and hypolipidemic activities. Then, 14, 23, 15, and 10 active compounds in R. tanguticum were fast screened out by employing the bio‐affinity ultrafiltration with LC‐MS (Liquid Chromatograph‐Mass Spectrometer) strategy, which displayed various binding abilities to α‐glucosidase, α‐amylase, lipase, and xanthine oxidase enzymes, respectively. Further verifications of potential bioactive ingredients were implemented by molecule docking and the enzyme inhibitory assays in vitro. At last, the first interaction network between multifunctional components in R. tanguticum and their targets was further constructed facilitating to decipher the underlying mechanisms of action regarding R. tanguticum. The present work suggests that R. tanguticum may be a promising natural therapeutics and have good potential to be developed to prevent and treat diabetes, obesity, and gout in the near future

Potential hypoglycemic and hypolipidemic bioactive constituents in Cyclocarya paliurus leaves explored by affinity ultrafiltration with α‐glucosidase and pancreatic lipase

Abstract Cyclocarya paliurus has been widely applied for therapeutic feeding as a traditional Chinese medicine homologous food with high nutritional and medical value. Nevertheless, the specific bioactive compounds liable for hypoglycemic and hypolipidemic properties and underlying mechanisms remain unexplored. In the present study, the in vitro hypoglycemic and hypolipidemic effects of C. paliurus were assessed by α‐glucosidase and pancreatic lipase inhibition assays, and the results indicated that 70% ethanol extract exhibited remarkable α‐glucosidase and pancreatic lipase inhibitory activity with the IC50 value of 3.14 μg/mL and 0.98 μg/mL, respectively. A total of 18 and 15 potential ligand candidates were screened, and the chemical structures were characterized. Furthermore, the docking result showed that chlorogenic acid, quercetin, kaempferol 3‐O‐rhamnoside, and pterocaryoside A contributed to the underlying hypoglycemic and hypolipidemic effects of C. paliurus, further strengthened the bindings of the enzyme‐ligand complex and suppressed the enzyme's activity with the binding energies ranged from −4.00 to −6.31 kcal/mol. The interrelations between the specific bioactive constituents, α‐glucosidase or lipase, and hypoglycemic or hypolipidemic activities were also carified. The present study reveals substantial prospects of C. paliurus to be developed as a natural dietotherapy, disease‐prevention, and healthcare for diabetes and obesity in the near future