Search results for " Structures"
showing 10 items of 4162 documents
Computing Subdivision Surface Intersection
2003
Computer surface intersections is fundamental problem in geometric modeling. Any Boolean operation can be seen as an intersection calculation followed by a selection of parts necessary for building the surface of the resulting object. This paper deals with the computing of intersection curveson subdivision surfaces (surfaces generated by the Loop scheme). We present three variants of our algorithm. The first variant calculates this intersection after classification of the object faces into intersecting and non-intersecting pairs of faces. the second variant is based on 1-neighborhood of the intersecting faces. The third variant uses the concept of bipartite graph.
Synthesis and Antitumor Evaluation of Menthone-Derived Pyrimidine-Urea Compounds as Potential PI3K/Akt/mTOR Signaling Pathway Inhibitor.
2022
A series of novel menthone derivatives bearing pyrimidine and urea moieties was designed and synthesized to explore more potent natural product-derived antitumor agents. The structures of the target compounds were confirmed by FTIR, NMR, and HRMS. The in vitro antitumor activity was tested by standard methyl thiazolytetrazolium assay and showed that 4i, 4g, 4s, and 4m are the best compounds with IC50 values of 6.04 ± 0.62µM, 3.21 ± 0.67µM, 19.09 ± 0.49µM, and 18.68 ± 1.53µM, against Hela, MGC-803, MCF-7, and A549, respectively. The results of the preliminary action mechanism studies showed that compound 4i, the representative compound, could induce cell apoptosis in Hela cells in a dose-dep…
Hyperspectral Imaging of Macroinvertebrates : a Pilot Study for Detecting Metal Contamination in Aquatic Ecosystems
2018
The applicability of spectral analysis in detection of freshwater metal contamination was assessed by developing and testing a novel hyperspectral imaging (HSI) application for aquatic insect larvae (Trichoptera: Hydropsychidae). Larvae were first exposed to four different cadmium (Cd) concentrations: 0, 1, 10, and 100 μg L−1 for 96 h. Individual larvae were then preserved in ethanol, inspected with microscopy for the number of anomalies in larval gills, and imaged by hyperspectral camera operating with wavebands between 500 and 850 nm. Three additional larvae from each exposure were analyzed for tissue Cd concentration. Although the larval tissue Cd concentrations correlated positively wit…
Enterobacter cloacae administration induces hepatic damage and subcutaneous fat accumulation in high-fat diet fed mice.
2018
Accumulating evidence indicates that gut microbiota plays a significant role in obesity, insulin resistance and associated liver disorders. Family Enterobacteriaceae and especially Enterobacter cloacae strain B29 have been previously linked to obesity and hepatic damage. The underlying mechanisms, however, remain unclear. Therefore, we comprehensively examined the effects of E. cloacae subsp. cloacae (ATCC® 13047™) administration on host metabolism of mice fed with high-fat diet (HFD). C57BL/6N mice were randomly divided into HFD control, chow control, and E. cloacae treatment groups. The E. cloacae treatment group received live bacterial cells in PBS intragastrically twice a week, every ot…
Attēla kvalitātes ietekme uz acs struktūru izvērtēšanu foto-diagnostikā
2021
Darba mērķis bija izpētīt 18 samazinātas kvalitātes spraugas lampas attēlu, kuros attēloti acu priekšējo daļu struktūras, ietekmi uz 5 profesionāļu atzinumiem. Attēli, kas sadalīti 3 6 attēlu komplektos trim samazināšanas filtriem, izplūdums (1-6), troksnis (7-12) un kontrasts (13-18), tika parādīti datora ekrānā un salīdzināti ar oriģinālajiem attēliem. Rezultāti tika saskaņoti ar īsto attēla diagnozi un novērtēti 3 punktu sistēmā, pareizs atradums: 1 un 0,5 (daļēji) punkti, nepareizs vai nav atrasts: 0 punkti. Tika reģistrēti 53 punkti no 90 (58% pareizi un 41% nepareizi). Rezultāti liecina, ka attēla kvalitātes samazināšana būtiski neietekme…
Complex multilayer carbon structures for green energetics
2017
The authors greatly acknowledge the IMIS2 project of the National Reform Programme of Latvia for financial support. The publication costs of this article were covered by the Estonian Academy of Sciences and the University of Tartu.
Photoinduced lethal and sublethal toxicity of retene, a polycyclic aromatic hydrocarbon derived from resin acid, to coregonid larvae
2004
A comparative investigation on the acute phototoxicity of retene to vendace (Coregonus albula) and whitefish (C. lavaretus), both having pelagial larvae in spring, was conducted. To test the concept of early warning of sublethal biomarkers in relation to lethality to posthatch stages, we examined the effects of ultraviolet-B (UV-B) and retene on the levels of cytochrome P4501A (CYP1A) and heat shock protein 70 (HSP70) by exposing the animals to elevated levels of these factors for 48 and 72 h, respectively. Whereas UV-B and retene on their own were not lethal, simultaneous retene and UV-B exposure caused very high mortality to both species. The median lethal concentration (LC50; i.e., the c…
Choroidal thickness in glaucoma patients and glaucoma suspects measured by spectral domain coherence optical tomography
2012
Purpose: The aim of our study was to evaluate and compare retro-foveolar choroidal thickness (RFCT) of healthy subjects, individuals with intraocular hypertension, patients with primary open-angle glaucoma (POAG), patients with normal tension glaucoma (NTG) and patients with primary angle-closure glaucoma (PACG) by spectral domain optical coherence tomography (SD-OCT).Methods: Sixty-five healthy eyes, 30 eyes with intraocular hypertension, 90 eyes with POAG, 30 eyes with NTG and 20 eyes with PACG were included in this cross-sectional study. RFCT, foveolar retinal thickness and average retinal nerve fiber layer thickness (RNFL) were measured by SD-OCT (Spectralis HRA-OCT, Heidelberg Engineer…
Retinal Vascular Assessment in Psoriasis: A Multicenter Study
2021
PurposeTo investigate the vascular status of the macula in psoriasis patients without history of ocular inflammation by Optical Coherence Tomography Angiography (OCTA).MethodsThis prospective cross-sectional multicenter study included 55 psoriasis patients and 55 control healthy subjects. A complete eye examination and 6 mm × 6 mm OCTA imaging were performed. Retinal vascular status was evaluated by analyzing vascular density (VD) of superficial vascular plexus (superficial wVD) and deep vascular plexuses (deep wVD) in a 6 mm × 6 mm area and in foveal (superficial fVD and deep fVD) and parafoveal sectors (superficial pVD and deep pVD). In addition, foveal thickness (FT) and foveal avascular…
Maintenance of anticoagulant and antiplatelet agents for patients undergoing vitreoretinal surgery
2009
International audience; Purpose: To establish the prevalence of anticoagulant, aspirin, and clopidogrel use in patients undergoing vitreoretinal surgery, and to compare the outcome of peribulbar anesthesia between users and non-users. Materials and Methods: We conducted a retrospective case series in one academic center between January and June 2009. We analyzed the chart of 239 eyes who underwent posterior segment surgery with peribulbar anesthesia. Data included age, reasons for anticoagulant and/or antiplatelet agents, operative procedure, history of diabetes mellitus, high blood pressure, axial globe length, pre and post operative visual acuity, complications rates during and after anes…