1,794 research outputs found

    Mehanizam akutne neurotoksičnosti u Sprague-Dawley štakora izazvane trovanjem endosulfanom

    Get PDF
    The purpose of this study was to investigate the molecular mechanism underlying oxidative and inflammatory neuronal cell death induced by endosulfan, a pesticide belonging to the chemical family of organochlorines. The cortical and hippocampal tissues derived from Sprague-Dawley (SD) rats treated with endosulfan exhibited increased intracellular accumulation of reactive oxygen species and oxidative damages to cellular macromolecules such as depletion of glutathione, lipid peroxidation, and protein carbonylation. Conversely, the expression of antioxidant enzymes including γ-glutamylcysteine ligase (GCL), superoxide dismutase (SOD), and heme oxygenase-1 (HO-1) was markedly reduced in the brain tissues exposed to endosulfan. Moreover, during endosulfan-induced neuronal cell death, mRNA expression of pro-inflammatory cytokines such as tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) was elevated, which seemed to be mediated by the activation of nuclear factor-kappa B (NF-κB) by phosphorylation of p65 subunit. These results suggest a new molecular mechanism underlying the endosulfan-induced acute neurotoxicity via induction of oxidative stress and pro-inflammatory responses.Istražen je molekularni mehanizam koji dovodi do smrti neurona potaknute oksidativnim i upalnim procesima uzrokovanim organoklornim pesticidom endosulfanom. U tkivima korteksa i hipokampusa Sprague-Dawley (SD) štakora tretiranih endosulfanom uočena su oksidativna oštećenja staničnih makromolekula, poput smanjene razine glutationa, lipidne peroksidacije i karbonilacije proteina, te povećane unutarstanične akumulacije reaktivnih kisikovih spojeva. Isto tako, u moždanom tkivu nakon izlaganja endosulfanu značajno je smanjena ekspresija enzimskih antioksidansa, uključujući i γ-glutamilcistein ligazu (GCL), superoksidnu dismutazu (SOD) i hem oksigenazu-1 (HO-1). Tijekom endosulfanom izazvane smrti neurona povećala se i ekspresija mRNA pro-upalnih citokina poput čimbenika nekroze tumora-α (TNF-α) i interleukina-1β (IL-1β), što je čini se bilo posredovano aktivacijom nuklearnoga faktora kapa B (NF-κB) putem fosforilacije podjedinice p65. Navedeni rezultati upućuju na novi molekularni mehanizam koji stoji iza akutne neurotoksičnosti izazvane endosulfanom putem indukcije oksidativnoga stresa i pro-upalnih odgovora

    A hybrid decision support model to discover informative knowledge in diagnosing acute appendicitis

    Get PDF
    BACKGROUND: The aim of this study is to develop a simple and reliable hybrid decision support model by combining statistical analysis and decision tree algorithms to ensure high accuracy of early diagnosis in patients with suspected acute appendicitis and to identify useful decision rules. METHODS: We enrolled 326 patients who attended an emergency medical center complaining mainly of acute abdominal pain. Statistical analysis approaches were used as a feature selection process in the design of decision support models, including the Chi-square test, Fisher's exact test, the Mann-Whitney U-test (p < 0.01), and Wald forward logistic regression (entry and removal criteria of 0.01 and 0.05, or 0.05 and 0.10, respectively). The final decision support models were constructed using the C5.0 decision tree algorithm of Clementine 12.0 after pre-processing. RESULTS: Of 55 variables, two subsets were found to be indispensable for early diagnostic knowledge discovery in acute appendicitis. The two subsets were as follows: (1) lymphocytes, urine glucose, total bilirubin, total amylase, chloride, red blood cell, neutrophils, eosinophils, white blood cell, complaints, basophils, glucose, monocytes, activated partial thromboplastin time, urine ketone, and direct bilirubin in the univariate analysis-based model; and (2) neutrophils, complaints, total bilirubin, urine glucose, and lipase in the multivariate analysis-based model. The experimental results showed that the model with univariate analysis (80.2%, 82.4%, 78.3%, 76.8%, 83.5%, and 80.3%) outperformed models using multivariate analysis (71.6%, 69.3%, 73.7%, 69.7%, 73.3%, and 71.5% with entry and removal criteria of 0.01 and 0.05; 73.5%, 66.0%, 80.0%, 74.3%, 72.9%, and 73.0% with entry and removal criteria of 0.05 and 0.10) in terms of accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and area under ROC curve, during a 10-fold cross validation. A statistically significant difference was detected in the pairwise comparison of ROC curves (p < 0.01, 95% CI, 3.13-14.5; p < 0.05, 95% CI, 1.54-13.1). The larger induced decision model was more effective for identifying acute appendicitis in patients with acute abdominal pain, whereas the smaller induced decision tree was less accurate with the test data. CONCLUSIONS: The decision model developed in this study can be applied as an aid in the initial decision making of clinicians to increase vigilance in cases of suspected acute appendicitis

    Fully automatic integration of dental CBCT images and full-arch intraoral impressions with stitching error correction via individual tooth segmentation and identification

    Full text link
    We present a fully automated method of integrating intraoral scan (IOS) and dental cone-beam computerized tomography (CBCT) images into one image by complementing each image's weaknesses. Dental CBCT alone may not be able to delineate precise details of the tooth surface due to limited image resolution and various CBCT artifacts, including metal-induced artifacts. IOS is very accurate for the scanning of narrow areas, but it produces cumulative stitching errors during full-arch scanning. The proposed method is intended not only to compensate the low-quality of CBCT-derived tooth surfaces with IOS, but also to correct the cumulative stitching errors of IOS across the entire dental arch. Moreover, the integration provide both gingival structure of IOS and tooth roots of CBCT in one image. The proposed fully automated method consists of four parts; (i) individual tooth segmentation and identification module for IOS data (TSIM-IOS); (ii) individual tooth segmentation and identification module for CBCT data (TSIM-CBCT); (iii) global-to-local tooth registration between IOS and CBCT; and (iv) stitching error correction of full-arch IOS. The experimental results show that the proposed method achieved landmark and surface distance errors of 112.4 μ\mum and 301.7 μ\mum, respectively

    Prediction of steel plate deformation due to triangle heating using the inherent strain method

    Full text link
    In a shipyard, line heating and triangle heating are two major processes carried out by skilled workers to form curved plates in various shapes under various heating conditions. There have been many studies on line heating, but triangle heating has rarely been studied owing to its complicated heating process with irregular multiheating paths and highly concentrated heat input. Triangle heating is the most labor-intensive job. Hence, it is essential for most shipyards to study the automation, as well as the improvement, of the triangle heating process in order to increase hull-forming productivity. In this study, a pioneering attempt to simulate triangle heating was made. A circular disk-spring model is proposed as an analysis model for the elastoplastic procedure of triangle heating, and the inherent strain method is also used to analyze the deformation of plates. The results of the simulation were compared with those of experiments and showed good agreement. It is shown that the present approach and the model used in this study are effective and efficient for simulating triangle heating for the steel plate forming process in shipbuilding.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41591/1/773_2005_Article_202.pd

    A Newly Formed and Ruptured Atheromatous Plaque within Neointima after Drug-Eluting Stent Implantation: 2-Year Follow-Up Intravascular Ultrasound and Optical Coherence Tomography Studies

    Get PDF
    Late stent thrombosis (LST) which is a life threatening complication has emerged as a serious problem of drug-eluting stents (DES). Several studies have suggested that incomplete neointimal coverage of stent struts contributes to LST. Progressive atherosclerosis within the neointima is an another possible cause of LST, but this phenomenon has seldom been reported in DES. We present a case of LST following DES implantation after a period of 28 months due to ruptured atheromatous plaque, despite complete neointimal coverage of stent struts proven by optical coherence tomography

    Enhancing exciton diffusion in monolayer WS2 with h-BN bottom layer

    Get PDF
    We investigated two-dimensional (2D) exciton diffusion in monolayer WS2 on both SiO2 and hexagonal boron nitride (h-BN) layers to identify the exciton diffusion enhanced by the h-BN bottom layer using spatially resolved photoluminescence imaging combined with time-resolved spectroscopy. The WS2 on the h-BN bottom layer shows an exciton diffusion coefficient of 38cm2/s, which is almost 1.7 times that of WS2 on the SiO2 layer. Electrostatic force microscopy confirms that the increase in the 2D exciton diffusion is mainly due to the reduction in the charge impurities and traps on the h-BN surface compared to the SiO2 surface. © 2019 American Physical Society.1
    corecore