Application of artificial neural networks to height transformation

Dvije su osnovne komponente vertikalnog pozicioniranja: visina i odgovarajuća referentna površina. Definicija visine se mijenja u skladu s odabranom referentnom površinom. Satelitski sustavi globalne navigacije (Global Navigation Satellite Systems - GNSS) daju elipsoidne visine razmjerne površini geodetski referentnog elipsoida. Međutim, mnoge aplikacije zahtijevaju visine koje su povezane s fizikalno značajnom površinom kao što je geoid. Takve visine su u obliku ortometrijskih (ili normalnih) visina. Veza između elipsoidnih i ortometrijskih visina je visina geoida iznad referentnog elipsoida, obično nazivana valovitim kretanjem geoida. Dva su osnovna pristupa kod pretvaranja elipsoidnih u ortometrijske visine: gravimetrijski model geoida i interpolacija između geometrijski deriviranih valovitih kretanja geoida gdje su GNSS mjerenja locirana uz nivelacijske točke. U ovom se radu istražuje korisnost umjetnih neuronskih mreža s unatražnim rasprostiranjem kao alternativni alat za transformaciju visine.The vertical positioning has two indispensable constituents: the height and the relevant reference surface. The definition of the height differs according to the appointed reference surface. Global Navigation Satellite Systems (GNSS) ensure ellipsoidal heights relative to a geodetic reference ellipsoid surface. However, many field applications require heights that are related to a physically meaningful surface (e.g. the geoid). Such physically meaningful heights often provided in terms of orthometric heights. The geoid undulation is the relation between the ellipsoidal and orthometric heights. The ellipsoidal heights can be transformed to orthometric heights via two principal approaches: a gravimetric geoid model, and geometrical interpolation between geoid undulations where GNSS observations have been collocated with benchmarks. The purpose of this study is investigating the applicability of a back propagation artificial neural network as a height transformation tool

THE EFFECT OF ALLERGIC CONJUCTIVITIS ON CHOROIDAL THICKNESS

Background: To examine the effects of allergic conjunctivitis and its treatment upon choroidal thickness (ChT) using topical antihistaminic agents. Methods: 60 eyes of 30 children and adolescents with allergic conjunctivitis and 60 eyes of 30 healthy controls participated in the study. Inclusion criteria for patient groups were best-corrected visual acuity 20/20 or better, normal intraocular pressure (IOP) and no systemic or ocular diseases other than allergic conjunctivitis. Healthy controls recruited from children and adolescents who had no ocular or chronic systemic disorders and had best-corrected visual acuity 20/20 or better and normal IOP. ChT was measuredby using Enhanced Depth Imaging Optical Coherence Tomography (EDI-OCT) before and after treatment by antihistamine agents. Results: Subfoveal choroidal thicknes mean value was 364.1±63.8 µm in the allergic conjunctivitis group and the first-month values after the treatment were 333.5± 52.1 µm. Subfoveal choroidal thickness means value in the control group was 320.6 ±80.9 µm. There was a statistically significant decrease in ChT after treatment of allergic conjunctivitis patients and there was a significant difference in terms of baseline ChT values between the allergic conjunctivitis group and the control group. There was no significant difference between one month after treatment values and the mean values of the control group. Conclusions: Our results demonstrate that ChT can increase in allergic conjunctivitis patients and can become normal again with topical antihistamine treatment. In order to support choroidal thickness to be a marker for the diagnosis and follow-up of allergic conjunctivitis, further studies with larger samples and longitudinal studies are needed

Hidatidinė kepenų cista ir vartų venos bei viršutinės pasaito arterijos: chirurginio gydymo galimybė

Hydatid cyst is a parasitic infestation by a tapeworm of the genus Echinococcus granulosus which can be localized in all vascularized tissues and causes cystic lesions. We present a case of hydatid liver cyst with portal vein and superior mesenteric artery invasion. Hydatid cysts are still commonly seen in Turkey. We believe that the most efficacious and least morbid treatment alternative for such rare complications of hydatid cysts is surgery.Turkijoje vis dar dažnos hidatidinės cistos. Tai parazito Echinococcus granulosus klinikinė manifestacija, kuri lokalizuojasi visuose vaskuliarizuotuose audiniuose ir sukelia cistinius darinius. Straipsnyje aptariamas hidatidinės kepenų cistos atvejis, apimantis kepenų vartų veną ir viršutinę pasaito arteriją. Daroma išvada, kad efektyviausias ir mažiausiai komplikacijų sukeliantis šios retos patologijos gydymas yra chirurgija

Chronic hepatitis B associated with hepatic steatosis, insulin resistance, necroinflammation and fibrosis.

Background: The effect of hepatitis B virus (HBV) infection on fatty liver disease is unclear.. Objectives: The aim of this study was to investigate the viral and host causes of fatty liver in chronic hepatitis B (CHB) patients. This study included 88 CHB patients of which 17 were not treated. Liver biopsy was performed in each patient. Group 1 included those with hepatic steatosis (n=28) and group 2 those without hepatic steatosis. The groups were compared in terms of age, body mass index (BMI), Homeostasis Model Assessment- Insulin Resistance (HOMA-IR), viral load, biochemical parameters and histological findings. Patients in group 1 were subdivided according to the degree of steatosis as follows: grade 1 (15 patients, 53.6%), grade 2 (6 patients, 21.4%),and grade 3 (7 patients, 25%). Results: In group 1 (n=28), mean age, BMI, cholesterol, and HOMA-IR were found to be significantly higher than in group 2 (n=60). There were no significant differences in the positivity of viral load, HbeAg, treatment, fibrosis and other laboratory parameters between the two groups. HOMA-IR was the only independent predictive factor of liver steatosis in patients with CHB in logistic regression analysis. Conclusion: Hepatic steatosis in CHB patients was associated with host metabolic factors

Phase Solubility Studies of Poorly Soluble Drug Molecules by Using O-Phosphorylated Calixarenes as Drug-Solubilizing Agents

WOS: 000298978900036This study is the first report on the solubilizing effect of O-phosphorylated calix[n]arenes that form complexes with neutral molecules such as nifedipine, niclosamide, and furosemide by host-guest complexation. These complexation studies were carried out by using the phase solubility technique. From the obtained results, it was observed that the solubility of guest molecules such as nifedipine, niclosamide, and furosemide was significantly increased in the presence of host molecules tetrakis-O-(diethoxyphosphoryl)-p-tert-butylcalix[4]arene (1), tetrakis-O-(diethoxyphosphoryl)-calix[4]arene (2), bis-O-(diethoxyphosphoryl)-p-tert-butylcalix[4]arene (3), bis-O-(diethoxyphosphoryl)-calix[4]arene (4), and octakis-O-(diethoxyphosphoryl)-p-tert-butylcalix[8]arene (5). The increase in solubility of drugs by the calixarene host 1 to 5 was most probably due to inclusion complexation between drug molecules and cavities of the calixarene skeleton similar to drug-cyclodextrin complexes.S.U. Research Foundation [BAP: 10101016]; Research Laboratory of Selcuk UniversityThe authors gratefully would like to thank S.U. Research Foundation (BAP: 10101016) for financial support.; The authors gratefully acknowledge support of this study produced from a part of the Ph.D. Thesis of Mevlut Bayrakci by the Research Laboratory of Selcuk University

Synthesis of new water-soluble phosphonate calixazacrowns and their use as drug solubilizing agents

WOS: 000306946700029This study presents the selective chloromethylation of calix[4](aza)crown ethers 2a-c, using chloromethyl n-octyl ether and SnCl4 in chloroform at room temperature in good yield for the first time. Chloromethylated products 2a-c are used as key intermediates to synthesize new water-soluble p-phosphonato calix[4](aza)crown ethers 5a-c. Liquid-liquid phase extraction and phase solubility studies with poor water soluble drug molecules such as nifedipine, niclosamide and furosemide are performed to evaluate their binding properties. Among the studied drugs, furosemide was the most effectively dissolved drug by p-phosphonato calix[4](aza)crown ethers 5a-c in water.S.U. Research Foundation [BAP: 10101016]This study is part of the PhD Thesis of Mevlut Bayrakci and the authors gratefully would like to thank S.U. Research Foundation (BAP: 10101016) for financial support

Solubilizing effect of the p-phosphonate calix[n]arenes towards poorly soluble drug molecules such as nifedipine, niclosamide and furosemide

WOS: 000306946700043This article reports the solubilization of the practically water insoluble drug molecules such as nifedipine, niclosamide and furosemide by guest:host inclusion complexation with p-phosphonates calix[n]arenes as drug soluble agent. This complexation studies were carried out by using the phase solubility technique. From the obtained results, it was observed that the solubility of drug molecules was significantly increased in the presence of calix[n]arene host molecules. The increase in solubility of drugs by the calix[n]arene was most probably due to inclusion complexation between drug molecules and cavities of the calixarene skeleton similar to drug:cyclodextrin complexes.S.U. Research Foundation [BAP: 10101016]This study is part of the PhD Thesis of Mevlut Bayrakci and the authors gratefully would like to thank S.U. Research Foundation (BAP: 10101016) for financial support

Transportation of Poorly Soluble Drug Molecules from the Organic Phase to the Aqueous Phase by Using Phosphorylated Calixarenes

WOS: 000297608800030This study is the first report on the extraction of poorly soluble drug molecules such as nifedipine, niclosamide, and furosemide from the organic phase to the aqueous phase by water-soluble p-phosphonate calix[n]arene receptors via a liquid-liquid phase extraction process. These water-soluble calixarene derivatives were easily obtained from the reaction between their corresponding chloromethylated derivatives and trimethyl phosphite. From the liquid-liquid phase extraction studies, it was observed that the size of the p-phosphonate calix[n]arenes changed the extraction percentage of selected drug molecules.S.U. Research Foundation [BAP: 10101016]The authors gratefully would like to thank S.U. Research Foundation (BAP: 10101016) for financial support

Removal of Phosphate Anions from Aqueous Solutions by Using Macrocyclic Receptors-Based Polyether, Lactone and Lactam Derivatives

WOS: 000288274600012In this study, the phosphate anions extraction efficiency of a series of receptors-based lactones 1a-d, 2, and 3, polyethers 4 and 5, lactam derivatives 6a-b, 7a-b, and 8a-d towards phosphate anion was evaluated by solvent extraction. It was observed that compounds 7a-b exhibited higher affinity toward phosphate ions than the other receptors. The extraction of phosphate anions by these compounds 7a-b indicates that the partially protonated amino groups play the major role for the formation of hydrogen bonds and electrostatic interactions at low pH. Furthermore, the effect of the polyethylene linkage and cavity of crown moieties on anion extraction was investigated. To evaluate the selectivity of receptors 6a-b and 7a-b, we also examined the retention of phosphate anions in the presence of Cl-, [image omitted], and [image omitted] anions at pH 1.5.Research Laboratory of Selcuk University; S. U. Research Foundation (BAP)The authors gratefully acknowledge support of this study by Research Laboratory of Selcuk University and thank S. U. Research Foundation (BAP) for financial support of this study