66 research outputs found
EVALUATION OF PHOTOPOLYMERIZABLE HEMA-BASED HYDROGELS FOR RELEASE OF ANTI-DIABETIC DRUG METFORMIN HCL
No full textThis study targets to prepare a metformin hydrochloride delivery system through the preparation and evaluation of 2-hydroxyl ethyl methacrylate (HEMA) based hydrogels. The current study explores the effect of photoinitiator (Irgacure 184, Irgacure 651), PEG-DA derivatives, 4-Acryloyl morpholine (4-AcM), and gelatine obtained by UV photopolymerization of HEMA hydrogels. Photopolymerization technique which was under UV irradiation was implemented at 365 nm and 300 s. Two different photoinitiators [2,2- Dimethoxy-2-phenyl-acetophenone (Irgacure 651)], [1-Hydroxycyclohexyl phenyl ketone (Irgacure 184)] were used to obtain the impact of photoinitiators on the metformin HCl release behavior of samples. In addition, PEG-DA Mn=258, PEG-DA Mn=700, 4-AcM, and gelatine were used to improve HEMA hydrogels. The prepared hydrogels have been characterized using Fourier transform infrared spectroscopy (FT-IR) and a digital microscope. The behaviors of hydrogels were specified by exploring swelling and release profiles in different medias. In-vitro metformin HCl release analyses have been done at pH 1.2, 6.8, and 7.4. UV-Vis spectrophotometer at 244 nm for releasing studies was used. The release results of hydrogels synthesized with Irgacure 651 demonstrated the majority quantity of the drug. Furthermore, the release amounts were higher in pH 1.2 than at mentioned pH medias before
Evaluation of Different Types of Paracetamol Active Pharmaceutical Ingredients' Effects on the Release System
No full textThe primary purpose of this study was to investigate the effect of active pharmaceutical ingredients (APIs) with varying particle sizes and properties on drug release and to develop matrix-type tablets based on poly(acrylic acid sodium salt) (PAANa) with different gelatin ratios for enhanced paracetamol release. Micronized, superfine, and purified paracetamol APIs were selected as model drugs to assess the impact of these APIs on drug release. Paracetamol is a frequently used medication in healthcare, so it is crucial to select the API with the optimal release rate and an economical, environmentally friendly production method. The direct compression method was employed in the preparation of the tablets due to its simplicity and ease of integration on an industrial scale. The release studies, release kinetics, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), physical properties, and microbial analyses (Escherichia coli, total mold, yeast) were investigated. The release studies at pH 1.2 and pH 7.4 revealed that the type of active pharmaceutical ingredient, especially micronized paracetamol API and superfine API, affects the paracetamol release ratio. Microbial analyses showed that produced tablets were convenient for health. In addition, prepared tablets with added gelatine can be used to deliver paracetamol with the desired release profile
Preparation and characterization of pH-sensitive hydrogels from photo-crosslinked poly(ethylene glycol) diacrylate incorporating titanium dioxide
No full textThe purpose of the present investigation was to prepare pH-sensitive hydrogels from photo-crosslinked poly(ethylene glycol) diacrylate (PEG-DA). Rutile titanium dioxide (TiO2) was employed to modify the PEG-DA hydrogels. The rutile titanium dioxide (TiO2) nanoparticles were prepared by direct oxidation of titanium in the presence of polyethylene glycol (PEG) at high temperature. The nanoparticles were characterized by FT-IR, XRD and SEM. The influence of experimental conditions, such as pH, type and amount of photoinitiators on the release profiles of donepezil hydrochloride (active pharmaceutical ingredient for Alzheimer disease) from modified PEG-DA hydrogels, was investigated. The drug release processes were analyzed kinetically using zero-order, first-order, Hixson-Crowell and Peppas models
Study on the preparation and drug release property of Modified PEG-DA based hydrogels
No full textThe aim of the present study is to develop hydroxyapatite modified PEG-DA and PEG-DA/HEMA based hydrogels for release of Donepezil HCl for potential treatment of Alzheimer’s disease. [2,2-Dimethoxy-2-phenyl-acetophenone] (Irgacure 651), 1 Hydroxycyclohexyl phenyl ketone (Irgacure 184) and 2-Hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959) were used as photo-initiators in the synthesis of hydrogels and hydroxyapatite was used for modifying hydrogels. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and digital microscope were utilized to investigate the characteristics properties of hydrogels. Photopolymerization technique was selected to synthesize for hydrogels. Swelling and drug release studies have been performed under different pH conditions
Synthesis and characterization of hydrogels based on poly(2-hydroxyethyl methacrylate) for drug delivery under UV irradiation
No full textThe present study aims to create a controlled release system through the preparation and characterization of hydrogels based on 2-hydroxyl ethyl methacrylate (HEMA). In order to investigate the influence of photo-initiators on the drug release behavior of the resulting hydrogels, three different photo-initiators [2,2-dimethoxy-2-phenyl-acetophenone] (Irgacure 651), 1-hydroxycyclohexyl phenyl ketone (Irgacure 184) and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959) were used. In addition, hydroxyapatite (HAp) was employed to modify HEMA hydrogels. The synthesis of hydrogels was confirmed by characterization through Fourier transform infrared spectroscopy, nuclear magnetic resonance (C-13 NMR) spectroscopy and digital microscope. The responsive behaviors were investigated by recording swelling ratios under different conditions. In vitro drug release studies were performed for donepezil hydrochloride-loaded hydrogels at pH 1.2, 6.8 and 7.4. The results indicated that hydrogels synthesized using Irgacure 2959 released the maximum amount of donepezil hydrochloride. Moreover, the release rate decreased in the presence of HAp
Ekimia ozcan-secmenii (Apiaceae), a new species from Southwest Anatolia, Turkey
No full textEkimia ozcan-secmenii Senol & Eroglu sp. nov. (Apiaceae) is described from SW Turkey. E. ozcan-secmenii differs from its close affinity, E. bornmuelleri, by life form (monocarpic), petal and bracteole morphology, and mericarp features. These data were more supported by the results of nrDNA ITS sequences. The ML tree depicted based on phylogenetic studies aimed to reveal the closeness of the Laserpitium and Prangos species as well as the location the affinity of species in the genus Ekimia. The taxonomic situation of Prangos hulusi was also evaluated based on nrDNA ITS sequences. Since E. ozcan-secmenii is distributed in Sami Soydam Sandalcik hydroelectric power plant in Acipayam, Denizli, the population is threatening by flooding. Therefore, conservation programs are urgently recommended.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-108T851]The author would like to thank the curators of GAZI and EGE Herbaria for their helpful assistance. We also thank Prof Dr Hayri Duman for his help and comments on the species. This research was financially supported by TUBITAK (TBAG-108T851)
Does neutrophil to lymphocyte ratio demonstrate deterioration in renal function?
No full textIntroduction: Chronic kidney disease (CKD) is a major health issue worldwide, which leads to end-stage renal failure and cardiovascular events. Neutrophil to lymphocyte ratio (NLR) is a surrogate marker of inflammation and has been widely studied in malignancies, hypertension, heart diseases, and vascular diseases. In this study, we aimed to investigate if NLR represents renal reserve and function after partial or radical nephrectomy. Methods: We conducted a retrospective study consists of patients who had undergone radical/partial nephrectomy in our hospital and/or who admitted to urology and nephrology clinics as an outpatient. Patients were divided into four groups: Group 1 (n = 46): Healthy controls; Group 2 (n = 50): Patients who had undergone unilateral partial nephrectomy; Group 3 (n = 46): Patients who had gone unilateral nephrectomy; Group 4 (n = 82): Patients who had CKD. Results: The mean NLR of each group was as follows: Group 1: 2.14 ± 0.73; Group 2: 3.52 ± 3.74; Group 3: 3.64 ± 3.52, and Group 4: 3.53 ± 2.30. NLR was lower in Group 1 compared to other groups but statistically significant difference was observed only between Group 1 (control) and Group 4 (CKD), 2.14 ± 0.73 versus 3.53 ± 2.30 (p = .005). In non-parametric correlation analysis NLR was found negatively correlated with GFR and positively correlated CKD stage (p = .028 for both correlations). Conclusions: The NLR may constitute a practical predictor of CKD besides Cr in patients who had undergone partial or radical nephrectomy
Disseminated Aspergillosis due to Aspergillus niger in Immunocompetent Patient: A Case Report
No full textInvasive aspergillosis is a major cause of morbidity and mortality in immunocompromised patients. Many cases of pulmonary, cutaneous, cerebral, and paranasal sinus aspergillosis in immunocompetent patient were defined in literature but disseminated aspergillosis is very rare. Here we present an immunocompetent case with extrapulmonary disseminated aspergillosis due to Aspergillus niger, totally recovered after effective antifungal treatment with voriconazole
Bibliometric Analysis of Concept Maps in Chemistry Education
No full textA comprehensive systematic review concerning the usage of concept maps in chemistry education (CMiCE) is not available in the literature. Therefore, this study attempts to conduct a systematic review of CMiCE using bibliometric analysis. Within the scope of the main aim of the study, articles related to CMiCE were searched on the Web of Science (WoS) database through the “ALL= (“concept* map*”) and ALL=(“chem*”) query. Data analysis was done using Microsoft Excel, VOSviewer software package and WoS analytical tool. According to the findings, information regarding trends, citation, co-authorship, co-word/co-occurrence, and co-citation in studies related to CMiCE were obtained. Results show that the most influential country was the USA, the most influential journal was the Journal of Chemical Education, the author with most citations was Novak, the most frequently used keyword was concept maps and the most commonly used keyword in recent years was the curriculum. The results from this study will contribute to other review studies related to CMiCE- especially in the context of chemistry education.</jats:p
Drivetrain integrated Dc-Dc converters utilizing zero sequence currents
No full textThe revolution of e-mobility has begun. With virtually every major player in automotive industry announcing e-versions of their product lines, or completely new electric models, along with increasing environmental awareness and public demand shifting towards sustainable transportation despite the discomfort; no one would disagree that the future of mobility is electric. However, the electric drivetrain is unlikely to push the internal combustion engines out of the market, at least for another few decades. It is predicted that, although close to 90% of passenger vehicles manufactured in 2030 will be electrified, more than 75% of these vehicles will still carry internal combustion engines. About half of the vehicles manufactured in 2030 will be mild hybrids, employing 48V networks for the electrification of the drivetrain. Along with ignition and traction assistance functions, most power consuming subsystems of the vehicle electronics are migrated to 48V to achieve higher efficiency levels and lower costs in these mild hybrid vehicles. On the other hand, it is both economically and technically more reasonable to keep the supply voltages of the low-power automotive electronics at 12V. Therefore, a stand-alone dc-dc converter is employed to supply the 12V network. A novel drivetrain with integrated dc-dc converter topology and a control algorithm has been proposed by the author, which enables power transfer between the 48V and 12V networks using the starter-generator and its inverter instead of a stand-alone dc-dc converter to save cost, weight and volume. Considering the production volume of the mild hybrid drivetrains in the next decade, eliminating this dc-dc converter can have a massive impact on the industry, not only through accelerating the adoption of 48V networks in higher classes, but also through enabling the adoption in lower class vehicles. The proposal may have a paradigm shifting effect, which may open the doors for mild hybrids to a whole new market of low budget vehicles. The drivetrain with integrated dc-dc converter consists of a synchronous machine and a conventional three phase inverter with an additional half bridge leg, which controls the zero sequence current across the machine. The zero sequence current is utilized to transfer power between the 48V and 12V networks. This power transfer is independent of the machine speed and torque; therefore, the integrated dc-dc converter can operate without any degradation on the operation range of the machine. It is shown in this thesis that the proposed drivetrain topology is functional and feasible. Experimental results, obtained from prototypes that employ machines with different stator and rotor geometries, show that the efficiency of the drivetrain with integrated dc-dc converter is comparable to a drivetrain with a stand-alone dc-dc converter throughout the whole operating range. Furthermore, contrary to common misconception, the presence of a small amount of zero sequence current neither saturates the core, nor generates significant losses
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