50 research outputs found

    Conceptual design of an e-marketplace for small and medium enterprises in the Turkish machinery industry

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    This paper reports on the results of a study carried out in the Turkish machinery industry. The purpose of the study was to identify the benefits the sector can seize from e-business and to develop a conceptual framework for potential e-business applications. We analysed the current state of e-business use in the machinery industry in order to understand the future requirements and application opportunities and to come up with a conceptual e-business design that would suit both the needs and the characteristics of the sector. The study included those companies, which are members of the Machine Manufacturers’ Association (MMA) in Turkey. Information about the existing applications and future requirements was obtained from the results of a survey conducted among the member companies. Statistically adequate number of responses was obtained to make the results representative of the machine industry. Web sites of the member companies were also reviewed for further information gathering. Results indicated that most of the companies are Small and Medium Enterprises(SME) and it would be better for them to carry out certain operations through an e-market specifically designed for the sector. The proposed conceptual e-market design is based on the characteristics of the industry emerging from the survey

    The Effect of Admission Creatinine Levels on One-Year Mortality in Acute Myocardial Infarction

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    Background. We have known that patients with renal insufficiency (creatinine level) have increased mortality for coronary artery disease. In this study, the relationship between admission creatinine level and one year mortality are evaluated in patients with acute myocardial infarction (AMI). Method. 160 AMI patients (127 men and 33 women with a mean age of 59 ± 13) were enrolled in the study. Serum creatinine levels were measured within 12 hours of AMI. The patients were divided into two groups according to admission serum creatinine level. (1) elevated group (serum creatinine > 1.3 mg/dL) and (2) normal group (≤1.3 mg/dL). One year mortality rates were evaluated. Results. Elevated serum creatinine is observed in the 27 patients (16.9%). The mean creatinine level is 1.78 ± 7 mg/dL in the elevated group and 0.9 ± 0.18 mg/dL in the normal group (P < 0.0001). The mortality rate of the elevated group (n = 7, 25.9%) is higher than that of the normal group (n = 9, 6.8%). A significant increase in one year mortality is also observed (P=002) 60. Conclusion. The mildly elevated admission serum creatinine levels are markedly increased to one year mortality in patients with AMI

    Left Atrial Myxoma With Pleural Effusion

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    Cardiac myxomas are histologically benign tumors but they may be lethal because of their strategic position. They have variable presentations and excellent prognosis after surgical excision. Left atrial myxomas may mimic mitral stenosis and is very rarely associated with pleural effusion. We presented a case of left atrial myxoma blocking mitral orifice and causing recurrent pulmonary edema and pleural effusions in this report

    Fabrication and optimization of 3D printed gelatin methacryloyl microneedle arrays based on vat photopolymerization

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    Microneedles (MNs) are micrometer-sized arrays that can penetrate the skin in a minimally invasive manner; these devices offer tremendous potential for the transdermal delivery of therapeutic molecules. Although there are many conventional techniques for manufacturing MNs, most of them are complicated and can only fabricate MNs with specific geometries, which restricts the ability to adjust the performance of the MNs. Herein, we present the fabrication of gelatin methacryloyl (GelMA) MN arrays using the vat photopolymerization 3D printing technique. This technique allows for the fabrication of high-resolution and smooth surface MNs with desired geometries. The existence of methacryloyl groups bonded to the GelMA was verified by 1H NMR and FTIR analysis. To examine the effects of varying needle heights (1000, 750, and 500 µm) and exposure times (30, 50, and 70 s) on GelMA MNs, the height, tip radius, and angle of the needles were measured; their morphological and mechanical properties were also characterized. It was observed that as the exposure time increased, the height of the MNs increased; moreover, sharper tips were obtained and tip angles decreased. In addition, GelMA MNs exhibited good mechanical performance with no breakage up to 0.3 mm displacement. These results indicate that 3D printed GelMA MNs have great potential for transdermal delivery of various therapeutics

    Changes in Serum Natriuretic Peptide Levels after Percutaneous Closure of Small to Moderate Ventricular Septal Defects

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    Background. B-type natriuretic peptide has been shown to be a very sensitive and specific marker of heart failure. In this study, we aimed to investigate the effect of percutaneous closure of ventricular septal defects with Amplatzer septal occluders on brain natriuretic peptide levels. Methods. Between 2008 and 2011, 23 patients underwent successfully percutaneous ventricular septal defect closure in 4 cardiology centers. Brain natriuretic peptide levels were measured in nine patients (4 male, mean ages were 25.3 ± 14.3) who underwent percutaneous closure with Amplatzer occluders for membranous or muscular ventricular septal defects were enrolled in the study. Brain natriuretic peptide levels were measured one day before and one month after the closure. Patients were evaluated clinically and by echocardiography one month after the procedure. Results. Percutaneous closures of ventricular septal defects were successfully performed in all patients. There was not any significant adverse event in patients group during followup. Decrease in brain natriuretic peptide levels after closure were statistically significant (97.3 ± 78.6 versus 26.8 ± 15.6, P = 0.013). Conclusion. Brain Natriuretic Peptide levels are elevated in patients with ventricular septal defects as compared to controls. Percutaneous closure of Ventricular Septal Defect with Amplatzer occluders decreases the BNP levels

    Three-Dimensional-Printed GelMA-KerMA Composite Patches as an Innovative Platform for Potential Tissue Engineering of Tympanic Membrane Perforations

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    Tympanic membrane (TM) perforations, primarily induced by middle ear infections, the introduction of foreign objects into the ear, and acoustic trauma, lead to hearing abnormalities and ear infections. We describe the design and fabrication of a novel composite patch containing photocrosslinkable gelatin methacryloyl (GelMA) and keratin methacryloyl (KerMA) hydrogels. GelMA-KerMA patches containing conical microneedles in their design were developed using the digital light processing (DLP) 3D printing approach. Following this, the patches were biofunctionalized by applying a coaxial coating with PVA nanoparticles loaded with gentamicin (GEN) and fibroblast growth factor (FGF-2) with the Electrohydrodynamic Atomization (EHDA) method. The developed nanoparticle-coated 3D-printed patches were evaluated in terms of their chemical, morphological, mechanical, swelling, and degradation behavior. In addition, the GEN and FGF-2 release profiles, antimicrobial properties, and biocompatibility of the patches were examined in vitro. The morphological assessment verified the successful fabrication and nanoparticle coating of the 3D-printed GelMA-KerMA patches. The outcomes of antibacterial tests demonstrated that GEN@PVA/GelMA-KerMA patches exhibited substantial antibacterial efficacy against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Furthermore, cell culture studies revealed that GelMA-KerMA patches were biocompatible with human adipose-derived mesenchymal stem cells (hADMSC) and supported cell attachment and proliferation without any cytotoxicity. These findings indicated that biofunctional 3D-printed GelMA-KerMA patches have the potential to be a promising therapeutic approach for addressing TM perforations

    3D Propolis-Sodium Alginate Scaffolds: Influence on Structural Parameters, Release Mechanisms, Cell Cytotoxicity and Antibacterial Activity

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    FEN-C-YLP-130319-0065 BAPKO Project. UID/CTM/50025/2019In this study, the main aim was to fabricate propolis (Ps)-containing wound dressing patches using 3D printing technology. Different combinations and structures of propolis (Ps)-incorporated sodium alginate (SA) scaffolds were developed. The morphological studies showed that the porosity of developed scaffolds was optimized when 20% (v/v) of Ps was added to the solution. The pore sizes decreased by increasing Ps concentration up to a certain level due to its adhesive properties. The mechanical, swelling-degradation (weight loss) behaviors, and Ps release kinetics were highlighted for the scaffold stability. An antimicrobial assay was employed to test and screen antimicrobial behavior of Ps against Escherichia coli and Staphylococcus aureus strains. The results show that the Ps-added scaffolds have an excellent antibacterial activity because of Ps compounds. An in vitro cytotoxicity test was also applied on the scaffold by using the extract method on the human dermal fibroblasts (HFFF2) cell line. The 3D-printed SA-Ps scaffolds are very useful structures for wound dressing applications.publishersversionpublishe

    THE EFFECT OF MASS LOSS ON MECHANIC PROPERTIES OF HEAT - TREATED PAULOWNIA WOOD

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    WOS: 000269071600010In this study, the effect of mass loss on mechanic properties of Paulownia (Paulownia elongata) wood was investigated. For this study, three different temperatures (160, 180, and 200 degrees C) and durations (3, 5, and 7 hours) were carried out. After heat treatment, the mass loss of the heat-treated samples were found and then it is determined how affected on mechanic properties of Paulownia wood The data obtained were analyzed using variance analysis, and then Tukey's test was used to determine the effect on mechanic properties of mass loss during heat treatment. The results show that mechanic properties were occurred decreasing in variation ration in relate with mass loss. While the maximum mass loss found was 9,78% at 200 degrees C and 7 hour, the compression strength, modulus of elasticity, bending strength and impact strength decreased about 17, 19, 78 and 88%, respectively. Hence, it is determined that the mass loss on mechanic properties of Paulownia wood significantly affected

    Risk Factors Predicting Upper Urinary Tract Deterioration in Patients With Spinal Cord Injury: A Retrospective Study

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    Aims: To determine the risk factors predicting upper urinary tract (UUT) deterioration in patients with spinal cord injury (SCI)
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