176 research outputs found
ASSESSING ONLINE REGISTRATION SYSTEM’S (ORS) SUCCESS: AN APPLICATION OF DELONE AND MCLEAN’S MODEL OF INFORMATION SYSTEMS SUCCESS
The study applied DeLone and McLean’s IS success model in the mandatory context of online registration system (ORS) in one Jordanian university. Six dimensions were used to asses ORS success from the perspective of system users, i.e. students (information quality, system quality, service quality, user satisfaction, net benefits and intention to use). Consistent with DeLone and McLean’s suggestion, the study focused on the “intention to use”, rather than “use”, dimension to accommodate the mandatory nature of ORS. Quantitative data was collected, through a questionnaire instrument, from a sample of 1360 undergraduate students studying in different faculties at the university. Statistical analysis of the study’s model was conducted using “SmartPLS” software, version 2.0.M3. Empirical analysis has underlined the multidimensional and interdependent nature of ORS success. Furthermore, empirical examination of the model’s hypotheses has indicated that students’ “intention to use” ORS is dependent on system quality, service quality, user satisfaction and net benefits
Comparative Study of In Situ Loaded Antibody and PEG‐Fab NIPAAM Gels
Hydrogels can potentially prolong the release of a therapeutic protein, especially to treat blinding conditions. One challenge is to ensure that the protein and hydrogel are intimately mixed by better protein entanglement within the hydrogel. N-isopropylacrylamide (NIPAAM) gels are optimized with poly(ethylene glycol) diacrylate (PEDGA) crosslinker in the presence of either bevacizumab or PEG conjugated ranibizumab (PEG10-Fabrani). The release profiles of the hydrogels are evaluated using an outflow model of the eye, which is previously validated for human clearance of proteins. Release kinetics of in situ loaded bevacizumab-NIPAAM gels displays a prolonged bimodal release profile in phosphate buffered saline compared to bevacizumab loaded into a preformed NIPAAM gel. Bevacizumab release in simulated vitreous from in situ loaded gels is similar to bevacizumab control indicating that diffusion through the vitreous rather than from the gel is rate limiting. Ranibizumab is site-specifically PEGylated by disulfide rebridging conjugation. Prolonged and continuous release is observed with the in situ loaded PEG10-Fabrani-NIPAAM gels compared to PEG10-Fabrani injection (control). Compared to an unmodified protein, there is better mixing due to PEG entanglement and compatibility of PEG10-Fabrani within the NIPAAM-PEDGA hydrogel. These encouraging results suggest that the extended release of PEGylated proteins in the vitreous can be achieved using injectable hydrogels
Physicochemical characterization of natural hydroxyapatite/ cellulose composite
The natural hydroxyapatite (HAp, activated at different temperatures)/ cellulose composites have been prepared by usingsonication method to improve the physical properties of the cellulose fibre. The molecular level interaction and the physicalproperties of the hydroxyapatite/cellulose composite are examined using FTIR, X-ray diffraction, SEM, and thermalanalysis. The absorption bands at around 660 cm1 confirm the O–P–O bending vibration in the HAp/cellulose composites.There is a difference in the d-spacing of the HAp /cellulose composite, indicating that the HAp is reactive towards cellulose.SEM indicates that HAp could penetrate the cellulose network structure to form particles that is helpful to improve themechanical properties of the cellulose. The porosities of HAp/cellulose composites decrease, and their compressive strengthincrease as compared to those of cellulose. Thermogravimetric analysis confirms the highest thermal stability of theprepared composites
High plasma levels of adrenomedullin in collagen diseases
Background: Adrenomedullin (ADM), a potent vasorelaxant/hypotensive peptide, was shown recently to be over-expressed in inflammatory rheumatic diseases. Objectives: The aim of this study was to investigate the value of ADM as a laboratory marker of disease activity in juvenile rheumatoid arthritis (JRA) and pediatric onset- systemic lupus erythematosus (SLE) and its relation to other markers of disease activity such as clinical scores, the ESR and tumor necrosis factor-α (TNF-α). Methods: The study included 24 patients with JRA, 17 with childhood onset- SLE, as well as, 19 with rheumatic arthritis and twenty clinically healthy age- and sex- matched subjects. Clinical evaluation for disease activity was performed using the clinical activity score index in JRA, and SLE-DAI in SLE. Subjects were investigated to verify the diagnosis and disease activity. Plasma ADM and serum of TNF-α levels were then assayed. Results: Serum TNF-α and plasma ADM levels were significantly higher in JRA and SLE patients than in rheumatic arthritis patients and healthy controls. Though serum TNF-α and plasma ADM levels were both higher in JRA (73.88 ± 11.6 pg/ml and 156.5 ± 22.4 pg/ml, respectively) compared to SLE (48.82 ± 7.5 pg/ml and 85.12 ± 15.7 pg/ml, respectively), the difference was of statistical significance only in ADM. Both serum TNF-α and plasma ADM levels were significantly higher in systemic onset-JRA (139.75 ± 18.5 and 260.25 &#177 28.6 pg/ml, respectively) compared to the pauciarticular-onset type (33.8 ± 3.04 and 93.4 ± 9.35 pg/ml, respectively), but comparable to the polyarticular onset cases (69.97 ± 8.45 and 149.87 ± 21.15 pg/ml, respectively). Positive correlations were noticed between plasma ADM and activity score index (r=0.72), ESR (r=0.59) and serum TNF-α (r=0.64) in JRA. The serum TNF- α was not influenced by the site of lupus activity unlike plasma ADM that was higher in subjects suffering from lupus arthritis or cardiovascular manifestations. The afore-mentioned markers correlated positively to the ESR in SLE but not to the SLE-DAI. With a cut-off value of TNF-α = 31 pg/ml and that for ADM = 80 pg/ml calculated from the results of the included rheumatic arthritis patients, ADM appeared to be a more sensitive marker of activity in JRA and SLE compared to TNF-α. Conclusion: Plasma ADM was over-expressed in JRA and SLE. It correlated with the clinical and biochemical activity markers in JRA suggesting that it can be used as an indicator of disease activity. In SLE, ADM levels correlated with ESR and TNF- α levels and it could be of value in identifying patients with arthritis and cardiac involvement.<br.Keywords: Adrenomedullin, JRA, SLE, TNF-α, arthritisEgypt J Pediatr Allergy Immunol 2004; 2(1): 28-3
Monocyte chemotactic protein-4 (MCP-4/CCL-13) and CC chemokine receptor 3 (CCR3) in the sputum of asthmatic children
Background: Monocyte chemotactic protein-4 (MCP-4/CCL-13) is a potent chemoattractant to eosinophils, monocytes and lymphocytes. Objective: We aimed to investigate MCP-4 and its CC chemokine receptor 3 (CCR3) expression on cells of induced sputum during acute asthma exacerbation. Methods: Immunohistochemistry was used to assess MCP-4 and CCR3 expression on induced sputum cells of 30 children during asthma exacerbation and 20 healthy matched controls. Patients were divided into three groups according to exacerbation severity; mild, moderate and severe (n = 10 for each). Patients were followed until quiescence, when sputum was re-examined. Results: MCP-4 and CCR3 were expressed on eosinophils and monocytes. Lymphocytes expressed only MCP-4. The percentages of sputum total cells, eosinophils and lymphocytes expressing MCP-4 and/or CCR3 were significantly higher during asthma exacerbation than in controls and negatively correlated with peak expiratory flow rate, whereas that of monocytes was not. The percentages of sputum total cells, eosinophils, monocytes and lymphocytes expressing MCP-4; and total cells and eosinophils expressing CCR3 were significantly higher in patients with severe than those with mild and moderate exacerbations. When patients were followed till remission, the percentages of sputum cells expressing MCP-4 and CCR3 decreased. Sputum eosinophil percentage correlated positively with the percentage of eosinophils expressing MCP-4 and CCR3 (r = 0.69, p < 0.0001; r = 0.62, p < 0.001, respectively). The percentage of sputum eosinophils expressing MCP-4 correlated positively with that of cells expressing CCR3 (r = 0.95, p < 0.0001). Conclusion: The expression of MCP-4 and CCR3 on sputum cells increases during acute asthma exacerbation and this increase correlates with exacerbation severity, and it decreases during remission. Modification of their expression could be a potential target for asthma therapy.Keywords: asthma, CCL-13; CCR3; chemokines; eosinophils; MCP-4; sputumEgypt J Pediatr Allergy Immunol 2008; 6(1): 13-2
Improving the accuracy of the active power load sharing in paralleled generators in the presence of drive motors shaft speed instability
Improving the accuracy of the active power load sharing in paralleled generators in the presence of drive motors shaft speed instability / Abdullah M. Eial Awwad, Mahmoud M. S. Al-Suod, Alaa M. Al-Quteimat, O. O. Ushkarenko, Atia AlHawamleh // International Journal of Electronics and Telecommunications. – 2021. – Vol. 67. – P. 371–377.The paper suggests an improved method of active power distribution among the gas-diesel generators operating in parallel; the method involves the control of torque and the angular positions of their rotors. The use of the suggested approach to the solution of the active power distribution task in the presence of instability of drive motor speed provides the increase of autonomous power system operation efficacy and rising the power unit’s performance. The authors analyzed the causes of generation of low-frequency fluctuations of generator drive engine speed; in autonomous electric power systems, gas diesel generators are increasingly used as such generator drive engines. It is suggested to use the developed method and structure of the optical device for control of rotation period and the measurement of the generator rotor angle position characterized with high accuracy, as the sensor. The authors developed a schematic diagram of active power distribution among the generators operating in parallel, which uses the cross feedback for gas-powered diesel engine shafts momentum and the generator rotor angle position. They obtained experimental results confirming the efficiency of the suggested active power distribution method and its practical implementation
Bioactivities of holmium(III) and gadolinium(III) complexes of thymoquinone
Chemotherapeutic agents which are the main stay in cancer treatment are toxic with numerous contrary side effects. A number of chemical, physical, and computational techniques were applied to synthesize and elucidate the structural and functional characterization of the new designed bioligands and their metal complexes. Besides, several biological techniques for developing therapeutics and diagnostics agents of these new designed materials were used. The trivalent holmium(III) and gadolinium(III) metal complexes of thymoquinone (TQ) were synthesized. Toxicities and other bioactivites were undertaken with existing drug combinations and more effective tumor models will be established. The molecular structures of TQ-metal complexes were elucidated based on particular spectral approaches. The NF-kB (nuclear factor kappa-light-chain enhancer of activated B Cells) luciferase, elastase release, superoxide anion (O2•−) generation, and DPPH (1,1-diphenyl-2-picryl hydrazyl) free-radical scavenging activities of TQ and its synthesized complexes were elucidated and discussed. The core research is to use coordination and organometallic chemistry to design new bioligands and binary, ternary, mixed ligand, multi metal multi ligand complexes pursing a bio target continuously with structure-activity relationships (SARS).
KEY WORDS: Thymoquinone, Holmium, Gadolinium, Bioactivities
Bull. Chem. Soc. Ethiop. 2021, 35(1), 87-96.
DOI: https://dx.doi.org/10.4314/bcse.v35i1.
Marginal and Internal Crown Fit Evaluation of CAD/CAM versus Press-Laboratory Lithium Disilicate Crown
This study aims to evaluate the marginal gap and internal adaptation of lithium disilicate crowns fabricated by conventional press-dental laboratory and CAD/CAM systems. The size of the marginal and internal gaps of crowns is fabricated with the two techniques in the current study; the research will be performed in an effort to improve clinical outcomes. Tooth #14 was prepared per standard specification to receive the lithium disilicate crowns. Sixty Type IV gypsum dies tooth #14 were duplicated and divided into three groups (n=30). The lithium disilicate CAD/CAM system (Group 1) was fabricated with the E4D CAD/CAM system according to manufacturer's instructions. For press-dental laboratory made crowns, impressions were taken on the region area with two-step impression techniques with light and putty consistency VPS. Impressions were sent to two independent dental laboratories (Groups 2 and 3) for fabricating the monolithic press lithium disilicate crown. Tooth #14 was optically scanned and lithium disilicate blocks were used to fabricate crowns using CAD/CAM technique. Polyvinyl siloxane impressions of the prepared teeth were made and monolithic pressed lithium disilicate crowns were fabricated. The marginal gap was measured using optical microscope at 160× magnification (Keyence VHX-5000, Japan) and internal fit of the crowns was assessed by the silicone replica technique. Four sections of each replica were obtained, and each section was evaluated at four points: marginal gap (MG), axial wall (AW), axio-occlusal edge (AO) and Centro-occlusal wall (CO), using an image analyzing software. Statistical analysis was performed using ANOVA and chi-squared test. Study design: Experimental. Setting of study: University of Palestine and Laser Specialized center For Esthetic Dentistry
Consumer Adoption of Self-Service Technologies in the Context of the Jordanian Banking Industry: Examining the Moderating Role of Channel Types
YesThis study aimed to examine the key factors predicting Jordanian consumers’ intentions and
usage of three types of self-service banking technologies. This study also sought to test if the
impacts of these main predictors could be moderated by channel type. This study proposed a
conceptual model by integrating factors from the unified theory of acceptance and use of
technology (UTAUT), along with perceived risk. The required data were collected from a
convenience sample of Jordanian banking customers using a survey questionnaire. The
statistical results strongly support the significant influence of performance expectancy, social
influence, and perceived risk on customer intentions for the three types of SSTs examined. The
results of the X2 differences test also indicate that there are significant differences in the
influence of the main predictors due to the moderating effect of channel type. One of the key
contributions of this study is that three types of SSTs were tested in a single study, which had
not been done before, leading to the identification of the factors common to all three types, as
well as the salient factors unique to each type
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