41 research outputs found
Physical and Electrical Properties of Trimetallic Nitride Template Endohedral Metallofullerenes and their Polymer Nanocomposites
The main objective of this study was characterization of pure metallic nitride fullerene, MNF, and MNF containing polymers to evaluate these materials as suitable devices for tunable applications. Polymer-fullerene nanocomposites consisting of linear polyurethane (PU) segments crosslinked via polyhydroxylated fullerenes (C60 and Sc3N@C80, a metallic nitride fullerene) were prepared and characterized for their mechanical and dielectric properties using dynamic mechanical analysis (DMA) and broadband dielectric spectroscopic techniques. Polyhydroxylated fullerenes C60(OH)29 and Sc3N@C80(OH)18 were synthesized in a high yield through a solid-state high sheer ball-milling procedure and were characterized using a verity of techniques, such as FT-R, mass spectroscopy (MS) and thermal gravimetric analysis (TGA), to elucidate their structures. A difunctional isocyanate-terminated prepolymer was prepared from the reaction of poly(tetramethylene oxide) glycol (PTMO, ∼2000 g/mol) and methylene bis(4-isocyanatobenzene) (MDI) followed by the addition of the crosslinking fullerene agent. Fullerene-polymer networks [C60-PU and Sc3N@C80-PU] having high gel fractions and good mechanical properties and thermal stabilities were produced. Dynamic mechanical analyses of (C60 or Sc3N@C80)-PU networks indicated a glass transition temperature, Tg, of -50°C with a sub-Tg relaxation due to local chain motions. Broadband dielectric spectroscopic analyses of the nanoparticles prior to incorporation into the networks revealed one relaxation and large ϵ\u27 values in hydroxylated C60 relative to unfunctionalized C60. The analogous hydroxylated Sc3N@C80 exhibited two relaxations, and the extra relaxation may be due to reorientations of cage-encapsulated Sc3N clusters. Permittivity values (ϵ\u27) for Sc3N@C80-PU were found to be higher than the corresponding values for C60-PU, likely because of the rotationally mobile dipoles. For temperature \u3c 0°C there was a dielectric loss peak due to the glass transition of the PU matrix and another at a lower temperature due to short range chain motions. The loss-frequency spectra of all prepared samples were analyzed sing the Kramers-Kronig transformation and Havriliak-Negami (HN) equation to extract information about relaxation processes taken place in these samples. Capacitance-voltage characteristics of the fullerene-PUs did not show any significant change with the applied dc bias voltage in the range of our instrument window (-30 to +30 volt). A general conclusion is that this class of materials can be rendered quite polarizable
Speeded Up Robust Features Descriptor for Iris Recognition Systems
اكتسبت النظم البايومترية اهتماما كبيرا لعدة تطبيقات. كان تحديد القزحية أحد أكثر التقنيات البايومترية تطوراً للمصادقة الفعالة. نظام التعرف على القزحية الحالية يقدم نتائج دقيقة وموثوق بها على أساس الصور المأخوذة بالأشعة التحت الحمراء (NIR) عندما يتم التقاط الصور في مسافة ثابتة مع تعاون المستخدم. ولكن بالنسبة لصور العين الملونة التي تم الحصول عليها تحت الطول الموجي المرئي (VW) دون التعاون بين المستخدمين، فإن كفاءة التعرف على القزحية تتأثر بسبب الضوضاء مثل صور عدم وضوح العين، و تداخل الرموش ، والانسداد بالأجفان وغيرها. يهدف هذا العمل إلى استخدام (SURF) لاسترداد خصائص القزحية في كل من صور قزحية NIR والطيف المرئي. يتم استخدام هذا النهج وتقييمه على قواعد بيانات CASIA v1and IITD v1 كصورة قزحية NIR وUBIRIS v1 كصورة ملونة. وأظهرت النتائج معدل دقة عالية (98.1 ٪) على CASIA v1, (98.2) على IITD v1 و (83٪) على UBIRIS v1 تقييمها بالمقارنة مع الأساليب الأخرى.Biometric systems have gained significant attention for several applications. Iris identification was one of the most sophisticated biometrical techniques for effective and confident authentication. Current iris identification system offers accurate and reliable results based on near- infra -red light (NIR) images when images are taken in a restricted area with fixed-distance user cooperation. However, for the color eye images obtained under visible wavelength (VW) without cooperation between the users, the efficiency of iris recognition degrades because of noise such as eye blurring images, eye lashing, occlusion and reflection. This works aims to use Speeded up robust features Descriptor (SURF) to retrieve the iris's characteristics in both NIR iris images and visible spectrum. This approach is used and evaluated on the CASIA v1and IITD v1 databases as NIR iris image and UBIRIS v1 as color image. The evaluation results showed a high accuracy rate 98.1 % on CASIA v1, 98.2 on IITD v1 and 83% on UBIRIS v1 evaluated by comparing to the other method
Cerebrovascular Stroke Recurrence among Critically Ill Patients at a Selected University Hospital in Egypt
Cerebrovascular stroke (CVS) is a fatal disease. Literature review cited that, CVS recurrence is more devastating than the first attack. The risk of recurrent CVS is up to 15 times greater than the risk of CVS and is attributed to insufficient control of risk factors and non compliance with medical advice. So that, identification of risk factors of recurrence is an important role of the critical care nurses, plays an essential role in the prevention of further stroke. Aim: to study the risk factors, frequency and severity of recurrent cerebrovascular stroke among adult critically ill patients admitted to intensive care units. Research questions: Q1- What are the risk factors of recurrent cerebrovascular stroke among critically ill patients at a selected university hospital? Q2- What are the intervals of recurrence from the first attack of cerebrovascular stroke? Q3- What is the frequency of recurrent cerebrovascular stroke attacks among critically ill patients? Q4-What is the severity rate of recurrent cerebrovascular stroke among critically ill patients?. A descriptive exploratory research design was utilized in the current study. The study was conducted at different CVS intensive care units at a selected University Hospital. A sample of convenience including all adult patients admitted to the ICU with recurrent CVS over a period of six months (80 patients) was included. Three tools were used for data collection: socio-demographic and medical data sheet, CVS risks factors assessment sheet, and the National Institutes of Health Stroke Scale (NIHSS). Results: The majority of the studied group admitted with the first recurrence of CVS, had different chronic illnesses such as hypertension (100%) & diabetes mellitus (95%). The duration of CVS recurrence ranged from two - < five years among 30% of the studied group. 36.25% of the studied group admitted with severe degree of CVS with a mean severity score of (X = 19.17 + SD = 1.255). Conclusions: uncontrollable risk factors (old age, male gender, marriage); life style risk factors (smoking, obesity, low income); chronic medical diseases (old CVS, hypertension, diabetes mellitus, ischemic heart disease, myocardial infarction, heart failure,… etc ); noncompliance with prescribed drugs of chronic illnesses, abnormal laboratory investigations (high cholesterol, triglyceride, low density lipoprotein) represented the common risk factors and contributed to recurrent cerebrovascular stroke with different severity. Key words: Cerebrovascular stroke, recurrence, critically ill patients, risk factors, severity
Intensive Care Nurses’ Knowledge & Practices regarding Infection Control Standard Precautions at a Selected Egyptian Cancer Hospital
Critical care nurses are the health care professionals who have the obligation to protect critically ill patients against infection especially those who are immune compromised, in order to enhance their recovery, prevent deterioration in their health, and achieve high quality nursing care. Therefore critical care nurses should have sound knowledge and strict adherence to infection control standard precautions. Aim of the study: to assess nurses' knowledge and evaluate their practice regarding infection control standard precautions. Research design: A descriptive research design was utilized in this study. Sample: A sample of convenience including 77 ICU nurses was recruited in the current study. Setting: The study was carried out at the Intensive Care of a selected Cancer Hospital in Egypt. Tools of data collection: Two tools were developed, tested for clarity and feasibility, and then used to collect data pertinent to the current: a- Structured Interview Questionnaire to assess nurses' knowledge regarding infection control standard precautions. b-Nurses’ Performance Observational Checklist to evaluate nurses' practice / utilization of infection control standard precautions. Results: the current study revealed that, approximately two thirds (63.6%) of the studied sample had unsatisfactory knowledge level (<75%) with a mean total knowledge score of 102.5 + 13.7. However, more than half (57.1%) of the studied sample had satisfactory performance level (>75%) with a mean total performance scores of 77.3+4.4. Negative significant correlations were found between: mean knowledge scores, and age; mean knowledge scores and years of experience (r = -.323 & r = -.325 at P < 0.004 respectively); between mean practice scores and age; and mean practice scores and years of experience (r = -.235 & r =-.291 at P < 0.39, 0.010 respectively). However, positive correlations were found between mean knowledge scores and mean practice scores; age and years of experience (r = 0.318 & 0.794 at P < 0.005 & 0.000 respectively). Conclusion: Based on findings of the current study, it can be concluded that inspite of having satisfactory performance level regarding infection control standard precautions, critical care nurses had unsatisfactory knowledge level. Recommendation: updating knowledge and performance of ICU nurses through continuing in-service educational programs; emphasizing the importance of following the latest evidence-based practices of infection control in continuing education / training programs; strict observation of nurses’ performance/ utilization of infection control standard precautions and correction of poor practices by the infection control team are required; and providing training programs for newly joined ICU nurses about infection control standard precautions and at regular intervals. Key Words: Infection control (IC), Standard precautions (SP), Intensive care unit (ICU), Knowledge, Practice
Five Bivalve Species from the Recently Discovered Coral Reef in the Marine Coastal Waters of Iraq
In the present report five bivalve species are newly recorded from the recently discovered coral reef in the coastal waters of Iraq, North West Arabian Gulf. The bivalves were inhabit a hard coral substratum as well as sand and mud substrata, at depth ranging from 7-10 m. The region is characterized by high temperature subtropical climate (temperature range: 14-34 C˚). The identified mulluscan bivalves namely Chlamys livida, Pinna bicolor, Malvifundus normalis, Barbatia decussate, and Lithophaga robusta. All the present specimens bivalves were living animals and they classified according to morphological characteristics. Specimens were deposited at the Genetic Legacy Laboratory and Museum of the Marine Science Center/ University of Basrah
Circulating dendritic cells in pediatric patients with nephrotic syndrome
Background: Dendritic cells (DCs) represent one of the most extensively studied topics in immunology, because of their central role in the induction and regulation of adaptive immunity, and because of their therapeutic potential for manipulating immune responses. Objectives: To evaluate circulating DC levels in pediatric patients with idiopathic nephrotic syndrome (NS) and its relation to disease activity in these patients. Methods: Fifteen nephrotic patients in relapse (proteinuria>40mg/m2/hour, hypoalbuminemia, and edema) before initiating steroid therapy (Group I), and another15 nephrotic patients in remission after withdrawal of steroid therapy (Group II) were compared to 15 age- and sex- matched healthy children. Besides clinical evaluation and routine laboratory investigations of nephrotic syndrome, circulating DCs were measured by flowcytometry. Results: Circulating DC count was lower in nephrotic patients in both proteinuria and remission groups [(48.89±13.52) and (64.64±7.69) X106/liter respectively] than in the control group (78.54±9.8) X106/liter with highly significant statistical difference (p < 0.001), and lower in proteinuria group than the remission group with highly significant statistical difference (p < 0.001). There was a positive correlation between DC count and serum albumin (moderate association) (p=0.002) and a negative correlation between DC count and urine protein /creatinine ratio (strong association) (p=0.001). Conclusion: Nephrotic syndrome was associated with decreased number of circulating DCs and the decrease was more apparent in patients with active disease. The positive correlation between DC counts and total protein, and serum albumin, and the negative correlation between DC count and urine protein/creatinine ratio point to the link between the decrease in DC count and the severity of the disease process.Keywords: Denderitic cells, nephrotic syndrome, immune deficiencyEgypt J Pediatr Allergy Immunol 2011;9(1):41-4
Effect of dexamethasone on reducing pain and gastrointestinal symptoms associated with cesarean section: a systematic review and meta-analysis
Background: Dexamethasone has analgesic and antiemetic actions that have been documented in the literature. Therefore, we performed a systematic review and meta-analysis to investigate its overall effectiveness in reducing a variety of negative outcomes after cesarean section.
Objectives: To investigate the efficacy and safety of dexamethasone for reducing pain associated with cesarean section, nausea, vomiting, pruritus, postoperative need for analgesia, postoperative antiemetic requests and headache.
Methods: We searched PubMed, Cochrane CENTRAL, SCOPUS, and Web of Science for relevant clinical trials. We then performed a systematic review and meta-analysis, including only randomized, placebo-controlled clinical trials. Our main population target was women undergoing elective cesarean delivery. The intervention under consideration was dexamethasone administered both by intravenous (IV) or subcutaneous (SC) over a variety of doses. The comparator was a placebo. Our main outcomes included: (1) perceptions as indicated by pain scores, (2) occurrence of nausea and (3) occurrence of vomiting. Secondary outcomes included: (4) occurrence of pruritus, (5) need for postoperative analgesia, (6) need for postoperative antiemetic drugs and (7) occurrence of headache. We assessed the quality of included studies using the risk of bias tool described in Cochrane\u27s handbook for systematic reviews of interventions.
Results: We found that dexamethasone seemed to significantly reduce scores for pain at rest (p<0.001), as well as occurrence of nausea (p<0.001) and vomiting (p<0.001). The drug also showed significant reduction of negative symptoms in other secondary outcomes, including need for postoperative analgesia (p<0.001) and postoperative antiemetic drugs (p<0.001). However, the drug showed no significant effect in reducing headache and pruritus or in improving pain at movement scores.
Conclusion: Dexamethasone appears to decrease perception of pain at rest and protects against nausea and vomiting. However, it does not seem effective against headaches or pruritus
A SURVEY OF CLOUD BASED SECURED WEB APPLICATION
ABSTRACT Cloud computing is a schema for allowingappropriate onrequest network access to a shared pool of configurable computing resources, that can be rapidlydelivered and released by minimal management effort or service provider.In cloud computing, you need a Web browser to access to everything needed to run your business from the required applications, services, and infrastructure. Many web developers are not security-aware. As a result, there exist many web sites on the Internet that are vulnerable. More and more Web-based enterprise applications deal with sensitive financial and medical data, which, if compromised, in addition to downtime can mean millions of dollars in damages. It is crucial to protect these applications from malicious attacks. In this paper we present a comprehensive survey of cloud based secure web application in the literature.The goal of this paper is to present a comparison of various previous methods proposed in the literature and a comparison between Python to other used programming languages
Preparation and Preliminary Dielectric Characterization of Structured C\u3csub\u3e60\u3c/sub\u3e-Thiol-Ene Polymer Nanocomposites Assembled Using the Thiol-Ene Click Reaction
Fullerene-containing materials have the ability to store and release electrical energy. Therefore, fullerenes may ultimately find use in high-voltage equipment devices or as super capacitors for high electric energy storage due to this ease of manipulating their excellent dielectric properties and their high volume resistivity. A series of structured fullerene (C60) polymer nanocomposites were assembled using the thiol-ene click reaction, between alkyl thiols and allyl functionalized C60 derivatives. The resulting high-density C60-urethane-thiol-ene (C60-Thiol-Ene) networks possessed excellent mechanical properties. These novel networks were characterized using standard techniques, including infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermal gravimetric analysis (TGA). The dielectric spectra for the prepared samples were determined over a broad frequency range at room temperature using a broadband dielectric spectrometer and a semiconductor characterization system. The changes in thermo-mechanical and electrical properties of these novel fullerene-thiol-ene composite films were measured as a function of the C60 content, and samples characterized by high dielectric permittivity and low dielectric loss were produced. In this process, variations in chemical composition of the networks were correlated to performance characteristics
Detection of Extraintestinal Pathogenic Escherichia coli among Normal Stool Flora of Young, Healthy, Unmarried Males & Females as Predisposing Factor to Extraintestinal Infections:A Comparison Study
In this study we surveyed the dominant normal stool flora of randomly selected healthy, young (18-23 years old), unmarried (doctrinal) Iraqi college students (males and females) for the carriage of extraintestinal pathogenic E. coli (ExPEC). ExPEC virulence was detected phenotypically by mannose resistant hemagglutination of human red blood cells (MRHA) and mannose sensitive (MS) agglutination of Bakers' yeast (Saccharomyces cerevisceae). From 88 college students, 264 E. coli isolates were obtained (3 isolates per person): 123 from 41 females and 141 from 47 males. Of these isolates, 56% (149/264) caused MS agglutination of yeast cells and 4.16% (11/264) showed MRHA. Eighty two percent (9/11) of the isolates with MRHA also caused MS agglutination of yeast cells. Statistically the difference is not significant (P < 0.05) among males and females regarding the MS agglutination of yeast cells: 59% (72/123) of females' isolates vs. 55% (77/141) of males' isolates. Conversely, the difference is clear regarding the carriage of isolates with MRHA. All the isolates with MRHA were distributed among females' dominant stool flora (11/123: 8.94%) whereas none of the males' dominant stool flora showed MRHA (0/141: 0%). Five females out of 41 (12.19%) had isolates with MRHA. All the three isolates in 2 of these 5 females showed MRHA, 2 isolates in another 2 showed MRHA, and only one isolate in 1 female caused MRHA. Therefore we can say that the difference among males and females in fecal carriage of E. coli ,with characteristics of ExPEC, can be a predisposing factor of females to ExPEC infections more than males