195 research outputs found

    Evaluating the Effect of Asymmetric Cross-section in Free Vibration and Bending Analysis Results of FG Sandwich Beam by Proposing Simple Efficient Element

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    In this paper, the asymmetric effect of the cross-section on the free vibration and bending analysis of FG sandwich beams are evaluated. For this purpose, a simple, efficient element is formulated. The new element is created based on the Timoshenko beam theory. The third- and second-order polynomials will be used for vertical displacement and rotation fields, respectively. The proposed formulation will be written based on satisfying the equilibrium equation. Satisfying the equilibrium equation of the Timoshenko beam, in addition to increasing element efficiency, will reduce the number of nodal unknowns. Several benchmark tests with different boundary conditions are used for thin and thick beams to prove the efficiency of the proposed element. The responses of the good elements of other researchers have been used for comparison. Numerical tests prove the rapid convergence rate and high accuracy of the proposed element in free vibration and bending analysis of the beams with various cross-section types and different boundary conditions. The pinned-sliding support conditions for the beam are used to evaluate the asymmetric effect of the cross-section. The use of asymmetric cross-sections creates additional axial displacements and intensifies the deflection of the beam under the lateral load. By increasing the asymmetry, the additional axial displacement and vertical displacement increase. These additional deflections for thin beams are more than thick ones. Also, asymmetry results in increasing the natural frequencies of beams. In the free vibration analysis, the effect of asymmetry on thick beams is more than thin ones

    Epidemiological study on sand flies in an endemic focus of cutaneous leishmaniasis, Bushehr city, southwestern Iran

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    Cutaneous leishmaniasis is the most important health problem in the city of Bushehr, southwestern Iran. The objective of the study was to determine some ecological aspects of sand flies in the city during 2010-2011. Sand flies were collected monthly from outdoors and indoors by sticky traps at four selected districts of the city. They were also dissected and examined by nested-PCR for identification of the parasite during August-September of 2011. A total of 1234 adult sand flies were collected and 6 species including 3 of Genus Phlebotomus and 3 of Genus Sergentomyia were identified. Four species including P. papatasi (3.98%), P. sergenti (1.14%), S. tiberiadis (87.18%), and S. baghdadis (7.7%) were found indoors. Six species including P. papatasi (3.47%), P. sergenti (3.17%), P. alexandri (0.1%), S. tiberiadis (77.74%), S. baghdadis (15.41%), and one female of S. clydei (0.11%) were collected from outdoors. Sand flies started to appear from March and disappear at the end of January. There was only one peak in the density curve in July. The study revealed that S. tiberiadis and S. baghdadis could enter indoors which 89 and 81.8% of them were found blood-fed, respectively. Moreover, P. papatasi, S. tiberiadis, and S. baghdadis were active indoors and outdoors in most months of the year. Nested-PCR of P. papatasi females was positive against kinetoplast DNA of L. major and L. turanica and also mixed natural infections were found by L. gerbilli and L. turanica. Moreover, mixed infections by L. major and L. turanica were observed in this species. Sergentomyia clydei and S. tiberiadis were found to be negative to any DNA of Leishmania species. Phlebotomus sergenti females were found infected with DNA of L. turanica and this is the first report of natural infection and detection of the parasite from this sand fly species in worldwide

    Deep Learning Based Signal Detection for OFDM VLC Systems

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    Differential Responses of Anopheles stephensi (Diptera: Culicidae) to Skin Emanations of a Man, a Cow, and a Guinea Pig in the Olfactometer

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    Background: Biting habit of mosquitoes plays an important role in the epidemiology of mosquito-borne diseases. Mosquitoes use a set of elaborate sensory modalities to find their preferred hosts by exploiting cues emanating from a nearby host. It has been suggested that the chemical profile of skin can provide further support for anthropophilic mosquito species to find their suitable hosts. This study aimed at revealing the value of skin emanation for a zoophilic species like Anopheles stephensi as a model. Methods: Skin emanations of a man, a cow and a Guinea pig were collected by ethanol soaked cottons. Upwind responses of mosquitoes to 100 and 200 mu l of filtered skin materials were non-competitively explored in a dual-choice olfactometer. L-lactic acid and other chemical content of the skin samples were identified by an enzymatic kit and GC-MS, respectively. Results: Unexpectedly, only human skin emanation was resulted in the statistically significant activation and attraction responses of An. stephensi in the wind tunnel. L-lactic acid content of this skin sample was 10 and 29 times more than the cow and the Guinea pig, respectively. The possible role of lactic acid and a few other identified compounds have been discussed here. Conclusion: Anopheles stephensi showed higher and more specific upwind responses to human skin emanation in the olfactometer. Undoubtedly, the thorough explanation of this unexpected finding needs further investigation. But, if new data verify this result, then, it may be necessary to reconsider the role of skin emanation and thence the human blood index and vectorial capacity of this zoophilic mosquito

    Recent advances on biocompatible and biodegradable nanoparticles as gene carriers

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    Introduction: Gene therapy mainly depends on the use of appropriate delivery vehicles with no induction of immune responses and toxicity. The limitations of viral gene carriers such as induction of immunogenicity, random integration in the genome of the host, limitations in the size, has led to a movement toward non-viral systems with much safer properties. Biodegradable and biocompatible polymeric nanocarriers due to several unique properties such as excellent biocompatibility, prolonged gene circulation time, prevented gene degradation, passive targeting by using the enhanced permeability and retention (EPR) effect, and possibility of modulating polymers structure to obtain desirable therapeutic efficacy, are among the most promising systems for gene delivery. However, biodegradable gene delivery systems have some limitations such as inadequate stability and slow release of therapeutics which have to be overcome. Thus, a variety of advanced functional biodegradable delivery systems with more efficient gene delivery activity has recently been introduced. Areas covered: This review summarizes different aspects of biodegradable and biocompatible nano carriers including formulation, mechanism of intracellular uptake, various potential applications of biodegradable nanoparticles and finally recent studies on the therapeutic efficacy of these nanoparticles in sustained delivery of genes

    Assessment of expression of interferon γ (IFN-G) gene and its antisense (IFNG-AS1) in breast cancer

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    Background The role of long non-coding RNAs has been extensively appreciated in the contexts of cancer. Interferon γ-antisense RNA1 (IFNG-AS1) is an lncRNA located near to IFN-γ-encoding (IFNG) gene and regulates expression of IFNG in Th1 cells. Methods In the present study, we evaluated expression of IFNG and IFNG-AS1 in 108 breast samples including tumoral tissues and their adjacent non-cancerous tissues (ANCTs) using real-time PCR. IFNG-AS1 was significantly upregulated in tumoral tissues compared with ANCTs (expression ratio = 2.23, P = 0.03). Results Although the expression of IFNG was higher in tumoral tissues compared with ANCTs (relative expression = 1.89), it did not reach the level of significance (P = 0.07). IFNG expression was significantly higher in HER2-negative tumoral tissues compared with HER2-positive ones (P = 0.01) and in grade 1 samples compared with grade 2 ones (P = 0.03). No other significant difference was found in expressions of genes between other groups. Conclusion Significant strong correlations were detected between expression of IFNG and IFNG-AS1 in both tumoral tissues and ANCTs. The present study provides evidences for participation of IFNG and IFNG-AS1 in the pathogenesis of breast cancer and warrants future studies to elaborate the underlying mechanism

    Fabrication of an olfactometer for mosquito behavioural studies

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    Background & objectives: Olfaction is the major sensory modality involved in the resource searching behaviour of insects including vector mosquitoes (Diptera: Culicidae). To date, our current country-wide knowledge on the host-seeking behaviour of Iranian mosquitoes is mainly confined to host preference which has exclusively come from field studies. Olfactometer is a scientific tool by which more naive aspects of man-vector contact can be clarified under controlled and less biased conditions. Methods: The wind tunnel and stimulus delivery system was constructed from acrylic materials based on previously introduced models with some modifications. Air supply and required light were ensured by a powerful compressor and incandescent bulbs, respectively. Desired level of temperature was maintained by controllable heating radiators. For humidity production a unique in-built piezo system was devised in the course of the air flow. Fine regulators facilitated the continuous generatation of the humidity at a preset level. Results: Titanium tetrachloride smoke plus monitoring of the wind speed revealed that the flow of air was proper and invariable. A desired level of humidity and temperature could be set up in just 10 and 15-45 min, respectively. These physical parameters varied only +/-2% (humidity) and +/-0.15 degrees C (temperature) in a typical 20 min duration. Conclusion: The first sophisticated olfactometer in the field of medical entomology in Iran is reported here. Fast set up and stability of physical parameters are its salient features. It is expected that with the aid of this olfactometer further information on the physiological principles of the host-seeking behaviour of mosquitoes become available soon

    A New Technique in saving Fingerprint with low volume by using Chaos Game and Fractal Theory

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    Fingerprint is one of the simplest and most reliable biometric features of human for identification. In this study by using fractal theory and by the assistance of Chaos Game a new fractal is made from fingerprint. While making the new fractal by using Chaos Game mechanism some parameters, which can be used in identification process, can be deciphered. For this purpose, a fractal is made for each fingerprint, we save 10 parameters for every fingerprint, which have necessary information for identity, as said before. So we save 10 decimal parameters with 0.02 accuracy instead of saving the picture of a fingerprint or some parts of it. Now we improve the great volume of fingerprint pictures by using this model which employs fractal for knowing the personality

    Effect of Ketofol instead of Propofol on hemodynamic stabilization for induction of Anesthesia in Laparatomy

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    Introduction: Hemodynamic alterations are a common complication during anesthetic induction with intravenous anesthesia. Hypotension due to propofol injection may be very severe in cardiac vascular patient. Ketamine produces the significant increasing but temporary in systematic blood stream, heartbeat, cardiac output through central sympathetic stimulation.Objective: To determine effect of ketofol and propofol for induction of anesthesia on hemodynamic changes during induction of anesthesiaMethods: In a randomized cinical trial study 96 patient who were candidate for laparotomy enrolled and divided into two random group of propofol (48 person) and ketofol (48 person). Hemodynamic changes were recorded and examined after induction, after intubation and 5 and 10 minutes after intubation.Results: Heart rate was significantly variable in propofol group compare to ketofol group. Systolic, Diastolic, and mean arterial blood pressure was not significantly changed during time period of recording in ketofol group. However, blood pressure was significantly changed during the study in propofol group.Conclusion: ketofol is a proper alternative to propofol to stabilize heart rate and blood pressure in laparatomy
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