497 research outputs found
Fault Diagnosis Method for Mobile Ad-hoc Network by Using Smart Neural Networks
AbstractMANETs are dynamic collection of autonomous nodes that communicate with each other via wireless connections. One of the events that the network should have expected it to be a fault, and the behavior is more important, in this network. So that fault diagnosis can effect on final performance of the network in such a way that it does not fall under the negative impact of the fault. A non-linear neural network is a statistical method for modeling data or the tools to make decisions. Artificial neural network is a method for pattern recognition and classification. Error detection is a problem of categorization or classification. The use of neural networks can be useful in fault diagnosis in MANETs because of fault diagnosis is a classification problem. But one problem with this method is placed in a local optimum. Here a method based on the combination of the back-propagation algorithm, a local search algorithm and learning automata as efficient global search, is proposed. In the proposed method, the algorithm of learning automata adjusting learning rate on neural network according to given formula. For training and testing the neural network of the mobile network parameters that were measured, were used as input and output. The results show that the proposed method in terms of repeatability, reliability and lack of placement in a local optimum is better
Availability Analysis of Predictive Hybrid M-Out-of-N Systems
In m-out-of-n system, if m-out-of-n modules agree, system can report consensus; otherwise, the system fails. On the other hand, in predictive hybrid system if there is no agreement, a history record of previous successful result(s) is used to predict the output. In order to analyze the availability of predictive hybrid redundancy system, Markov modeling is utilized. By using Markov model of the system in steady state, the availability is derived and compared with m-out-of-n system. The results of simulation demonstrated that the availability of predictive hybrid system is higher than m-out-of-n system especially for large m
Comparative Study of Growth Patterns for Three Strains of Broiler Chickens Using Mathematical Models
The aim of the current study was to investigate the growth pattern of three genetic strains of broiler chickens including Ross 308, Cobb and Arbor Acres by mathematical models. For this purpose, the body weight of 500 broilers for each strain was recorded weekly. Gompertz, Logistic and Richards functions were considered for data fitting. Three functions were compared by adjusted determination coefficient (R2) and root mean square error (RMSE). For all three models, R2 had high values, ranging from 0.987 to 0.999. The difference among the fitted functions by RMSE was significant compared to the R2. The Richards function had more appropriate description for the growth curve of the Cobb strain, because of having the minimum RMSE, 61.57 compared to 85.43 and 66.61, for Gompertz and Logistic functions, respectively. However, the Gompertz function with the maximum R2, and the minimum RMSE, 73.32 and 3237, respectively, was the most suitable function to describe the growth curve of Arbor Acres strain
Chemical stimulation of the lateral hypothalamus potentiated the sensitization to morphine in rats
Orexin plays a crucial role in drug-seeking behavior. The lateral hypothalamus (LH) is a central region that produces orexin, and its projections to the ventral tegmental area (VTA) play an important role in reward and
addiction-related behaviors. In this study, we investigated the role of LH stimulation and the involvement of the orexin-1 receptor (Ox1r) in the VTA in relation to morphine sensitization. In all animals, cannulae were
implanted unilaterally into the LH and VTA to inject different doses of carbachol (62.5, 125 and 250 nmol/0.5
μl saline) as a cholinergic agonist and SB334867 (1, 10 and 20 nmol/0.3 μl DMSO) as a selective Ox1r antagonist for three consecutive days (sensitization period) respectively. These drugs were injected five minutes before administration of an ineffective dose of morphine (0.5 mg/kg; sc) during the sensitization period. In all groups, the sensitization period occurred in a separate room from which the conditioning occurred. After this period, all groups exceeded five days under the conditioned place preference (CPP) paradigm without any treatment. For evaluation of morphine sensitization, place preference was induced by ineffective dose of morphine (0.5 mg/kg) and the CPP score was represented by the difference in time spent in drug- and saline-paired compartments. The results revealed that concurrent intra-LH administration of carbachol (125 nmol/0.5 μl saline) and an ineffective dose of morphine (0.5 mg/kg) significantly induce CPP. Additionally, the blockade of Ox1r in the VTA by SB334867 can attenuate the conditioning score induced by concurrent administration of carbachol and an ineffective dose of morphine. Our findings suggest that LH stimulation potentiates the effect of an ineffective dose of morphine, and induces morphine sensitization. It seems that the chemical stimulation of LH potentiates sensitization to morphine through the orexinergic system in the VTA in rats
Preparation and Physicochemical Evaluation of Cochleate-based Carriers for Insulin
Introduction: Cochleates are cylindrical lipid structures that are more stable against oxidation and temperature than liposomes. Our research is formulation of cochleates for oral delivery of insulin as a model protein drug. Protein drugs are softer from environmental degradation and poor oral absorption; therefore any carrier system for their oral delivery must have protection against enzymes and absorption enhancing ability.
Methods and Results: In this study, liposomes with different proportion of lipids (DPPC and DMPC) and cholesterol were prepared by film hydration method and converted to cochleates by hydrogel method with CaCl2 and MgCl2. Microscopically observation of structures was carried out by phase-contrast microscope and Scanning Electron Microscope (SEM). Physicochemical characteristics of these structures were evaluated by measuring size distribution using with laser light scattering technique, entrapment efficiency percentage, investigation of release profile, and stability of selected cochleates. HPLC method was used for analytical evaluation of entrapped and released insulin.Best formulation of liposomes contains 70% of lipid and 30% of cholesterol. According to microscopic size distribution, cochleates with CaCl2 bridges were better. The size of vesicles was less than 6 µm. Insulin entrapment efficiency of cochleates with DPPC was more than DMPC type. Between 60-70% of encochleated insulin released after 2-4 hours in a buffer with pH 6.8.
Conclusions:The results shows that cochleates can be suitable oral delivery systems for insulin
Amphotericin-B and vancomycin-loaded chitosan nanofiber for antifungal and antibacterial application
In the present study, a mucoadhesive non-woven fiber mat (d= 116 nm) was fabricated by the electrospinning method using chitosan (80% Wt), polyethylene oxide (10% Wt), cysteine (4% Wt) and drugs (6% Wt), respectively. In addition, a comparative study was conducted to define effect of drugs and mucoadhesive agent on the nanofiber formation. FTIR, SEM, DSC and DMA were used to investigate the chemical and physical properties of the nanofibers. In vitro release of the drugs was assessed over a 48-hour period by the total immersion method. Release data were fitted to kinetic models, including the zero-order, first-order, Higuchi matrix, and Hixson–Crowell. Zone inhibition investigations were used to describe the inhibition content of vancomycin and amphotericin B loaded in the mats. The SEM images displayed a slight decrease in the fiber diameter with adding drugs and mucoadhesive agents. FTIR spectra confirmed that any undesirable reaction between VAN–AMB and CS-PEO was not observed. DSC test recognized the uniform distribution of drugs in the polymeric bead of the fiber without any crystal form. The elasticity modulus of the nanofiber was in an acceptable range for oral mucosa (approximately 5 Mpa). The results indicated that biodegradable mucoadhesive nanofibrous membranes released high concentrations of VAN in the first 24 hours, but the AMB release was affected in more controlled phenomena
Diagnostic and prognostic significance of ALU-based cell-free DNA in colorectal cancer: a systematic review and meta-analysis
IntroductionColorectal cancer (CRC) is a major global health concern. This study aimed to investigate the role of ALU-based cell-free DNA (cfDNA) in the diagnosis and prognosis of CRC.MethodsWe selected relevant literature from PubMed, Scopus, Web of Science, EMBASE, and Science Direct databases based on strict inclusion and exclusion criteria. 17 eligible studies were included in the final analysis (13 studies for diagnostic and 4 studies for prognostic meta-analysis). The search covered relevant publications up to July 1, 2024.ResultsThe pooled sensitivity, specificity, and diagnostic odds ratios (DOR) of ALU-based cfDNA in CRC diagnosis were 0.81 (95% CI= [0.70, 0.89]), 0.90 (95% CI= [0.70, 0.96]), and 40.58 (95% CI= [17.87, 92.19]), respectively. The area under the ROC curve was 0.92 (95% CI= [0.89, 0.94]). Patients with higher concentrations of plasma/serum ALU-based cfDNA had poorer overall survival (OS) (pooled hazard ratio = 2.33 ([95% CI= [1.80, 3.03]).ConclusionThe current evidence supports the utility of circulating ALU as a promising non-invasive diagnostic and prognostic tool for CRC. Furthermore, as a potential biomarker, ALU-based cfDNA could play a significant role in clinical application.Clinical implicationsThe evidence suggests that circulating ALU-based cell-free DNA (cfDNA) holds promise as a non-invasive diagnostic and prognostic tool for colorectal cancer, potentially enhancing clinical decision-making.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifier PROSPERO (CRD42023486369)
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