76 research outputs found

    A hybrid meta-heuristic algorithm for the vehicle routing problem with stochastic travel times considering the driver's satisfaction

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    A vehicle routing problem is a significant problem that has attracted great attention from researchers in recent years. The main objectives of the vehicle routing problem are to minimize the traveled distance, total traveling time, number of vehicles and cost function of transportation. Reducing these variables leads to decreasing the total cost and increasing the driver's satisfaction level. On the other hand, this satisfaction, which will decrease by increasing the service time, is considered as an important logistic problem for a company. The stochastic time dominated by a probability variable leads to variation of the service time, while it is ignored in classical routing problems. This paper investigates the problem of the increasing service time by using the stochastic time for each tour such that the total traveling time of the vehicles is limited to a specific limit based on a defined probability. Since exact solutions of the vehicle routing problem that belong to the category of NP-hard problems are not practical in a large scale, a hybrid algorithm based on simulated annealing with genetic operators was proposed to obtain an efficient solution with reasonable computational cost and time. Finally, for some small cases, the related results of the proposed algorithm were compared with results obtained by the Lingo 8 software. The obtained results indicate the efficiency of the proposed hybrid simulated annealing algorithm

    Root Canal Morphology of Maxillary Second Molars according to Age and Gender in a Selected Iranian Population: A Cone-Beam Computed Tomography Evaluation

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    Introduction: This study sought to assess root canal morphology of maxillary second molars regarding age and gender in an Iranian population using cone-beam computed tomography (CBCT). Methods and Materials: Totally, 157 maxillary second molars of patients presenting to a radiology clinic were evaluated on CBCT scans. Tooth length, number of roots, root fusion, coronal and sagittal root deviation, number of canals per root, prevalence of second mesiobuccal canal, root canal morphology according to the Vertucci’s classification and the correlation of these variables with age and gender were evaluated. Data were analyzed using the Mann Whitney U, Kruskal Wallis and Fisher’s exact tests. Results: Of 157 teeth, 98 belonged to females and 59 to males. The mean tooth length was significantly greater in males than in females (P=0.002) and it was shorter in 50-60 years old group. The rate of root fusion was 18.6%. Distobuccal and palatal roots were mainly straight in both sagittal and coronal planes while mesiobuccal roots mostly had a distal-buccal deviation; 67.5% of the teeth had four canals. Number of canals was significantly correlated with gender and was higher in males (P<0.05). The most prevalent canal type was type VI in second mesiobuccal, and type V in palatal and distobuccal canals. The most common types in mesiobuccal canal were types I, VI and II, respectively. In the remaining two roots, type I was the most common. Conclusion: Root and canal morphology of the maxillary second molars in Iranian population showed features different from those in other populations.Keywords: Age; Cone-Beam Computed Tomography; Gender; Maxillary Second Molar; Root Canal Anatomy; Root Canal Morpholog

    Effect of different dietary levels of rosemary (Rosmarinus officinalis) and yarrow (Achillea millefolium) on the growth performance, carcass traits and ileal microbiota of broilers

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    The effect of increasing dietary levels of rosemary and yarrow herb powders on the growth performance, carcass traits and ileal microbiota of broilers was studied. Three hundred and thirty-six one-day-old Ross 308 male chickens were allocated to one of the following treatments (six replicates of 8 birds per treatment): control (basal diet with no rosemary or yarrow herbs added), and basal diet with the addition of either 0.5, 1.0 or 1.5% of rosemary herb, or 0.5, 1.0, or 1.5% of yarrow herb. Significant differences were observed (P0.05) were found in the final body weight or in most of the carcass traits. The gastrointestinal tract weight, relative to body weight, increased (P&lt;0.05) due to rosemary and yarrow supplementation, compared with the control treatment. At 42 days of age, the rosemary supplementation increased the <em>Lactobacilli</em> counts and decreased the <em>Escherichia</em> <em>coli</em> counts more than the control and yarrow supplemented treatments. In conclusion, under the conditions of the present work, yarrow supplementation mainly improved growth performance, while rosemary supplementation showed the best effects on ileal microbiota, both compared with the control treatment

    Revolutionary Dentistry through Blockchain Technology

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    open access articleMultitudinous health data are continually being produced as our activities, including medicine, evolve into the digital age where data plays a decisive role. Challenges come along as well, concerning the collection, secure storage, verification and secure access to the continuously growing data at such a broad scale before valuable information can be extracted to contribute to medical advancement nowadays. With the decentralization feature, huge successes of blockchain technology in overcoming similar challenges in the finance and cryptocurrency sector brought us the confidence to investigate and reveal its immeasurable potential for the health sector, specifically in dentistry. Dentistry is an important area of healthcare, but there is relatively little research focusing on its interactions with blockchain technology. Given the limited amount of existing research on this specific subject, this paper focuses on blockchain in dentistry and aims to provide a conceptual framework for the possible applications of blockchain in dentistry. The framework is organised by different areas of dentistry operations so that dental professionals can easily refer to and identify areas of interest. This contributes to increasing the awareness of blockchain technology among dental professionals and promoting blockchain-empowered revolutions in dentistry. This paper also discusses how blockchain fits alongside other emerging technologies, the challenges that have to be overcome to maximise the functionality and efficiency of this technology, as well as future research directions concerning blockchain implementations in the dental industry

    Analysis of different signal peptides for the secretory production of Ama r 2 in gram-positive systems (Lactococcus lactis)

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    Prokaryotic systems have been considered the most affordable and simplest hosts which are being employed to express recombinant proteins such as allergens; nevertheless, without appropriate signal peptide (SP), these systems cannot be used for secretory proteins. Recently, a lot of effort has been put into assessing the potential of gram-positive strains such as lactic acid bacteria for new applications in the production of heterologous proteins. Ama r 2 is a respiratory allergen from Amaranthus retroflexus, whose recombinant production in the probiotic host could be introduced as a specific and effective way to rapid diagnosis and immunotherapy of this allergy. Consequently, the production of this recombinant protein using the prokaryotic system, requires a suitable SP to protect disulfide bonds and to prevent misfolding. This study was designed to predict the best SPs for the expression of Ama r 2 protein in Lactococcus lactis as the host. In this study, 42 signal sequences were selected from SP databases and the most important features of them were evaluated. First, n, h and c regions of the SPs and their probabilities were investigated by signalP software version 4.1. Then, their physicochemical properties were evaluated by Portparam and SOLpro. Moreover, the secretion sorting and sub-cellular localization sites were evaluated by PRED-TAT and ProtcompB software programs. The results revealed that yjgB, entC2 (Entrotoxine type C-2), ent B (Entrotoxine type), blaZ (Beta lactamase), dex (number 21), blm (Beta lactamase 2), dex (Dextranase; number 20) and number 26 were introduced theatrically as the best SPs to express Ama r 2 in Lactococcus lactis

    Short-term complications of anesthetic technique used in hip fracture surgery in elderly people

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    Postoperative complications of fracture are one of the main problems in older patients with hip fracture. In this study, complications were observed 48 hours after surgery in different anesthetic procedures. This prospective cross sectional study was carried out over a 12-month period. All subjects over 55 years of age undergoing hip fracture surgery were selected for study with ASA class (American Society of Anesthesiology: one, two and three). After determining the vital signs in the operating room, anesthesia type (general, spinal and epidural) and various variables were recorded. It was observed that the spinal anesthesia method had the lowest level of postoperative disturbances of consciousness and had the shortest duration in terms of duration of time. On the other hand, general anesthesia was the least in terms of blood transfusion. Finally, epidural anesthetic method showed the least amount of pain 48 hours after operation and the least changes in blood pressure and heart rate

    Response of Coker (flue-cured) tobacco (Nicotiana tabacum) to inoculation with Azotobacter chroococcum at various levels of nitrogen fertilization

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    Abstract A field study was carried out during a two-year period (2008 to 2009) in order to investigate on response of Coker 347 (flue-cured) tobacco plant (Nicotiana tabacum L.) in vegetative growth stages to inoculation with Azotobacter chroococcum at various levels of nitrogen (N) fertilization. In a factorial trial and randomized completely block design (RCBD), four levels of N fertilizer (nonfertilizer, 15, 30 and 45 kg ha -1 ) and three levels of Azotobacter chroococcum (non-inoculation, 1 and 2 kg ha -1 ) in Coker (flue-cured) tobacco with three replications per treatments were applied. Sampling was done in three positions of leaves (priming, cutter and tip). Results revealed that the effect of year of experiment was significant on quantitative characteristics (except leaf length), N uptake and qualitative characteristics (except nicotine in priming). Application of N had significant effect on quantitative characteristics (except number and width of Leaf), N uptake and qualitative characteristics. Inoculation of roots with bacterium had significant effect on Cured leaf weight of cutter, yield, N uptake and qualitative characteristics. Furthermore, the lowest content of leaf length and nicotine in priming and the highest content reducing sugar in priming and tip were observed in non-fertilizer treatment. On the other part, the highest content of nicotine in priming and the lowest content of sugar in priming and tip were observed in treatment with 45 kg.ha -1 N and 2 kg ha -1 bacterium. In general, Azotobacter chroococcum is a suitable inoculant for tobacco cultivation and it could be a strategy to achieve sustainable agriculture

    Graph cut segmentation method and its application in medical images

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    Graph cut is an interactive segmentation method. It works based on preparing graph from image and finds the minimum cut for the graph. The edges value is calculated based on belonging a pixel to object or background. The advantage of this method is using the cost function. If the cost function is clearly described, graph cut is presents a generally optimum result. In this paper graph concepts and preparing graph according to image pixels is described. Preparing different edges and performing min cut/max flow is explained. Finally, the method is applied on some medical images

    A Comparative Analysis of Clinical Characteristics and Laboratory Findings of COVID-19 between Intensive Care Unit and Non-Intensive Care Unit Pediatric Patients: A Multicenter, Retrospective, Observational Study from Iranian Network for Research in Viral

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    Introduction: To date, little is known about the clinical features of pediatric COVID-19 patients admitted to intensive care units (ICUs).&nbsp;Objective: Herein, we aimed to describe the differences in demographic characteristics, laboratory findings, clinical presentations, and outcomes of Iranian pediatric COVID-19 patients admitted to ICU versus those in non-ICU settings.&nbsp;Methods: This multicenter investigation involved 15 general and pediatrics hospitals and included cases with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection based on positive real-time reverse transcription polymerase chain reaction (RT-PCR) admitted to these centers between March and May 2020, during the initial peak of the COVID-19 pandemic in Iran.&nbsp;Results: Overall, 166 patients were included, 61 (36.7%) of whom required ICU admission. The highest number of admitted cases to ICU were in the age group of 1–5 years old. Malignancy and heart diseases were the most frequent underlying conditions. Dyspnea was the major symptom for ICU-admitted patients. There were significant decreases in PH, HCO3 and base excess, as well as increases in creatinine, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and potassium levels between ICU-admitted and non-ICU patients. Acute respiratory distress syndrome (ARDS), shock, and acute cardiac injury were the most common features among ICU-admitted patients. The mortality rate in the ICU-admitted patients was substantially higher than non-ICU cases (45.9% vs. 1.9%, respectively; p&lt;0.001).&nbsp;Conclusions: Underlying diseases were the major risk factors for the increased ICU admissions and mortality rates in pediatric COVID-19 patients. There were few paraclinical parameters that could differentiate between pediatrics in terms of prognosis and serious outcomes of COVID-19. Healthcare providers should consider children as a high-risk group, especially those with underlying medical conditions
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