91 research outputs found

    A new approach for cell formation and scheduling with assembly operations and product structure

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    In this paper, a new formulation model for cellular manufacturing system (CMS) design problem is proposed. The proposed model of this paper considers assembly operations and product structure so that it includes the scheduling problem with the formation of manufacturing cells, simultaneously. Since the proposed model is nonlinear, a linearization method is applied to gain optimal solution when the model is solved using direct implementation of mixed integer programming. A new genetic algorithm (GA) is also proposed to solve the resulted model for large-scale problems. We examine the performance of the proposed method using the direct implementation and the proposed GA method. The results indicate that the proposed GA approach could provide efficient assembly and product structure for real-world size problems

    The susceptibility of Streptococcus mutans to antibacterial photodynamic therapy: a comparison of two different photosensitizers and light sources

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    Streptococcus mutans is the main etiological agent for dental caries. Recently, photodynamic therapy (PDT) has been introduced as a new modality in bacterial decontamination. Objective: This in vitro study was carried out to evaluate the susceptibility of Streptococcus mutans to antibacterial PDT using two different photosensitizers and light sources. Material and Methods: Standard suspensions of S. mutans were exposed to laser light at 662 nm and Radachlorin® or LED 630 nm in combination with Toluidine blue O (TBO). Radiation-only groups, photosensitizer alone, and groups with no treatment were used as controls. Bacterial suspension from each treatment was subcultured onto the surface of Mueller-Hinton agar plates and bacterial growth was assessed. The results were analyzed by analysis of variance and Tukey test (

    Seroprevalence and Molecular Evaluation of Toxoplasmosis in Patients Undergoing Chemotherapy for Malignancies in the Bushehr Province, Southwest Iran

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    Background: Toxoplasmosis is a life-threatening infection in organ transplant recipients, people receiving corticosteroid or radiation therapy, people with malignancies, and AIDS patients. Objectives: The current study aimed to determine the prevalence of toxoplasmosis in patients receiving chemotherapy for malignancies in the Bushehr province of southwest Iran. Methods: Blood samples were taken from 86 patients who were continuously referred to the chemotherapy center in Bushehr province and evaluated by ELISA to determine anti-Toxoplasma IgG and IgM antibodies. Moreover, a blood buffy coat of each sample was assessed by polymerase chain reaction (PCR), targeting a 529 bp gene of T. gondii. PCR products of the positive samples were sequenced to determine the genotype of the parasite. Results: Anti-Toxoplasma IgG antibodies were detected in the sera of 21 (24.4%) cases. All of the patients were negative for anti- Toxoplasma IgM antibodies. No statistically significant correlation was found between seropositivity to Toxoplasma and duration of chemotherapy or having contact with cats. PCR detected a 529 bp band of T. gondii in the buffy coats of two out of 86 (2.3%) cases. The sequence analysis demonstrated that both cases were 95% identical to type III (VEG strain) of T. gondii. Conclusions: Findings of this study demonstrated the presence of type III T. gondii in the buffy coats of patients undergoing chemotherapy. Given that toxoplasmosis is a life-threatening infection in immunocompromised patients, these patients should be screened for toxoplasmosis before and during chemotherapy to prevent acute toxoplasmosi

    Seroprevalence and Molecular Evaluation of Toxoplasmosis in Patients Undergoing Chemotherapy for Malignancies in the Bushehr Province, Southwest Iran

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    Toxoplasmosis is a life-threatening infection in organ transplant recipients, people receiving corticosteroid or radiation therapy, people with malignancies, and AIDS patients. Objectives: The current study aimed to determine the prevalence of toxoplasmosis in patients receiving chemotherapy for malignancies in the Bushehr province of southwest Iran. Methods: Blood samples were taken from 86 patients who were continuously referred to the chemotherapy center in Bushehr province and evaluated by ELISA to determine anti-Toxoplasma IgG and IgM antibodies. Moreover, a blood buffy coat of each sample was assessed by polymerase chain reaction (PCR), targeting a 529 bp gene of T. gondii. PCR products of the positive samples were sequenced to determine the genotype of the parasite. Results: Anti-Toxoplasma IgG antibodies were detected in the sera of 21 (24.4%) cases. All of the patients were negative for anti- Toxoplasma IgM antibodies. No statistically significant correlation was found between seropositivity to Toxoplasma and duration of chemotherapy or having contact with cats. PCR detected a 529 bp band of T. gondii in the buffy coats of two out of 86 (2.3%) cases. The sequence analysis demonstrated that both cases were 95% identical to type III (VEG strain) of T. gondii. Conclusions: Findings of this study demonstrated the presence of type III T. gondii in the buffy coats of patients undergoing chemotherapy. Given that toxoplasmosis is a life-threatening infection in immunocompromised patients, these patients should be screened for toxoplasmosis before and during chemotherapy to prevent acute toxoplasmosis

    Midazolam Enhances Ureter Visualization in Children Undergoing Magnetic Resonance Urography

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    Introduction: Magnetic Resonance Urography (MRU) is a popular method for identifying uropathies in children. Some children are not cooperative for such examinations and are sedated. We decided to evaluate the effects of midazolam as a sedative drug on ureter visualization in patients undergoing MRU.Materials and Methods: The study was conducted in Paytkaht Medical Imaging Center, Tehran, Iran. Two hundred and three children with urologic diseases were divided into 2 groups. Patients in the non-cooperative group received midazolam prior to MRU.Results: Our findings showed that non-cooperative children had a better ureter visualization on MRU (P<0.01).Conclusions: Midazolam increased ureter visualization possibly by reduction in the ureter peristaltic motility. Therefore, its use could shorten the duration of MRU. It is beneficial to use midazolam in all children who undergo MRU.Keywords:  Diagnostic Imaging, MRI; Urography; Midzolam; Child; Ureter

    Effects of opium inhalation on pulmonary volumes in smoking patients

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           Historically, opium was used as a potent analgesic and to treat dyspnea and cough. It is documented that opium can increase exercise tolerance and relieve breathlessness. However, its overdose can suppress respiratory centers. The purpose of this study was to evaluate effects of opium on spirometric lung volumes.The study was done on two groups of patients referred to the lung clinic of Labbafi Nejad hospital. Group A was composed of 84 patients who were smokers and group B was made up of 40 patients who were smokers and opium addicts. Patients underwent spirometry and demographic questionnaires were collected. Significant differences were noted on lung volumes between two groups. Forced Vital Capacity (FVC) was 56 ± 4.6 % in Group A and 72 ± 4.7 % in Group B (P < 0.001). Difference on Forced Expiratory Volume in one second (FEV1) was also statistically significant, 53 ± 6.6 % in Group A versus 69 ± 4.4 % in Group B (P < 0.001). In this study, lung volumes were considerably larger in patients who were opium addicts and smokers compared to patients who were only smokers. Further studies are warranted to confirm these results, and such confirmation may lead to better understanding about role of opioids in respiratory diseases.

    Molecular and Morphological Characterization of Fasciola

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    The current study aimed to find out the morphometric and genotypic divergences of the flukes isolated from different hosts in a newly emerging focus of human fascioliasis in Iran. Adult Fasciola spp. were collected from 34 cattle, 13 sheep, and 11 goats from Kohgiluyeh and Boyer-Ahmad province, southwest of Iran. Genomic DNA was extracted from the flukes and PCR-RFLP was used to characterize the isolates. The ITS1, ITS2, and mitochondrial genes (mtDNA) of NDI and COI from individual liver flukes were amplified and the amplicons were sequenced. Genetic variation within and between the species was evaluated by comparing the sequences. Moreover, morphometric characteristics of flukes were measured through a computer image analysis system. Based on RFLP profile, from the total of 58 isolates, 41 isolates (from cattle, sheep, and goat) were identified as Fasciola hepatica, while 17 isolates from cattle were identified as Fasciola gigantica. Comparison of the ITS1 and ITS2 sequences showed six and seven single-base substitutions, resulting in segregation of the specimens into two different genotypes. The sequences of COI markers showed seven DNA polymorphic sites for F. hepatica and 35 DNA polymorphic sites for F. gigantica. Morphological diversity of the two species was observed in linear, ratios, and areas measurements. The findings have implications for studying the population genetics, epidemiology, and control of the disease

    Monitoring of Virulence Factors and Metabolic Activity in Aggregatibacter Actinomycetemcomitans Cells Surviving Antimicrobial Photodynamic Therapy via Nano-Chitosan Encapsulated Indocyanine Green

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    Aggregatibacter actinomycetemcomitans is an etiological agent frequently found in both chronic and aggressive periodontitis as well as peri-implantitis. This study assessed the effect of antimicrobial photodynamic therapy (aPDT), as an alternative treatment modality, by nano-chitosan encapsulated indocyanine green (CNPs/ICG), as a photosensitizer, on the virulence features of cell-surviving aPDT against A. actinomycetemcomitans. The cell cytotoxicity effect of CNPs/ICG was evaluated on primary human gingival fibroblast cells. A. actinomycetemcomitans ATCC 33384 photosensitized with CNPs/ICG was irradiated with diode laser at a wavelength of 810 nm for 1 min (31.2 J/cm2), and then bacterial viability measurements were done. The biofilm formation ability, metabolic activity, and antimicrobial susceptibility profiles were assessed for cell-surviving aPDT. The effect of aPDT on the expression of the fieF virulent gene, encoding the ferrous-iron efflux pump, was evaluated by the quantitative real-time PCR. CNPs/ICG-aPDT resulted in a significant reduction of cell viability (91%), biofilm formation capacity (53%), and metabolic activity (48%) of A. actinomycetemcomitans when compared to the control group (P < 0.05). Moreover, fieF gene expression was downregulated by 14.8 folds after the strains were treated with aPDT. The virulence of A. actinomycetemcomitans strain reduced in cells surviving aPDT with CNPs/ICG, indicating the potential implications of aPDT for the treatment of A. actinomycetemcomitans infections in periodontitis and peri-implantitis in vivo

    Synergistic impact of motion and acquisition/reconstruction parameters on F-18-FDG PET radiomic features in non-small cell lung cancer:Phantom and clinical studies

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    Objectives: This study is aimed at examining the synergistic impact of motion and acquisition/reconstruction parameters on 18 F-FDG PET image radiomic features in non-small cell lung cancer (NSCLC) patients, and investigating the robustness of features performance in differentiating NSCLC histopathology subtypes. Methods: An in-house developed thoracic phantom incorporating lesions with different sizes was used with different reconstruction settings, including various reconstruction algorithms, number of subsets and iterations, full-width at half-maximum of post-reconstruction smoothing filter and acquisition parameters, including injected activity and test-retest with and without motion simulation. To simulate motion, a special motor was manufactured to simulate respiratory motion based on a normal patient in two directions. The lesions were delineated semi-automatically to extract 174 radiomic features. All radiomic features were categorized according to the coefficient of variation (COV) to select robust features. A cohort consisting of 40 NSCLC patients with adenocarcinoma (n = 20) and squamous cell carcinoma (n = 20) was retrospectively analyzed. Statistical analysis was performed to discriminate robust features in differentiating histopathology subtypes of NSCLC lesions. Results: Overall, 29% of radiomic features showed a COV ≤5% against motion. Forty-five percent and 76% of the features showed a COV ≤ 5% against the test-retest with and without motion in large lesions, respectively. Thirty-three percent and 45% of the features showed a COV ≤ 5% against different reconstruction parameters with and without motion, respectively. For NSCLC histopathological subtype differentiation, statistical analysis showed that 31 features were significant (p-value &lt; 0.05). Two out of the 31 significant features, namely, the joint entropy of GLCM (AUC = 0.71, COV = 0.019) and median absolute deviation of intensity histogram (AUC = 0.7, COV = 0.046), were robust against the motion (same reconstruction setting). Conclusions: Motion, acquisition, and reconstruction parameters significantly impact radiomic features, just as their synergies. Radiomic features with high predictive performance (statistically significant) in differentiating histopathological subtype of NSCLC may be eliminated due to non-reproducibility.</p

    Photodynamic Inactivation of Porphyromonas gingivalis utilizing Radachlorin and Toluidine Blue O as Photosensitizers: An In Vitro Study

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    Introduction: Porphyromonas gingivalis is one of the major pathogens in the development and progression of periodontal disease. Antimicrobial photodynamic therapy (aPDT) is a new approach which is sorted in non-invasive phototherapy for bacterial elimination. This in vitro study was conducted to compare photodynamic inactivation using Radachlorin and Toluidine blue O (TBO) as photosensitizers on P. gingivalis.Methods: Bacterial suspensions (200 μL) of P. gingivalis were exposed to either TBO with concentration of 0.1 mg/mL associated with portable light-emitting diode (LED) device (peak wavelength: 630 nm, output intensity: 2.000 mW/cm2, tip diameter: 6.2 mm) or 0.1% Radachlorin® and laser irradiation (InGaAlP, Peak wavelength: 662±0.1% nm, output power: 2.5 W, energy density: 6 J/cm2, fiber diameter: 2 mm). Those in control groups were subjected to laser irradiation or LED alone, Radachlorin® or TBO alone, and one group received neither photosensitizer nor light irradiation. Then counting of colony forming units (CFU) was performed to determine the bactericidal effects in each subgroup.Results: LED-based aPDT reduced the colony count of P. gingivalis more than that of TBO (P &lt; 0.001) or LED group (P = 0.957). Also, laser-based aPDT had a great reduction in colony count of P. gingivalis in comparison with Radachlorin® (P &lt; 0.001) or laser irradiation alone (P = 0.28). In addition, the colony count reduction of laser-based aPDT was significantly more than LED-based aPDT (P &lt; 0.05).Conclusion: Considering the results of this study, the viability of P. gingivalis was more affected by the combination of laser and Radachlorin® 0.1% in comparison with LED and TBO 0.1
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