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Abstract Background Pseudomonas aeruginosa is a major cause of healthcare-associated infections (HAIs), particularly in immunocompromised patients, leading to high morbidity and mortality rates. This study aimed to investigate the antimicrobial resistance patterns, virulence gene profiles, and genetic diversity among P. aeruginosa isolates from hospitalized patients in Mazandaran, Iran. Methods From September 2021 to April 2022, 82 non-duplicate P. aeruginosa isolates were collected from diverse clinical sources. Identification was confirmed using API 20 NE (bioMérieux, Marcy l’Etoile, France). Antimicrobial susceptibility testing was conducted using the Kirby-Bauer disk diffusion method according to CLSI guidelines to assess resistance to a range of antibiotics. The virulence profile (exoT, exoY, exoU, toxA, plcH, plcN, algD, aprA, lasB and exoS) of each P. aeruginosa isolate was determined by PCR. The genetic diversity among the strains was evaluated using the random amplification of polymorphic DNA (RAPD) technique. Clustering was based on a Dice similarity coefficient of ≥ 85%. Results Of the 82 total strains, P. aeruginosa exhibited the highest and lowest resistance toward ticarcillin-clavulanate (98.78%) and colistin (0%), respectively. Moreover, 100% of the P. aeruginosa isolates were MDR. The following prevalence of virulence factor genes was observed: aprA, lasB, algD, toxA, plcH, exoY, and exoT in 100% of isolates. The plcN, exoS, and exoU were identified 98.78%, 67.07%, and 45.12%, respectively. The RAPD patterns obtained with primers 272 and 208 had respectively 2–19 and 6–17 bands. According to the Dice similarity coefficient of higher than 85%, 56 and 39 clusters were recognized. Conclusion The high rate of multidrug resistance combined with the widespread presence of virulence genes in P. aeruginosa isolates highlights the potential for increased infection severity, morbidity, and mortality in hospitalized patients. The substantial genetic diversity observed among isolates suggests that P. aeruginosa in this region may rapidly evolve, necessitating ongoing surveillance and more targeted antimicrobial strategies. Clinical trial number Not applicable.

Background and purpose: Acinetobacter species have emerged as major causes of nosocomial infections. Acinetobacter baumannii, the most common clinical subspecies, can cause a wide range of nosocomial infections, including pneumonia, bloodstream infections, and wound infections. These infections are often associated with high mortality rates due to the increasing prevalence of drug resistance among these bacteria. The production of β-lactamases is a significant mechanism of resistance to β-lactams. The transcription of these β-lactamase genes is enhanced by various insertion sequences (ISs) located nearby. The insertion sequences most commonly associated with carbapenem genes in multidrug-resistant Acinetobacter baumannii isolates are ISAba1, ISAba2, ISAba3, ISAba4, and IS18. This study aimed to evaluate the drug resistance patterns and molecular detection of ISAba1 and ISAba2 insertion sequences in A. baumannii isolates recovered from hospitalized patients in Sari teaching hospitals. Materials and methods: This study was conducted over six months, from March 2022 to August 2022, in Sari teaching hospitals. Ninety A. baumannii isolates were collected from various clinical specimens of hospitalized patients. To confirm the species of A. baumannii, various phenotypic tests such as TSI, oxidase, MR/VP, OF, urea, citrate, and SIM were employed. The antibiotic susceptibility pattern of the isolates was evaluated using the disk diffusion method according to the CLSI 2021 guidelines. The minimum inhibitory concentration (MIC) of colistin was determined using the micro broth method. To evaluate the presence of ISAba1 and ISAba2 genes, the Polymerase Chain Reaction (PCR) method was performed using specific primers. Data were analyzed using SPSS version 22 software. The chi-square test was used to determine significant differences, with a P-value less than or equal to 0.05 considered statistically significant. Results: The results of this study showed that A. baumannii isolates had a high level of resistance to several antibiotics, including ciprofloxacin, imipenem, doripenem, cefepime, ceftazidime, piperacillin/tazobactam, and piperacillin, with all isolates (100%) being resistant to these antibiotics. However, the highest susceptibility was observed for the antibiotic colistin (98.8%). Additionally, the frequencies of ISAba1 and ISAba2 genes among the isolates were 95.5% and 81.1%, respectively, indicating a high prevalence of these genetic elements among the study isolates. Conclusion: The results of this study indicate a high susceptibility of isolates to the antibiotic colistin, but due to the risk of resistance development and nephrotoxicity, it should be used with caution. The findings suggest that the presence of insertion elements such as ISAba1 and ISAba2 plays a significant role in increasing the expression of drug-resistance genes and their transfer in Acinetobacter baumannii. This can help explain the high prevalence of drug resistance in these bacteria and highlights the importance of detecting and controlling these factors to reduce nosocomial infections. Therefore, identifying and controlling these factors can be an effective step in improving prevention and treatment methods for infections caused by A. baumannii.

Aims: Pseudomonas aeruginosa plays an important role in hospital infections caused by several virulence factors, such as elastase and proteases. This study aimed to evaluate the prevalence of LasA, LasB, and PIV genes, encoding these enzymes, in clinical isolates of P. aeruginosa. Materials and methods: One hundred clinical isolates were collected from patients admitted to educational and therapeutic hospitals of Mazandaran Province, North Iran. The isolates were identified by the standard microbiological and biochemical tests. The bacterial DNA was extracted by the alkaline lysis method, and the presence of relevant genes was detected using the PCR method. The data were analyzed using SPSS v. 23 and the chi-square test. A p-value

Objective: To investigate the frequency of exoU and exoY genes in patients with Pseudomonas aeruginosa infection. Methods: In this study, 100 clinical isolates of Pseudomonas aeruginosa were collected from patients hospitalized in educational-therapeutic hospitals and were identified using standard microbiological tests. Then, the antibiotic resistance pattern of the isolates was determined by the disk agar diffusion method. The bacterial DNAs were extracted by the alkaline lysis method. Finally, the presence of exoU and exoY genes was evaluated by the PCR test. Results: In this study, 47%, 72%, 29%, 39%, 40%, and 44% of the isolates were non-susceptible to piperacillin, aztreonam, ceftazidime, imipenem, tobramycin, and ciprofloxacin, respectively. In addition, 95% and 93% of the clinical isolates carried the exoU and exoY genes. Blood and fecal isolates had both virulence genes, while only one wound isolate had neither genes. Meanwhile, all urinary isolates contained the exoY gene and only one isolate lacked the exoU gene. Also, 88 isolates simultaneously had both exoU and exoY genes. Conclusions: High prevalence of exoU and exoY genes in this region indicates a significant role of type III secretion system in pathogenesis of Pseudomonas aeruginosa. The type III secretion system may be a suitable target to reduce the pathogenicity of this bacterium.

Background and purpose: Pseudomonas aeruginosa is an opportunistic nosocomial pathogen, which is resistant to different groups of antibiotics. Infections caused by this organism due to antibiotic resistance may ultimately cause high mortality. The ability of this microorganism to produce pathogenic factors such as alginate, proteases, pyocyanin, rhamnolipid, phospholipase C, the presence of pili, and the ability to form biofilm and colonization have made this bacterium one of the most important pathogens. Considering that alginate is one of the important pathogenic factors of this microorganism which mainly algA, algC, and algD genes encode enzymes necessary for the leading biosynthesis pathway of alginate-GDP-mannuronic acid. Therefore, in the current study, we investigated the frequency of the algD gene in P. aeruginosa isolated from patients hospitalized in Mazandaran hospitals using specific primers by PCR method. Materials and methods: According to the results of past studies and using the sample size formula to calculate the prevalence and considering the maximum error of 0.05, the confidence level of 0.95, the ratio of 0.97, and the sample size of the unlimited population was estimated to be 100 isolates. Clinical isolates of P. aeruginosa were collected from different laboratories of Mazandaran educational hospitals. After collecting the clinical isolates of P. aeruginosa and definitively identifying the bacteria by performing routine biochemical tests, the antibiotic resistance pattern of the isolates was checked with Agar Diffusion Disk. In the next step, we extracted the DNA of P aeruginosa strains by alkaline lysis method by adding sodium dodecyl sulfate and NaOH. Finally, a PCR test was performed using the specific primer of the algD gene. Then, the PCR product was evaluated using a UV Transilluminator device. Data were analyzed using SPSS software. Results: 100 isolates of P. aeruginosa were isolated from 100 hospitalized patients. These isolates were collected from five medical educational hospitals of Mazandaran province, which were as follows: Imam Khomeini Hospital in Sari (40 isolates), Razi Hospital in Qaemshahr (22 isolates), Bo Ali Sina Hospital in Sari (17 isolates), Zare Psychiatric and Burn hospital in Sari (11 isolates), and Fatemeh Zahra heart hospital in Sari (10 isolates). Most of the clinical isolates of P. aeruginosa in the present study were obtained from sputum samples (37/100) and in second place from urine samples (26/100) of patients. 98 isolates had the algD gene. 26% of isolates were resistant to Piperacillin, 39% of isolates to Aztreonam, 27% of isolates to Ceftazidime, 31% of isolates to Imipenem, 39% to Tobramycin and 41% to Ciprofloxacin. All clinical isolates resistant to studied antibiotics carried the algD gene. Only two isolates of the sensitive strains of this organism in each group of antibiotics lacked the desired gene. Conclusion: The results of the present study show that the algD gene is present in most of the clinical isolates of the P. aeruginosa strain obtained from medical education centers in Mazandaran. On the other hand, the high prevalence of this organism and the high resistance to antibiotics and multiple drugs observed in the current study and previous studies have turned the treatment of infections caused by P. aeruginosa into a serious and complex problem. Finally, considering that the algD gene plays a significant role in the formation of biofilm and antibiotic resistance, the results of the current study also confirm this finding.

Abstract Background Currently, antibiotic-resistant strains of Enterococcus are considered to be one of the critical health challenges globally. This study aimed to investigate the antibiotic susceptibility pattern, biofilm formation capacity, and virulence genes of enterococci isolated from different sources. Methods In this cross-sectional study, environmental and fecal samples were collected from the hospital environment, volunteers, and hospital staff from October 2018 to August 2019. The isolates were identified by morphological and biochemical tests (gram staining, catalase, bile resistance, esculin hydrolysis, carbohydrate fermentation, growth in 6.5% NaCl, Pyrrolidonyl arylamidase, arginine dehydrolase), and PCR for ddl gene. An antimicrobial susceptibility test was performed by the standard disk agar diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Quantitative microplate assays were used to assess biofilm production. The bacterial DNAs were extracted by alkaline lysis method and polymerase chain reaction technique was used detect the esp, ace, and efaA virulence genes. Results Out of 145 isolates, 84 (57.9%) were identified as E. faecalis and 61 (42.1%) as E. faecium. Resistance to kanamycin and quinupristin-dalfopristin was 82.1% (69/84) and 85.7% (72/84), respectively, in E. faecalis isolates. Out of 61 E. faecalis isolates, 38 (62.4%) were resistant to kanamycin. Among the E. faecalis isolates, esp was the most dominant virulence gene (73.80%), followed by efaA, and ace, which were detected in 60.71%, and 30.95% isolates, respectively. In total, 68.27% of the strains were biofilm producers. Further, esp and efaA genes were more frequently found among E. faecalis strains with moderate and strong biofilm biomass. Conclusions According to the findings of our study, enterococci strains isolated from different samples possess distinctive patterns of virulence genes. The esp, ace, and efaA genes were more prevalent among E. faecalis than E. faecium. Besides, the high level antibiotic resistance of normal flora and environmental enterococci strains is alarming the researchers.

Background and purpose: The occurrence of burn wound infection is a crucial concern in burn ward. The purpose of this study was to examine the prevalence and antibiotic resistance pattern of organisms causing burn wound infections in Zare Hospital of Sari. Materials and methods: A total number of 370 samples of burn wounds were collected and cultured, and the bacteria leading to the infection were identified. Subsequently, the bacteria's antibiotic resistance pattern was determined by means of the disk agar diffusion method. The obtained data were analyzed using Chi-square and Fisher statistical tests. Results: Out of 370 samples, 219 positive cultures (59.1%) were reported. The bacteria with the highest occurrence were Acinetobacter baumannii (39.26%), Enterobacter aerogenes (21.46%), and Citrobacter freundii (15.52%). However, tetracycline proved to be the most efficacious antibiotic, whereas A. baumannii emerged as the most resilient organism in this investigation. Conclusion: The findings of the present study revealed that the change in the prevalence of organisms isolated from burn wound infection and the relative increase of A. baumannii and E. aerogenes, and the high-level antibiotic resistance of the bacteria.

Background and purpose: The prevalence of bacterial infections and the type of bacteria involved in causing endocarditis and knowing their antibiotic resistance pattern are very important for the correct selection of antibiotics to treat these infections and the proper control of infection in the hospital. In this retrospective cross-sectional descriptive study, we investigated the antibiotic resistance pattern of bacterial agents isolated from blood cultures of patients with infective endocarditis. Materials and methods: This retrospective study was conducted on patients with infective endocarditis admitted to Razi and Fatemeh Zahra teaching hospitals over the four years from 2019 to 2023. After collecting the data, it was entered into Excel software and then analyzed using SPSS version 19 software. Results: Among 28 patients included in the study, 57.1% were men and 42.9% were women; the median age of patients was 56.79±13.41 years. The most common isolated microorganism was Staphylococcus aureus with 11 positive samples (39.2%). Ninety-three percent of the studied microorganisms were resistant to at least two drugs. The result of the treatment was not significantly related to any of the gender, type of valve, and type of isolated microorganism (P=0.624, P=1.000 and P=0.398, respectively). Conclusion: In this study, gram-positive bacteria were the most common group of microorganisms causing infective endocarditis. A high percentage of resistance was observed against some antibiotics including penicillin, ceftazidime, and ceftriaxone, which should be considered in initial empiric antibiotic therapy among hospitalized patients with infective endocarditis

Background and purpose: Ventilator-associated pneumonia (VAP) is of special importance among nosocomial infections. We aimed to study the bacterial profile of VAP and their drug susceptibility pattern among intensive care unit patients at teaching hospitals affiliated with Mazandaran University of Medical Sciences. Materials and methods: In this retrospective cross-sectional study, the records of patients in the intensive care unit with ventilator-associated pneumonia were reviewed. After the growth of the bacteria, the colony identification of the grown bacteria were done based on microbiological and biochemical standard tests. To investigate the antimicrobial susceptibility pattern of isolates, the disk diffusion method was used according to the CLSI guidelines. Results: Out of 107 patients, 14 (13%) had a history of hospitalization over the last three months. The most common underlying diseases were ischemic heart disease (IHD), hypertension, and diabetes. The most common causes of hospitalization included cardiac diseases, COVID-19, and sepsis. The most common microorganism isolated was Enterobacter (23.4%), and the least abundant microorganisms were Proteus (n=1) and Staphylococcus saprophyticus (n=1). In general, colistin was the most sensitive among the examined gram-negative organisms. Conclusion: Identifying the pattern of antibiotic resistance and the risk factors for ventilator-associated pneumonia are effective in delivering more efficient treatments and reducing the complications of this disease. Local epidemiological data should be collected at all centers as this information guides the initial empirical treatment with antibiotics, thereby preventing the development of more resistant strains. All these measures will reduce the morbidity and mortality of ventilator-associated pneumonia.

Background: Computed tomography (CT) of the brain is associated with radiation exposure to the lens of the eyes. Therefore, it is necessary to optimize scan settings to keep radiation exposure as low as reasonably achievable without compromising diagnostic image information. The aim of this study was to compare the effectiveness of the five practical techniques for lowering eye radiation exposure and their effects on diagnostic image quality in pediatric brain CT. Methods: The following scan protocols were performed: reference scan, 0.06-mm Pbeq bismuth shield, 30% globally lowering tube current (GLTC), reducing tube voltage (RTV) from 120 to 90 kVp, gantry tilting, and combination of gantry tilting with bismuth shielding. Radiation measurements were performed using thermoluminescence dosimeters. Objective and subjective image quality was evaluated. Results: All strategies significantly reduced eye dose, and increased the posterior fossa artifact index and the temporal lobe artifact index, relative to the reference scan. GLTC and RTV increased image noise, leading to a decrease signal-to-noise ratio and contrast-to-noise ratio. Except for bismuth shielding, subjective image quality was relatively the same as the reference scan. Conclusions: Gantry tilting may be the most effective method for reducing eye radiation exposure in pediatric brain CT. When the scanner does not support gantry tilting, GLTC might be an alternative.

Background and purpose: Production of beta-lactamase enzymes by bacteria, especially Extended-spectrum β-lactamases (ESBLs) is one of the major problems worldwide. ESBLs are mostly located on bacterial plasmids and it is recognized that SHV, TEM, and CTX-M are prevailing among them. The aim of this study was to determine the ability to produce ESBLs genes based on molecular method among non-fermenting Gram-negative bacteria (Pseudomonas aeruginosa and Acinetobacter baumannii) isolated from hospitalized patients in Mazandaran province, Iran. Materials and methods: In this cross-sectional descriptive study, 81 non-fermenting bacterial isolates were collected. The isolates were tested for antibiotic susceptibility according to CLSI guidelines. Molecular identification of blaSHV, blaTEM, and blaCTX-M genes was performed using specific primers and polymerase chain reaction (PCR) method. Results: Of 81 non-fermentative bacteria isolated, 49 (60.5%) isolates of A. baumannii were detected and 32 (39.5%) isolates were confirmed as P. aeruginosa. The prevalence of identified genes in these isolates was as follows: 26% blaSHV, 19% blaTEM, and 12% blaCTX-M in P. aeruginosa and 11% blaTEM, 8% blaCTX-M, and 4% blaSHV in A. baumannii. Conclusion: ESBL positive strains of P. aeruginosa and A. baumannii are increasingly found in hospital isolates. Their high ability to pass resistant genes to other clinical strains requires their quick detection in clinical laboratories.

In this study a direct electrochemical copolymerization of pyrrole-formyl pyrrole (Py-co-FPy) was carried out by copolymerization of formyl pyrrole and pyrrole in LiClO4 aqueous solution under constant current of 480 µA for 200 s. The (Py-co-FPy) copolymer was characterized using field emission scanning electron microscope (FESEM), energy-filtering transmission electron microscope (EFTEM), thermal gravimetric analysis (TGA) and Electrochemical Impedance Spectroscopy (EIS). The FESEM images showed that the synthesized copolymer had a hollow whelk-like helixes structure. Moreover, the whorls on the bodies of (Py-co-FPy) copolymer whelk have well-ordered periodic nanostructures that provides a great high ratio of surface to volume. The Impedance study results confirm that (Py-co-FPy) copolymer layer can improve the electron conduction 2.5 times higher than PPy. The conjugated structure between Py and FPy in the presence of methine group can cause the enhancement of conductivity compared to polypyrrole. TGA analysis reveals that the Py-co-PPy copolymer has more thermal stability compared to polypyrrole.

Abstract With the growing demands for personalized medicine and medical devices, nanomedicine is a modern scientific field, and research continues to apply nanomaterials for therapeutic and damaged tissue diagnosis. In this regard, substantial progress has been made in synthesizing magnetic nanoparticles with desired sizes, chemical composition, morphologies, and surface chemistry. Among these materials, nanomagnetic iron oxides have demonstrated promise as unique drug delivery carriers due to cancer treatment. This carrier could lead to responsive properties to a specific trigger, including heat, pH, alternative magnetic field, or even enzymes, through functionalization and coating of magnetic nanoparticles, along with biocompatibility, good chemical stability, easy functionalization, simple processing, and ability to localize to the tumor site with the assistance of external magnetic field. Current studies have focused on magnetic nanoparticles’ utilities in cancer therapy, especially for colorectal cancer. Additionally, a bibliometric investigation was performed on the public trends in the field of the magnetic nanoparticle to drug delivery and anticancer, which represented progressing applications of these carriers in the multidisciplinary zones with a general view on future research and identified potential opportunities and challenges. Furthermore, we outline the current challenges and forthcoming research perspective for high performance and fostering advanced MNPs in colorectal cancer treatment. Graphical Abstract

Abstract Background Klebsiella pneumoniae is one of the leading causes of hospital outbreaks worldwide. Also, antibiotic-resistant K. pneumoniae is progressively being involved in invasive infections with high morbidity and mortality. The aim of the current study was to determine antimicrobial susceptibility patterns and the incidence of resistance genes (integron types and β-lactamase-encoded genes) among clinical isolates of K. pneumoniae. Methods In this cross-sectional study, a total of 100 clinical samples were obtained from hospitalized patients in three teaching hospitals in the north of Iran, from November 2018 and October 2019. Antimicrobial susceptibility testing was performed using disk agar diffusion test in line with CLSI recommendations. For colistin, minimum inhibitory concentration (MIC) was determined using broth microdilution. Based on antibiogram, multi-drug resistant (MDR) and extensive-drug resistant (XDR) strains were detected. Finally, integron types and β-lactamase resistance genes were identified using polymerase chain reaction technique. Results The most and least clinical samples were related to the urine and bronchoalveolar lavage, respectively. Based on the antibiogram results, amikacin and gentamicin exhibited good activity against K. pneumoniae strains in vitro. The high resistance rate (93%) to ampicillin/sulbactam predicts the limited efficacy of this antibiotic, in the hospitals studied. Among all the 100 isolates, the frequency of MDR and XDR phenotypes were 58% and 13%, respectively, while no pan-drug resistant (PDR) strains were found. In the MDR K. pneumoniae strains, the prevalence of bla SHV , bla TEM , bla CTX-M-15 , bla KPC , bla OXA-48 , bla NDM β-lactamase genes were 91.4%, 82.7%, 79.3%, 29.3%, 36.2% and 6.9%, respectively, however 91.4% of the isolates were carrying int I gene. Class II and III integrons were not detected in any isolates. Conclusion The MDR K. pneumoniae is becoming a serious problem in hospitals, with many strains developing resistance to most available antimicrobials. Our results indicate co-presence of a series of β-lactamase and integron types on the MDR strains recovered from hospitalized patients. The increasing rate of these isolates emphasizes the importance of choosing an appropriate antimicrobial regimen based on antibiotic susceptibility pattern.

Introduction: Hyperkyphosis is known to interfere with the normal function of the trunk musculature in the elderly. Although the effectiveness of orthoses in improving posture and balance in hyperkyphotic elderly people has received much attention, the effect of an orthosis on motor control of muscles remains unknown. This study aimed to evaluate changes in motor control strategies of trunk muscles during walking in elderly hyperkyphotic subjects after using an anatomical posture control (APC) orthosis. Materials and Methods: A total of 19 elderlies (11 women and 8 men) with thoracic hyperkyphosis of more than 45 degrees were enrolled in the study. Surface electromyography (EMG) signals were recorded from 6 trunk muscles bilaterally with and without orthosis. The voluntary response index (VRI) was calculated from quantitative analysis of surface electromyography (sEMG) data during level walking in those with and without orthosis. The outcome variables of VRI included the similarity index (SI) and electromyographic magnitude (MAG) of muscle groups. The effects of APC orthosis on trunk motor control were tested using a Wilcoxon non-parametric test. Cohen’s d effect sizes were also calculated. Results: A significant improvement was observed (P

The inevitable use of medical imaging examinations and lack of a suitable alternative lead to the need to control and minimize the amount of radiation from such artificial medical sources. To assess the relation between exposure parameters and lifetime of radiology devices, quality control tests were carried out on 13 radiology devices in 11 general hospitals. In this study, a barracuda dosimeter, SE-43137 Sweden, was calibrated to measure and record the quantities of kVp, mAs and exposure parameters. In all the devices using applying the minimum and maximum values of kVp, the minimum and maximum values of the internal resistances were calculated. The lowest mR/mA for the device C was observed at a flow rate of 200 mA (equal to 2,425), while the highest value was for the device A (2) at a current intensity of 200 mA (equal to 14.625). By increasing the age of the device, the output of the device is reduced. Therefore, to compensate for this decrease in the output, higher exposure conditions are usually applied to the device, which can greatly increase the damage to the device.

Background and purpose: Antibiotic resistance of Klebsiella pneumoniae to quinolones is a serious concern in treatment of nosocomial infections. There are limited reports on the prevalence of plasmid-mediated quinolone resistance genes in K. pneumoniae clinical isolates from Iran. The aim of this study was to investigate the rate of resistance to fluoroquinolone antibiotics, and also the frequency of qnrA, qnrB, and qnrS genes among K. pneumoniae isolates collected from hospitalized patients in Sari, Iran. Materials and methods: In this descriptive cross-sectional study, bacterial isolates were identified by conventional methods and biochemical tests. Resistance to fluoroquinolone antibiotics was evaluated by disk diffusion method. After resistance assessment, amplification of qnrA, qnrB, and qnrS genes in isolates was performed by polymerase chain reaction (PCR). Results: We analyzed 90 isolates and the antibiotic resistance of fluoroquinolone included: nalidixic acid (55%), ciprofloxacin (36%), ofloxacin (31%), levofloxacin (29%), and norfloxacin (22%). The PCR showed that 47 (52%), 22 (25%), and 21(23%) isolates harbored qnrB, qnrA, and qnrS genes, respectively. Conclusion: The outbreak of plasmid-mediated quinolone resistance (PMQR) leads to expand and increases bacterial resistance to fluoroquinolones. Therefore, continuous monitoring of antibiotic sensitivity patterns of K. pneumoniae strains to these agents is necessary.

Abstract Background Klebsiella pneumoniae is a common cause of nosocomial infections. Antibiotic resistance and ability to form biofilm, as two key virulence factors of K. pneumoniae, are involved in the persistence of infections. The purpose of this study was to investigate the correlation between antimicrobial resistance and biofilm formation capability among K. pneumoniae strains isolated from hospitalized patients in Iran. Methods Over a 10-month period, a total of 100 non-duplicate K. pneumoniae strains were collected. Antibiotic susceptibility was determined by Kirby–Bauer disk diffusion method according to CLSI. Biofilm production was assessed by tissue culture plate method. Finally, polymerase chain reaction was conducted to detect four families of carbapenemase: bla IMP, bla VIM, bla NDM, bla OXA−48; biofilm formation associated genes: treC, wza, luxS; and K. pneumoniae confirming gene: rpoB. Results Most of the isolates were resistant to trimethoprim-sulfamethoxazole (52 %), cefotaxime (51 %), cefepime (43 %), and ceftriaxone (43 %). Among all the 100 isolates, 67 were multidrug-resistant (MDR), and 11 were extensively drug-resistant (XDR). The prevalence of the bla VIM, bla IMP, bla NDM, and bla OXA−48 genes were 7 , 11 , 5 , and 28 %, respectively. The results of biofilm formation in the tissue culture plate assay indicated that 75 (75 %) strains could produce biofilm and only 25 (25 %) isolates were not able to form biofilm. Among these isolates, 25 % formed fully established biofilms, 19 % were categorized as moderately biofilm-producing, 31 % formed weak biofilms, and 25 % were non-biofilm-producers. The antimicrobial resistance among biofilm former strains was found to be significantly higher than that of non-biofilm former strains (p

Purpose: The aim of this research was to calculate the fluence, dose equivalent (DE), and kerma of thermal, epithermal and fast photoneutrons separately, within ICRU soft-tissue-equivalent phantom in the radiotherapy treatment room, using MCNPX Monte Carlo code. Materials and Methods: For this purpose, 18 MV Varian Linac 2100 C/D machine was simulated and desired quantities were calculated on the central axis and transverse directions at different depths. Results: Maximum fluence, DE and kerma of total photoneutrons on central axis of the phantom were 43.8 n.cm-2.Gy-1, 0.26, and 3.62 mGy.Gy-1, at depths 2, 0.1, 0.1 cm, respectively. At any depth, average of fluence, DE and kerma in the outer area of the field were less than the inner area and in general were about 72%, 52%, and 45%, respectively. Conclusion: According to this research, within the phantom; variation of fluence, DE and kerma in transverse direction were mild, and along the central axis at shallow area were sharp. DE of fast photoneutrons at shallow and deep areas were one order of magnitude greater than thermal photoneutrons.

Abstract Winding function (WF) method is one of the electric machines modelling methods, which is used to simulate electric machines under different conditions. It has less simulation time and memory than other methods and, at the same time, has comparable accuracy over other methods. One of the significant challenges of WF‐based models is how to model saturation. The accuracy of the fault detection method in electric machines depends on the accuracy of the model and the method used for the simulation. A new extended model of the WF is presented for saturation modelling, which considers all parts of the core including teeth, slots, and yokes. In this method, the effect of the iron parts is emulated as a partial value that is added to the length of the actual air gap. The simulation results for normal and faulty conditions are shown in two cases, with and without considering saturation effect. Then the importance of saturation modelling has been demonstrated. Simulation is done in MATLAB software. Moreover, the experimental results are shown to verify the proposed model.

Islanded microgrids as flexible, adaptive and sustainable smart cells of distribution power systems should be operated in accordance to both techno-economic purposes. Motivated by this need, the microgrid operators are in charge to elevate the active accommodation of both demand-side and supply-side distributed energy resources. To that end, in this paper, a new flexible frequency dependent energy management system is proposed through which distributed generators have time varying droop controllers with a gain-adaptive strategy. Besides to cope economically with uncertainty arise frequency excursions, a new, comfort-aware and versatile frequency dependent demand response program is mathematically formulated and conducted to the energy management system. It is aimed to co-optimize the microgrid energy resources such a way the day-ahead operational costs are managed subject to a secure frequency control portfolio. The presented model is solved using a two-stage stochastic programming and by a tractable efficient mixed integer linear programming approach. The simulation results are derived in 24-h scheduling time horizon and implemented on a typical test microgrid. The effectiveness of the proposed hourly gain assignment and frequency responsive load management program has been verified thoroughly by analyzing the results.

Abstract Objective Rapid, reliable, and affordable detection of Brucella species via the molecular methods remains a challenge. In recent years, loop-mediated isothermal amplification (LAMP) is a functional nucleic acid amplification technique offering a substitute to polymerase chain reaction (PCR). So, we compared the LAMP assay with the conventional PCR for the identification of common Brucella species in Iran. In this study, LAMP assay was comprehensively evaluated against the common PCR method. A group of specific LAMP primers were used to amplify a highly specific fragment from the sequence of the Brucella abortus, bcsp31 gene. Sensitivity and specificity values of tests were done with a set of 78 (50 Brucella and 28 non-Brucella) strains. Results A dilution series of B. abortus DNA indicated that the LAMP reaction could reliably detect 10 (fg/µl) DNA target copies per reaction within 36 min, which is 10 times greater than the PCR assay. In summary, we conclude that LAMP assay provide accurate and fast test results to identify of common Brucella species in low-complexity labs, mainly in low and lower middle income countries.

Objectives: The increasing crisis regarding multidrug-resistant (MDR) and extensively drug-resistant microorganisms leads to appealing therapeutic options. Methods: During the last 30 years, minocycline, a wide-spectrum antimicrobial agent, has been effective against MDR Gram-positive and Gram-negative bacterial infections. As with other tetracyclines, the mechanism of action of minocycline involves attaching to the bacterial 30S ribosomal subunit and preventing protein synthesis. Results: This antimicrobial agent has been approved for the treatment of acne vulgaris, some sexually transmitted diseases and rheumatoid arthritis. Although many reports have been published, there remains limited information regarding the prevalence, mechanism of resistance and clinical effectiveness of minocycline. Conclusion: Thus, we summarize here the currently available data concerning pharmacokinetics and pharmacodynamics, mechanism of action and resistance, antibacterial activity and clinical effectiveness of minocycline.

Background: The increasing resistance of human microbial pathogens to the available antibacterial compounds is a significant threat, resulting in the search for new antibiotic resources such as plants and probiotics. Therefore, this study aimed to evaluate the antibacterial effect of ethanolic and methanolic extracts of Urtica dioica, Mentha longifolia, and bacteriocin purified from a probiotic bacteria using the standard disk diffusion method against some pathogenic strains. Materials and methods: Ethanolic/methanolic extract of U. dioica, M. longifolia, and bacteriocin from probiotic bacteria were prepared by the standard methods. The effect of different concentrations of the extracts on some antibiotic-resistant bacteria was evaluated using the standard disk diffusion method by measuring the diameter of the growth inhibition zone. Results: The disk diffusion test showed that the bacteriocin Lactobacillus casei had more growth inhibitory effects on the tested bacterial strains than the methanolic and ethanolic extracts of U. dioica and M. longifolia. Bacteriocin extract of L. casei exhibited significant antibacterial activity at the concentrations of 12 and 18 mg/mL (P≤0.05) against antibiotic-resistant bacteria, while a 12 mm zone of inhibition was observed in the concentration of 1.5 mg/mL against Salmonella enterica serovar Typhimurium (S. Typhimurium). Conclusion: According to the agar well diffusion method results, the bacteriocin producing L. casei has an extensive range of antibacterial spectrum against resistant bacteria. It can be used as an alternative to antimicrobia agents for the treatment of infections caused by resistant bacteria. It is suggested that in future research, the cytotoxicity of the extracts be evaluated in vitro/in vivo studies.

ObjectivesInfections in the male genitourinary system with bacterial and viral agents may play a significant role in male infertility. These agents usually infect the urethra, seminal vesicles, prostate, epididymis, vas deferens, and testes retrograde through the reproductive system. A meta-analysis review study was performed to evaluate the presence of bacterial and viral agents in the semen of infertile men and its correlation with infertility.MethodsRelevant cross-sectional and/or case-control studies were found by an online review of national and international databases (Web of Science, PubMed, Scopus, Science Direct, and Google scholar), and suitable studies were selected. A checklist determined the qualities of all studies. Heterogeneity assay among the primary studies was evaluated by Cochran’s Q test and I2 index (significance level 50%). A statistical analysis was conducted using the Comprehensive Stata ver. 14 package (StataCorp, College Station, TX, United States).ResultsSeventy-two studies were included in this meta-analysis. Publication bias was compared with Egger’s test, and the impact of each research on overall estimate was evaluated by sensitivity analysis. In 56 studies, the rate of bacterial infections in the semen of infertile men was 12% [95% confidence interval (CI): 10–13]. Also, in 26 case-control studies, the association of infertility in men with bacterial infections was evaluated. The results show that the odds ratio of infertility in men exposed to bacterial infections is 3.31 times higher than that in non-infected men (95% CI: 2.60–4.23). Besides, in 9 studies that examined the prevalence of human papillomavirus (HPV), herpes simplex virus 1 (HSV1), herpes simplex virus 2 (HSV2), and herpes simplex virus 1-2 (HSV1-2) in infertile men, the frequency of these viruses was 15% (95% CI: 9–21). In 6 case-control studies, the association between human cytomegalovirus (HCMV), Cytomegalovirus (CMV), and HPV and male infertility was evaluated. The chance of male infertility due to exposure to these viruses was 2.24 times higher than those without exposure to these viruses (CI 95%: 1.9–4.52). The results show that the chance of infertility in men exposed to bacteria was significantly higher than that in the uninfected population.ConclusionThis meta-analysis showed that viral and bacterial infections are a risk factor and could impair male fertility potential. Moreover, our study supports the hypothesis that bacterial and viral infections of the genital tract correlate positively with impairment of sperm quality in the male population.

Abstract Background In several years ago, infection with human papillomaviruses (HPVs), have been prevalent in the worlds especially HPV type 18, can lead to cervical cancer. Therefore, rapid, accurate, and early diagnosis of HPV for successful treatment is essential. The present study describes the development of a selective and sensitive electrochemical biosensor base on DNA, for early detection of HPV-18. For this purpose, a nanocomposite of reduced graphene oxide (rGO) and multiwalled carbon nanotubes (MWCNTs) were electrodeposited on a screen-printed carbon electrode (SPCE). Then, Au nanoparticles (AuNPs) were dropped on a modified SPCE. Subsequently, single strand DNA (ssDNA) probe was immobilized on the modified electrode. The link attached between AuNPs and probe ssDNA provided by l-cysteine via functionalizing AuNPs (Cys-AuNPs). The differential pulse voltammetry (DPV) assay was also used to electrochemical measurement. The measurement was based on the oxidation signals of anthraquninone-2-sulfonic acid monohydrate sodium salt (AQMS) before and after hybridization between the probe and target DNA. Results The calibration curve showed a linear range between 0.01 fM to 0.01 nM with a limit of detection 0.05 fM. The results showed that the optimum concentration for DNA probe was 5 µM. The good performance of the proposed biosensor was achieved through hybridization of DNA probe-modified SPCE with extracted DNA from clinical samples. Conclusions According to the investigated results, this biosensor can be introduced as a proprietary, accurate, sensitive, and rapid diagnostic method of HPV 18 in the polymerase chain reaction (PCR) of real samples.

Background: Cancer is amongst the leading reasons of death in all parts of the world. Breast cancer is also responsible for the largest number of deaths among women population. Several studies confirmed that Bifidobacterium bifidum as a probiotic meaningfully inhibited breast cancer development. The present study aimed to investigate the effect of B. bifidum supernatant on the cell growth inhibition of the breast cancer 4T1 cell line, in vitro. Materials and methods: The present experimental work was conducted at Mazandaran University of Medical Sciences (MAZUMS), Sari, Iran. B. bifidum was cultured in the MRS broth at 37°C for 72 hours anaerobically and the B. bifidum supernatant (BS) was prepared by the freezing-thawing procedure. The cell growth inhibition of the probiotic strain was assessed using the MTT assay through breast cancer (4T1) cell line. Results: The results showed that the supernatant extracted from B.bifidum strain had good antiproliferative effects against 4T1 cancer cell line, compared to control group. The inhibitory effects growing with increased time. Conclusion: B. bifidum supernatant could be considered as a as potential probiotic candidates in the treatment of breast cancer. However, further in vitro/in vivo studies are required to complement our initial findings.

Introduction: Dental panoramic radiography (DPR) is one of the most frequent diagnostic X-ray procedures, the application of which is currently on a growing trend. During DPR, several radiosensitive tissues, such as the lens of the eyes, parotid gland, and thyroid gland, contribute to the radiation field, and it is necessary to monitor their received dose. The aim of this study was to evaluate the radiation dose to the lens of the eyes, parotid gland, and thyroid gland in patients undergoing DPR at Lorestan Province, Western Iran. Material and Methods: This cross-sectional study was performed on 180 patients of both genders referred to DPR at two most crowded hospitals in Khorramabad, Iran, namely Tamin-e Ejtemaei (TE) and Shohada-ye Ashayer (SA) hospitals. The radiation dose measurements were carried out using LiF (Mg, Cu, P) thermoluminescent dosimeters (TLDs). To measure the absorbed dose received by the lens of the eyes, parotid gland, and thyroid gland in each patient, five sets of three TLDs, wrapped in a thin plastic bag, were positioned over each eyelid and the anatomical position of the parotid and thyroid glands. The TLDs were read within 24 h of exposure. Results: The mean absorbed dose received by the lens of the eyes, parotid gland, and thyroid gland were obtained as 155, 160, and 72 µGy for the TE Hospital, respectively. These values were obtained as l24, 558, and 56 µGy, respectively, for the SA Hospital. The results revealed a statistically significant difference between the organs located outside and inside the primary beam in terms of the absorbed dose (PConclusion: The absorbed dose received by the lens of the eyes and thyroid gland was generally lower than the values reported in similar studies. Nevertheless, the absorbed dose received by the parotid gland in the SA Hospital exceeded the recommended dose reference level of 400 µGy in DPR.

Background: Probiotics are living organisms that are beneficial for human health. Lactobacillus species has been considered as probiotic bacteria due to their adjustment of human immune responses and therapeutic effects in inflammatory disorders. The aim of the present study was to evaluate the effects of Lactobacillus probiotic strains on toll-like receptors (TLR2 and TLR4) expression in HT29 cell line (a human colon cancer cell line) infected with S. enteritidis. Methods: This experimental study was done in Food Microbiology Research Center of Tehran University of Medical Sciences, Iran, from March 2016 to February 2017. In this study, two strains of Lactobacillus acidophilus PTCC 1643 and Lactobacillus casei PTCC 1608 were used. HT29 cells were cultured in RPMI medium containing fetal bovine serum and antibiotics. Then, the cells were treated with the Lactobacillus strains, after or before challenge with S. enteritidis. After total RNA extraction and cDNA synthesis, the capacity of probiotic lactobacilli to modulate TLR2 and TLR4 expression on treated and un-treated HT29 cells were assessed quantitatively using Real-time polymerase chain reaction technique with specific primers. Results: Our findings indicated that after treatment of non-infected HT29 cells, with both the probiotics, the expression of TLR2 and TLR4 genes significantly increased. In contrast, the expression of these two genes in HT29 cells which were infected with S. Enteritidis was significantly reduced before and after treatment with each one of the probiotic bacteria. The anti-inflammatory effect of probiotic lactobacilli on S. enteritidis were confirmed in tests. This study showed that L. acidophilus and L. casei play a major role in boosting the innate immune responses, the TLR2 and TLR4 expression levels also decreased, pre and post-infection with S. enteritidis. Conclusion: According to the results, both Lactobacillus strains have remarkable anti-inflammatory effect in pathogenicity of S. enteritidis, but L. acidophilus display greater anti-inflammatory activity than L. casei in this work. Additional in vivo and in vitro studies are required to further elucidate the mechanisms underlying this anti-inflammatory effect.

Objectives Genetic determinants conferring resistance to macrolide, lincosamide, and streptogramin B (MLSB) via ribosomal modification such as, erm, msrA/B and ereA/B genes are distributed in bacteria. The main goals of this work were to evaluate the dissemination of MLSB resistance phenotypes and genotypes in methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from clinical samples. Methods A total of 106 MRSA isolates were studied. Isolates were recovered from 3 hospitals in Tehran between May 2016 to July 2017. The prevalence of MLSB-resistant strains were determined by D-test, and then M-PCR was performed to identify genes encoding resistance to macrolides, lincosamides, and streptogramins in the tested isolates. Results The frequency of constitutive resistance MLSB, inducible resistance MLSB and MSB resistance were 56.2%, 22.9%, and 16.6%, respectively. Of 11 isolates with the inducible resistance MLSB phenotype, ermC, ermB, ermA and ereA were positive in 81.8%, 63.6%, 54.5% and 18.2% of these isolates, respectively. In isolates with the constitutive resistance MLSB phenotype, the prevalence of ermA, ermB, ermC, msrA, msrB, ereA and ereB were 25.9%, 18.5%, 44.4%, 0.0%, 0.0%, 11.1% and 0.0%, respectively. Conclusion Clindamycin is commonly administered in severe MRSA infections depending upon the antimicrobial susceptibility findings. This study showed that the D-test should be used as an obligatory method in routine disk diffusion assay to detect inducible clindamycin resistance in MRSA so that effective antibiotic treatment can be provided.

Abstract Transportation demand management (TDM) covers strategies for reducing traffic congestion within the affected urban areas. Congestion pricing includes a branch of TDM strategies; among them, the entry-based cordon pricing, i.e., applying charge on entry, is the most popular because of practicality and social acceptance. Many researchers have investigated different second-best approaches for evaluations of cordon pricing plans, mostly by applying static traffic assignment methods. In this paper, a joint entry- and distance-based scheme is proposed to circumvent the deficiencies intrinsic to each. The optimal joint design is considered as the solution to an optimization problem, in which an equilibrium dynamic traffic assignment model is used to take account of flow variations and represent congestion effects more realistically. The problem is solved for the network of Sioux Falls by using an enumeration algorithm, and the solution is compared with those obtained for distinct entry- and distance-based schemes. Based on the results, the joint tolling has the best performance in reducing the total travel time of the travelers and in alleviating the congestion level inside the cordoned area, while generating a higher level of revenue from tolls. Furthermore, the numerical experiments show the unreliability of the results by static against dynamic modeling approach.

Background & objective: Multidrug-resistant Acinetobacter baumannii (MDR-AB) is an important nosocomial pathogen which is associated with significant morbidity and mortality, particularly in high-risk populations. Aminoglycoside-modifying enzymes (AMEs) and 16S ribosomal RNA (16S rRNA) methylation are two important mechanisms of resistance to aminoglycosides. The aim of this study was to determine the prevalence of 16S rRNA methylase (armA, rmtA, rmtB, rmtC, and rmtD), and the AME genes [aac(6′)-Ib, aac(3)-I, ant(3′′)-I, aph(3′)-I and aac(6')-Id], among clinical isolates of A. baumannii in Tehran, Iran. Methods: Between November 2015 to July 2016, a total of 110 clinical strains of A. baumannii were isolated from patients in two teaching hospitals in Tehran, Iran. Antimicrobial susceptibility testing was performed according to Clinical and Laboratory Standards Institute guidelines. The presence of genes encoding the AMEs and16S rRNA methylases responsible for resis­tance was investigated by multiplex polymerase chain reaction. Results: The results showed that colistin was an effective antibiotic and could be used as a last-resort treatment of infections caused by MDR-AB. The resistance rate to aminoglycosides were 100%, 96.36% and 90.9% for tobramycin, gentamicin and amikacin, respectively. In this study, AME genes of aac(6′)-Ib, aac(3)-I and ant(3′′)-I were most prevalent among the isolated strains. Conclusion Markedly high resistance to tobramycin, gentamicin and amikacin was noted in current study. Our results suggested that modifying enzyme genes in conjunction with methylation of 16S rRNA might contribute to aminoglycoside resistance induced in vivo in A. baumannii.Further studies are required to determine the prevalence of the aminoglycoside resistance genes in other hospitals of Iran.

Introduction: Coronary angiography is the most common angiographic procedure for diagnosis and treatment of the heart diseases. Herein, we aimed to evaluate the entrance surface dose (ESD), dose area product (DAP), as well as cancer risk in interventional cardiology procedures. Materials and Methods: This study was conducted during July-December 2015 at Shahid Madani Heart Center in Khorramabad, Iran. A total of 225 adult patients including 122 females and 103 males regardless of the risk factors for coronary diseases were participated. Of them, 199 and 26 patients underwent diagnostic coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA), respectively. Each patient underwent CA or PTCA separately. All the procedures were carried out using Siemens angiography system with the pulsed fluoroscopy of 10-30 pulses/s and cine frame rate of 15 frames/s. DAP, ESD, fluoroscopy time (FT), as well as the number of sequences and frames per sequence were collected for each 199 CA and 26 PTCA procedures. Results: The median values of DAP were 19.77±14.88 and 57.11±33.36 Gy.cm2 in CA and PTCA, respectively. In addition, the median values of ESD were 323.12±245.39 and 1145.22±594.42 mGy in CA and PTCA, respectively. FTs were 114.59±74.33 s in CA and 424.15±292.93 s in PTCA. Conclusion: The average patient dose and cancer risk estimates in both CA and PTCA were consistent with the reference levels. However, in agreement with other interventional procedures, dose levels in the interventional cardiology are influenced by staff and clinical protocols, as well as the type of equipment.

This paper presents a new simple control strategy for direct driven PMSG wind turbines, using no wind speed sensor. There are several strategies for wind turbine control. Operation of different strategies in terms of power smoothing is compared. New strategy is proposed to have more power smoothing. Performance of the proposed strategy is evaluated by MATLAB/ Simulink simulations and its validity and effectiveness are verified.

Background: Anode heel effect refers to reduction of radiation intensity in the anode side of X-ray tube. This variation in radiation intensity across the anode-cathode of X-ray tube can be benefited for decrease radiation exposure in some radiological examinations. The aim of this study was to evaluate the effect of anode heel orientation on the radiation dose received by the testes in male patients undergoing pelvic radiography. Methods: This is a cross-sectional study, conducted at one of the teaching hospitals of Ahvaz, Jundishapur University of Medical Science Ahvaz, Iran, from September 2015 to March 2016. In order to measure the profile of radiation intensity variation, 13 paired sets of high radiosensitive cylindrical lithium fluoride thermo-luminescent dosimeters (TLD) aligned on the cathode-anode central axis upon the table and then irradiated using routine exposure parameters. The anode of X-ray tube was positioned toward the feet for 40 patients and toward the head for 39 patients undergoing pelvic radiography. For measure the entrance skin dose (ESD), 8 TLD chips were located on the central point of the radiation field and 5 TLDs were located on the testes position to measure the dose received. Results: Radiation intensity profile showed that radiation intensity decrease from the cathode to the anode side. Discrepancy of radiation intensity on central axis of cathode-anode was calculated about 35%. The radiation dose received by the testes was 26.74% lower for patients the anode directed toward the feet, compared to the patients in which the anode directed toward the head (FTC: 1.260±0.296 mGy, FTA: 0.923±0.167 mGy, P

Introduction Radioactive materials naturally exist in the world. Indeed, approximately 82% of human-absorbed radiation doses, which are out of human control, arise from natural sources of radiation including cosmic, terrestrial, and exposure through inhalation or ingestion. Thus, the aim of the present study was to estimate health risk, as well as the effective and organ doses from naturally occurring background radiation in residents living in the vicinity of Khorramabad, Iran. Materials and Methods This cross-sectional study was carried out in Khorramabad, Iran. The measurements were performed using Geiger-Muller detector (RDS-110) during daylight from April to June, 2015. The natural gamma radiation measurements were made both indoor and outdoor across five regions of Khorramabad (north, south, west, east, and center). Results The estimated mean absorbed dose rate in outdoor and indoor zones were 0.09±0.024 and 0.117±0.032 mSvy-1, respectively. Additionally, the mean annual effective dose was calculated as 0.69±0.19 mSvy-1, while the estimated health risk probability was 0.0345%. Conclusion The average annual effective dose arising from gamma background radiation was higher than global values. Therefore, more studies are required to examine the relationship between radiation-induced effects and the natural background radiation level in Khorramabad.

Introduction High intensity focused ultrasound (HIFU) is considered a noninvasive and effective technique for tumor ablation. Frequency and acoustic power are the most effective parameters for temperature distribution and the extent of tissue damage. The aim of this study was to optimize the operating transducer parameters such as frequency and input power in order to acquire suitable temperature and thermal dose distribution in the course of a numerical assessment. Materials and Methods To model the sound propagation, the Khokhlov-Zabolotskava-Kuznetsov (KZK) nonlinear wave equation was used and simulation was carried out using MATLAB HIFU toolbox. Bioheat equation was applied to calculate the transient temperature in the liver tissue. Frequency ranges of 2, 3, 4, and 5 MHz and power levels of 50 and 100 W were applied using an extracorporeal transducer. Results Using a frequency of 2 MHz, the maximum temperatures reached 53°C and 90°C in the focal point for power levels of 50 W and 100 W, respectively. With the same powers and using a frequency of 3 MHz, the temperature reached to 71°C and 170°C, respectively. In addition, for these power levels at the frequency of 4 MHz, the temperature reached to 72°C and 145°C, respectively. However, at the 5 MHz frequency, the temperature in the focal spot was either 57°C or 79°C. Conclusion Use of frequency of 2 MHz and power of 100 W led to higher thermal dose distribution, and subsequently, reduction of the treatment duration and complications at the same exposure time in ablation of large tumors.

Background: Neisseria meningitidis, a life-threatening human pathogen with the potential to cause large epidemics, can be isolated from the nasopharynx of 5–15% of adults. The aim of the current study was to evaluate biophysical and biochemical properties and immunological aspects of chimeric acyl-carrier protein-macrophage infectivity potentiator protein-type IV pilus biogenesis protein antigen (ACP-MIP-PilQ) from N. meningitidis serogroup B strain. Methods: Biochemical properties and multiple alignments were predicted by appropriate web servers. Secondary molecular structures were predicted based on Chou and Fasman, Garnier-Osguthorpe-Robson, and Neural Network methods. Tertiary modeling elucidated conformational properties of the chimeric protein. Proteasome cleavage and transporter associated with antigen processing (TAP) binding sites, and T- and B-cell antigenic epitopes, were predicted using bioinformatic web servers. Results: Based on our in silico and immunoinformatics analyses, the ACP-MIP-PilQ protein (AMP) can induce high-level cross-strain bactericidal activity. In addition, several immune proteasomal cleavage sites were detected. The 22 epitopes associated with MHC class I and class II (DR) alleles were confirmed in the AMP. Thirty linear B-cell epitopes as antigenic regions were predicted from the full-length protein. Conclusion: All predicted properties of the AMP indicate it could be a good candidate for further immunological in vitro and in vivo studies.

Background: Sigma factors are proteins that regulate transcription in bacteria. Sigma factors can be activated in response to different environmental conditions. The rpoS (RNA polymerase, sigma S) gene encodes sigma-38 (σ38, or RpoS), a 37.8 kDa protein in Pseudomonas aeruginosa (P. aeruginosa) strains. RpoS is a central regulator of the general stress response and operates in both retroactive and proactive manners; not only does it allow the cell to survive environmental challenges; it also prepares the cell for subsequent stresses (cross-protection). Methods: The significance of RpoS for stress resistance and protein expression in stationary-phase P. aeruginosa cells was assessed. The goal of the current study was to characterize RpoS of P. aeruginosa PAO1 using bioinformatics tools. Results: The results showed that RpoS is an unstable protein that belongs to the sigma-70 factor family. Secondary structure analysis predicted that random coil is the predominant structure followed by extended alpha helix. The three-dimensional (3D) structure was modeled using SWISS-MODEL Workspace. Conclusion: Determination of sequence, function, structure, and predicted epitopes of RpoS is important for modeling of inhibitors that will help in the design of new drugs to combat multi-drug-resistant (MDR) strains. Such information may aid in the development of new diagnostic tools, drugs, and vaccines for treatment in endemic regions.

Introduction In radiography, dose and image quality are dependent on radiographic parameters. The problem is caused from incorrect use of radiography equipment and from the radiation exposure to patients much more than required. Therefore, the aim of this study was to implement a quality-control program to detect changes in exposure parameters, which may affect diagnosis or patient radiation dose. Materials and Methods This cross-sectional study was performed on seven stationary X-ray units in sixhospitals of Lorestan province. The measurements were performed, using a factory-calibrated Barracuda dosimeter (model: SE-43137). Results According to the results, the highest output was obtained in A Hospital (M1 device), ranging from 107×10-3 to 147×10-3 mGy/mAs. The evaluation of tube voltage accuracy showed a deviation from the standard value, which ranged between 0.81% (M1 device) and 17.94% (M2 device) at A Hospital. The deviation ranges at other hospitals were as follows: 0.30-27.52% in B Hospital (the highest in this study), 8.11-20.34% in C Hospital, 1.68-2.58% in D Hospital, 0.90-2.42% in E Hospital and 0.10-1.63% in F Hospital. The evaluation of exposure time accuracy showed that E, C, D and A (M2 device) hospitals complied with the requirements (allowing a deviation of ±5%), whereas A (M1 device), F and B hospitals exceeded the permitted limit. Conclusion The results of this study showed that old X-ray equipments with poor or no maintenance are probably the main sources of reducing radiographic image quality and increasing patient radiation dose.

Successful implementation of knowledge management fororganizations requires a systematic and comprehensive perspective aboutvarious organizational factors. Appropriateness of these factors and theirintegration and coordination is a vital perquisite for implementingknowledge management effectively. The primary purpose of the researchis investigating the effect of three fundamental aspects of intellectualcapital– human capital, structural capital and relational capital– on fourstages of knowledge management practices (knowledge creation, storage,application and sharing). The data collection instrument is questionnaireand the research method is descriptive and corelational. The populationstudied in the research consists of managers and senior experts of thegovernment state of one of the south states of Iran. A sample of 120subjects was selected by simple random sampling. Data obtained isanalyzed using correlation coefficient method and structural equationsmodeling. According to the research findings there are significantrelationships between these intellectual assets and knowledgemanagement practices. These findings support the necessity of preparingthe perquisites of effective implementation of knowledge management.Accordingly, an organization characterized by more developedintellectual capitals can benefit from knowledge management initiatives.

Background & Objectives: Helicobacter pylori (Hp) is related to gastritis, gastric ulcer, duodenal ulcer, and mucosal carcinoma. Emergence of multidrug resistant Hp strains encouraged the researchers to find new effective drugs. Especially medicinal herbs and plants which usually shows less side effects. The aim of this study was in vitro assessment of anti Hp activity of total extract of Tribulus terrestris (T. terrestris Benzoxacin, a local Iranian medicinal plant and its fraction Benzoxacin.Methods: total aqueous extract of aerial parts of the plant was prepared and liquid extraction with petroleum ether was used to separate its components. LC/MS system proved the existence of Benzoxazine derivative in the water fraction and the third's fraction. Anti (Hp) effects of total extract and its third fraction were examined by cup plate method and using standard MacFarland. 50 biopsy samples of antrum were detected from patients who were endoscopic candidates in Milad and Fayazbakhsh hospitals of Tehran during 2011. All samples were isolated, diagnosed based on standard methods and biochemical tests and confirmed by PCR method for ureC gene, too. Different dilutions (250, 500,750 and 1000 mg/ml) of total extract were prepared. Clarythromycin (Clr) E-test strips and an identified Hp OC1096 was used, simultaneously.Results: Of 50 biopsy samples, 12 Hp strains were isolated. Rapid urease test were positive in all expect one biopsy sample. Existence of ureC gene in all isolates were confirmed expect one strain by PCR. By cup plate method, resistant to concentrations of 1000 and 750mg/ml were detected in 50% of Hp isolates and 66.6% of them were resistant to concentrations 250 and 500 mg/ml .Also, 83.3% of Hp strains were resistant to Benzoxacin fraction. Clarythromycin sensitivity detected in 83% of Hp isolates, simultaneously.Conclusion: This study was done as a pilot study for in vitro evaluation of antibacterial effect of total extract of T. terrestris by cup plate method. Existence of high resistant rate (≥50%) to different concentrations T. terrestris aqueous extract seems doing test on more Hp strains in future studies is highly recommended . In contrast of the similarity of Benzoxazin structure to Ofloxacin, existence of 83.3% of resistance among tested isolates showed no anti Hp effectiveness of this fraction.

In the knowledge-based era, knowledge is considered the most influential asset of successful organizations and knowledge management (KM) is their most important function. Knowledge creation is one of the most important practices of KM and has an influential effect on the innovativeness of organization. Knowledge creation is considerably dependent on the employees’ capabilities and readiness. Employees’ empowerment can develop these capabilities effectively. Accordingly, the purpose of this paper is to describe the effects of empowering of employees on the knowledge creation by them. The research method is descriptive and correlational. The population of the research consists of 950 managers and senior experts of the NIOPDC. A sample of 270.subjects was selected as statistical sampling. According to the research findings, all of the studied psychological dimensions of employees' empowerment have positive considerable effects on enhancing knowledge creation in organization. Finally, according to research findings, some suggestions are presented.

Successful implementation of an executive information system (EIS) is not an easy job for most of organizations. Out of many factors to be considered, the success or failure of an EIS ultimately depends on how well the implementation process is managed in terms of both technology and users. This article with regarding to senior managers’ information needs to make strategic decisions, was about to recognize critical success factors in implementing EIS in the Iranian organizations. Statistical Population in this research included managers and experts in Petroleum Equipment Industries Corporation (PEIC) and its subordinates. A questionnaire was developed by researchers for gathering data from sample population. Research findings based on factor analysis was indicative of following critical success factors for implementation of EIS: 1) Development of an appropriate conceptual model; 2) a participative approach in design and development; 3) a relevant technology; 4) role of IT Department; 5) project management of EIS; 6) supportive role of senior management; and 7) software capabilities. The model explained 59 percent of the variance in successful implementation of EIS. Therefore, it should be bear in mind that there are others CSFs which were not recognized in this research.

Generally, in a waveguide-based humidity sensors, increasing the relative humidity (RH) causes the cladding refractive index (RI) to increase due to cladding water absorption. However, if graphene oxide (GO) is used, a reverse phenomenon is seen due to a gap increase in graphene layers. In this paper, this interesting property is applied in order to fabricate differential humidity sensor using the difference between RI of reduced GO (rGO) and nano-anatase TiO2 in a chip. First, a new approach is proposed to prepare high quality nano-anatase TiO2 in solution form making the fabrication process simple and straightforward. Then, the resulted solutions (TiO2 and GO) are effortlessly drop casted and reduced on SU8 two channels waveguide and extensively examined against several humid conditions. Investigating the sensitivity and performance (response time) of the device, reveals a great linearity in a wide range of RH (35% to 98%) and a variation of more than 30 dB in transmitted optical power with a response time of only ~0.7 sec. The effect of coating concentration and UV treatment are studied on the performance and repeatability of the sensor and the attributed mechanisms explained. In addition, we report that using the current approach, devices with high sensitivity and very low response time of only 0.3 sec can be fabricated. Also, the proposed device was comprehensively compared with other state of the art proposed sensors in the literature and the results were promising. Since high sensitivity ~0.47dB/%RH and high dynamic performances were demonstrated, this sensor is a proper choice for biomedical applications.

Purpose: Dosimetry is an integral part of radiotherapy and dose verification is one of the important stages in modern radiotherapy. Nowadays gel dosimeters are the only dosimeters that can record dose distribution in three dimensions only with a single measurement. The purpose of this study was to evaluate the capability of polymer gel dosimetry in dose verification of compensator-based IMRT. Methods: A cerrobend slab with 4 cm thickness was manufactured and percentage depth dose curves for 18 MV photon beam and 10×10 cm2 field size were obtained by ionization chamber and polymer gel dosimeter. Then, an anthropomorphic pelvic phantom with gel inserts was constructed and irradiated with compensator-based IMRT technique. Results: A comparison of the result of dose measurements with ion chamber and gel dosimeter showed that in spite of changing mean beam quality, compensators have no effect on response of gel dosimeter. Besides, according to distance to agreement (DTA) analysis there was good agreement between calculated and gel measured dose distributions. Conclusion: The methodology presented in this work proved the feasibility of polymer gel dosimeter as an ideal tool for pretreatment IMRT QA and also the constructed phantom can be used efficiently in other radiotherapy techniques. Future works will be focused on the development of lung equivalent polymer gel dosimeter.

An on-chip optical humidity sensor using Nano-anatase TiO2 coating is presented here. The coating material was prepared so that the result is in solution form, making the fabrication process quick and simple. Then, the solution was effortlessly spin-coated on an SU8 straight channel waveguide. Investigating the sensitivity and performance (response time) of the device revealed a great linearity in the wide range (35% to 98%) of relative humidity (RH). In addition, a variation of more than 14 dB in transmitted optical power was observed, with a response time of only ~0.7 s. The effect of coating concentration and UV treatment was examined on the performance and repeatability of the sensor. Interesting observations were found, and the attributed mechanisms were described. In addition, the proposed sensor was extensively compared with other state-of-the-art proposed counterparts from the literature and remarkable advantages were found. Since a high sensitivity of ~0.21 dB/%RH and high dynamic performances were demonstrated, this sensor is proposed for use in biomedical applications.

Background: On account of the lower electron density in the lung tissue, the dose distribution in the lung cannot be verified with the existing polymer gel dosimeters. Thus, the aims of this study are to make a low density polymer gel dosimeter and investigate the effect of nitrogen gas bubbles on the R 2 responses and its homogeneity. Materials and Methods: Two different types of low density polymer gel dosimeters were prepared according to a composition proposed by De Deene, with some modifications. In the first type, no nitrogen gas was perfused through the gel solution and water. In the second type, to expel the dissolved oxygen, nitrogen gas was perfused through the water and gel solution. The post-irradiation times in the gels were 24 and 5 hours, respectively, with and without perfusion of nitrogen gas through the water and gel solution. Results: In the first type of gel, there was a linear correlation between the doses and R 2 responses from 0 to 12 Gy. The fabricated gel had a higher dynamic range than the other low density polymer gel dosimeter; but its background R 2 response was higher. In the second type, no difference in R 2 response was seen in the dose ranges from 0 to 18 Gy. Both gels had a mass density between 0.35 and 0.45 g.cm -3 and CT values of about -650 to -750 Hounsfield units. Conclusion: It appeared that reactions between gelatin-free radicals and monomers, due to an increase in the gel temperature during rotation in the household mixer, led to a higher R 2 -background response. In the second type of gel, it seemed that the collapse of the nitrogen bubbles was the main factor that affected the R 2 -responses.

The world is naturally radioactive and approximately 82% of human-absorbed radiation doses, which are out of control, arise from natural sources such as cosmic, terrestrial, and exposure from inhalation or intake radiation sources. In recent years, several international studies have been carried out, which have reported different values regarding the effect of background radiation on human health. Gamma radiation emitted from natural sources (background radiation) is largely due to primordial radionuclides, mainly 232 Th and 238 U series, and their decay products, as well as 40 K, which exist at trace levels in the earth′s crust. Their concentrations in soil, sands, and rocks depend on the local geology of each region in the world. Naturally occurring radioactive materials generally contain terrestrial-origin radionuclides, left over since the creation of the earth. In addition, the existence of some springs and quarries increases the dose rate of background radiation in some regions that are known as high level background radiation regions. The type of building materials used in houses can also affect the dose rate of background radiations. The present review article was carried out to consider all of the natural radiations, including cosmic, terrestrial, and food radiation.