Digital twin-based fault tolerance approach for Cyber-Physical Production System.

Cyber-Physical Production Systems (CPPSs) as distributed Systems of Systems (SoS) are at the center of attention from different industries. CPPSs face different categories of errors. These errors will cause failures of the entire production chain. To handle this concern, production systems should be converted into fault-tolerant production systems. To present such systems, a fault tolerance approach was developed to help possible faults prediction and detection of faults causes in this study. Also, the increasing complexity and uncertainty of CPPS call for Digital Twin (DT)-based fault tolerance approach. The proposes approach uses an extraction module to extract the faults signatures efficiently. Based on all extracted faults, appropriate responses could be generated through reliable faults patterns prediction. This method is provided using Fault Tree Analyzer (FTA), Zero-suppressed Decision Diagram (ZDD), and Support Vector Machine-Adaptive Neuro-Fuzzy Inference System (SVM-ANFIS) structure. The results based on digital twin-based CPPS of the food production system as a use case show that the proposed approach can predict reliable faults signatures to prevent failures and make a much reliable production system. Also, this method can guarantee that CPPS is up and running with optimal levels at all times.

What Left for Us for Urinary Tract Infection Treatment? An Experience from the South of Iran.

BACKGROUND: The aim of the study is to define the prevalence and antimicrobial susceptibility pattern of bacteria from cases of urinary tract infections (UTIs). MATERIALS AND METHODS: A retrospective analysis of urinary pathogens and their antimicrobial susceptibility was done on urine cultures at Shiraz University Laboratory from 2015 to 2017. Antimicrobial susceptibility tests have done using the disk-diffusion technique as per the standard of CSLI. RESULTS: During 2 years of study, 3489 samples were culture positive. Escherichia coli was the dominant isolate (84%), followed by Klebsiella spp. (10.7%) and Enterococci spp. (2,2%). The overall resistance rates to trimethoprim-sulfamethoxazole, ceftriaxone, and ciprofloxacin were 56.1%, 47.2%, and 37%, respectively. The most frequently isolated bacteria were E. coli, which had resistance rates of 58.6%, 49.1% to TMP-STX, and cefixime, also sensitivity rates of 95.1% to nitrofurantoin (FM). CONCLUSIONS: In the study area, resistance rates to fluoroquinolones and cephalosporins were high. Because most isolates were sensitive to FM and aminoglycoside, they are suggested as appropriate antimicrobials for empirical treatment of UTIs before available urine culture results.

Toward high degree flexible routing in collision-free FMSs through automated guided vehicles' dynamic strategy: A simulation metamodel.

The present study proposes a simulation-based model of high degree flexible routing to prevent collisions and deadlocks in flexible manufacturing systems (FMSs). High degree flexible routing concurrently involves classical routing strategies (specifies the destination and static/dynamic routing between origin and destination) with routing flexibility (considers alternatives to select as destination). A new approach named Tandem-Queue-Link with a look-ahead (TQL-A) is proposed in which the look-ahead mechanism supports deadlock prevention. The TQL-A performs a collision-free status for automated guided vehicles (AGVs) routing with flexible dynamic strategy. The main contribution of the present study is to implement the routing flexible levels (RFLs) by dynamic flexible routing (DFR) as a high degree flexible routing strategy. The most efficient parameters of this highly complex FMS are designed using a multi-objective nonlinear programming model extracted from simulation metamodels based on different hypotheses. Results support some of the considered hypotheses and show the complicated relationship between different values of FMS design parameters and different levels of routing flexibility. Metamodel validity through a typical case study defines that the higher values of velocity and acceleration/deceleration can compensate the level of routing flexibility but other parameters that are influenced by the active parameter (i.e. those related to loading/unloading time) have not any sensible influence on the output.

Antibiotic susceptibility pattern and identification of extended spectrum ß-lactamases (ESBLs) in clinical isolates of Klebsiella pneumoniae from Shiraz, Iran.

BACKGROUND AND OBJECTIVES: Klebsiella pneumoniae, one of the important causes of nosocomial infections, is the most common extended spectrum ß-lactamases (ESBLs) producing organism. ESBLs are defined as the enzymes capable of hydrolyzing oxyimino-cephalosporins, monobactams and carbapenems. The aims of this study were to identify ESBL-producing K. pneumoniae isolates and detect their antibiotic susceptibility pattern. MATERIALS AND METHODS: This cross-sectional study was conducted from December 2012 to May 2013 in teaching hospitals in Shiraz. Clinical specimens from the urine, sputum, wound, blood, throat, and body fluids were isolated and identified as K. pneumoniae. Antibacterial susceptibility testing was performed for 14 antibiotics using disk diffusion method according to CLSI guidelines. Isolates showing resistant to at least one of the ß-lactam antibiotics were then evaluated for production of ß-lactamase enzymes using E-test ESBL and combined disk Method. Also, MICs for ceftazidime and imipenem were determined using E-test. The presence of the bla SHV, bla TEM, bla PER and bla CTX-M genes was assessed by PCR. RESULTS: Of 144 K. pneumoniae isolates from different specimens, 38 (26.3 %) was identified as ESBL producer by phenotypic confirmatory test. All ESBL producing isolates were susceptible to imipenem and meropenem and resistant to aztreonam. The highest rate of resistance belonged to amoxicillin (100%), cefotaxime (50%) and gentamicin (42.3%) and the lowest rates were seen for meropenem (11.8%), imipenem and amikacin (both 15.9%). Sixty-two isolates had MICs≥ 4 µg/mL for ceftazidime, of which 38 were positive for ESBLs in phenotypic confirmatory tests (PCT). The prevalence of bla SHV, bla CTX-M, and bla TEM genes among these isolates were 22.2%, 19% and 16%. bla PER was not detected in the studied isolates. CONCLUSIONS: Due to the relatively high prevalence of ESBLs-producing K. pneumoniae isolates in the studied population, it seems that screening of infections caused by ESBL producers can lead to the most effective antibiotics therapies.

Genetic polymorphisms of glutathione-s-transferase M1 and T1 genes with risk of diabetic retinopathy in Iranian population.

OBJECTIVES: To the best of our knowledge, this is the first report on the contributions of GST genetic variants to the risk of diabetic retinopathy in an Iranian population. Therefore, the objective of this study was to determine whether sequence variation in glutathione S-transferase gene (GSTM1 and GSTT1) is associated with development of diabetic retinopathy in type 2 diabetes mellitus (T2DM) Iranian patients. MATERIALS AND METHODS: A total of 605 subjects were investigated in this case-control study; Study groups consisted of 201 patients with diabetic retinopathy (DR), 203 subjects with no clinically significant signs of DR and a group of 201 cases of healthy volunteers with no clinical evidence of diabetes mellitus or any other diseases. The GSTM1 and GSTT1 were genotyped by multiplex-polymerase chain reaction (multiplex-PCR) analysis in all 404 T2DM patients and 201 healthy individuals served as control. RESULTS: Increased odds ratio showed that GSTM1-null genotype had a moderately higher occurrence in T2DM patients (OR=1.43, 95% CI=1.01-2.04; P=0.03) than in healthy individuals. However, the frequency of GSTT1 genotype (OR=1.41; 95% CI=0.92-2.18; P=0.09) was not significantly different comparing both groups. Although, regression analysis in T2DM patients showed that GSTM1 and GSTT1 genotypes are not associated with T2DM retinopathy development. CONCLUSION: Our findings suggest that GSTM1 and GSTT1 genotypes might not be involved in the pathogenesis of type 2 diabetes mellitus retinopathy in the Southern Iranian population. However, further investigations are needed to confirm these results in other larger populations.

Cytologic findings of a pleomorphic adenoma of the breast: a case report.

BACKGROUND: Pleomorphic adenoma of the breast is a rare benign tumor. Only a few cases have been reported. The histologic features have been described well. However, the cytologic findings have been described in only a few papers. CASE: A 47-year-old female presented with a left breast mass of several months' duration. The clinical and mammographic findings were highly suspicious for malignancy. Following an aspiration biopsy diagnosis of "positive for malignancy," the mass was excised. The histologic diagnosis was pleomorphic adenoma (mixed tumor of salivary gland type) rather than carcinoma. CONCLUSION: The cytologic presentation of pleomorphic adenoma of the breast can masquerade as that of a malignant tumor, in this case colloid carcinoma. This case delineates the cytomorphologicfeatures of pleomorphic adenoma, which may mimic carcinoma.