Mobility and Dispersion Optimization of Nano Zerovalent Iron (nZVI) in Disinfection of Urban Wastewater with Pneumatic Nitrogen Gas Injection

Zero iron nanoparticle is considered as a universal enhancement agent. Its stabilization in aqueous environments with different coatings, reduces the efficiency of nanoparticles to a great extent. This study aimed to optimize the mobility and dispersion of nanoparticles to increase the inactivation efficiency of heterotrophic bacteria in urban sewage effluents. The experiment was carried out on Response Surface Methodology (RSM) and Central Composite Design (CCD) using Design Expert 10 software. Iron nanoparticles were synthesized in two types of carboxymethyl cellulose-coated and simple type. B-nZVI  was introduced into the effluent with by pneumatic injection of nitrogen gas. CMC-nZVI was also mixed with a mixer in the effluent. Comparison of the results was done with two HPC and cellular molecular techniques (Genetic sequencing of 16s rRNA bacteria). The highest inactivation efficiency (90%) was observed in minute 23 for pneumonic injection of B-nZVI at a flow rate of 10 L / min.  Finally, with the improvement of gas pressure and flow rate, the inactivation efficiency was recorded at 95.6% at 32 minutes. Final model obtained from this process agreed with the quadratic equation. General forecasting of the model was expressed by the correlation coefficient (R2=0.9447) that made good fitness for the response data. The statistical significance was determined using Fisher's statistics (F-value=13.29). For optimal use of nZVI in the inactivation of urban wastewater heterotrophic bacteria, nZVI can be injected into the wastewater by pneumatic injection in two steps with an inert gas such as nitrogen. In the nZVI pneumatic injection, the efficiency of deactivating bacteria in urban wastewater treatment plants was about 17% to 39% better than that of the coated-nZVI such as CMCs

A bispectral index guided comparison of target-controlled versus manually-controlled infusion of propofol and remifentanil for attenuation of pressor response to laryngoscopy and tracheal intubation in non cardiac surgery

BACKGROUND: Target-controlled infusion is a new delivery system for intravenous anesthetic agents with which the anesthetist targets a plasma or effect-site drug concentration to achieve a predetermined effect. With this system, the tedious task of calculating the amount of administered drug required to achieve the target concentration is left in charge of a microprocessor which commands the infusion device. In this prospective study we compared alterations in blood pressure and heart rate from initiation of induction of anesthesia until 3 minutes after tracheal intubation in two methods of drug infusion, target-controlled infusion (TCI) and manually controlled infusion (MCI). Total anesthetic drug used until 3 minutes after intubation and level of produced hypnosis also were compared between two methods.
 METHODS: 40 patients were enrolled in this clinical trial study and were allocated randomly in two groups, each group consisting of 20 patients. In TCI group, patients received propofol and remifentanil with TCI pump to achieve 7 µg/ml and 4 ng/ml as plasmatic target drug levels, respectively. In MCI group, patients received propofol 2 mg/kg and remifentanil 1 µg/kg of body weight with manually controlled infusion. Both groups received succinylcholine as muscle relaxant to facilitate laryngoscopy and tracheal intubation. Bispectral index (BIS) was passively recorded in two groups to compare the level of hypnosis. Blood pressure (BP) and heart rate (HR) were recorded at 5 different times (T-1, T0, T1, T2 and T3). Independent t-test and paired t-test were used for data analysis.
 RESULTS: Systolic arterial pressure (SAP) was not different at T-1 between two groups but systolic hypotension was seen in MCI group more than TCI group at T0 (P<0.05). Systolic hypertension was more common in MCI group after intubation; i.e. SAP showed significant differences in T1, T2 and T3 between two groups (P<0.05). Mean arterial pressure (MAP) showed significant difference only at T0 and T1 between two groups. Also, heart rate in MCI group was higher than that in TCI group at T1 and T2. Mean used propofol was 128.10 ± 11.30 mg in MCI group versus 140.90 ± 16.21 mg in TCI group (P<0.05) and the least BIS value recorded was 31.4 ± 10 in MCI group versus 42.5 ± 12.3 in TCI group (P<0.05). 
 CONCLUSIONS: Hypotension in MCI group was seen more frequently than that in TCI group after induction and before laryngoscopy (T0). Hypertension and tachycardia were seen in MCI group more commonly than those in TCI group after laryngoscopy and tracheal intubation. Then, we recommend TCI technique in high risk patients for attenuation of the pressor response to laryngoscopy and tracheal intubation. Also, we recommend further researches in other educational centers to compare the effect-site TCI with plasmatic TCI in controlling pressor response.
 KEY WORDS: Anesthetic techniques, intravenous infusion, target-controlled infusion, propofol, remifentanil, bispectral index

Comparison of target-controlled infusion of sufentanil and remifentanil in blunting hemodynamic response to tracheal intubation

BACKGROUND: Maintaining blood pressure (BP) and heart rate (HR) after laryngoscopy and tracheal intubation has always been a concern in injured patients. Opioids can attenuate or stop an increase in these two parameters if administered with proper doses or targets in target-controlled infusion (TCI). Remifentanil and sufentanil are widely used for this purpose because their cardiac side effects are low and, especially in traumatic patients, they are tolerated well. A comparison of the benefits and limitations of these two opioids in TCI is much needed. A literature review in electronic data bases revealed few results. METHODS: 40 normotensive patients were enrolled to this randomized clinical trial study. After BIS guided anesthesia with a target-controlled propofol infusion and muscle relaxation with cisatracurium, remifentanil and sufentanil were infused using TCI with 2 and 0.2 ng.ml-1 targets respectively. BP and HR were recorded for five data points and compared with Fischer's exact test. RESULTS: Systolic, mean and diastolic arterial pressure and HR in different points of the study remained below baseline values but were out of control in some cases, however the out-of-control values showed significant difference between the two groups only for heart rate changes. The relative risk for producing out-of-control changes with remifentanil compared to sufentanil is significantly more than 1 for HR decrease. CONCLUSIONS: Sufentanil produced more common pre-intubation hypotension than remifentanil in propofol anesthetized patients but this hypotension disappeared sooner than remifentanil after tracheal intubation. Both opioids prevent an increase in BP and HR after tracheal intubation but the side effects (hypotension and bradycardia) may be a cause for concern (IRCT138710011361N

Machine learning prediction of wave characteristics : comparison between semi-empirical approaches and DT model

Prediction of wave characteristics plays a crucial role in design and performance assessment of various coastal projects. The computational complexity and time-consuming procedures have limited the applications of numerical models for wave predictions. This study develops a new model for wave prediction using the capabilities of the M5p Decision Tree (DT) algorithm. The wind speed was employed as the model input parameter, and satellite measured altimeter data was used to train and test the developed models. The proposed DT-based model is compared with the existing semi-empirical wave prediction methods recommended by Coastal Engineering Manual (CEM). For a comprehensive assessment of the model's performance, four scenarios with different input data and modelling approaches are investigated. It was shown that the locally calibrated CEM formula can provide the best performance amongst the modified semi-empirical formulations. Comparison results show that M5p DT models' prediction are far more accurate and closely match the satellite measured altimeter data than the semi-empirical models. Furthermore, the ‘Short-term’ M5p tree model is shown to have the best predictive results, and the obtained results highlight that the proposed M5p model can provide a robust alternative for wave prediction across large spatial and temporal scales

Machine learning as a downscaling approach for prediction of wind characteristics under future climate change scenarios

Assessment of climate change impacts on wind characteristics is crucial for the design, operation, and maintenance of coastal and offshore infrastructures. In the present study, the Model Output Statistics (MOS) method was used to downscale a Coupled Model Intercomparison Project Phase 5 (CMIP5) with General Circulation Model (GCM) results for a case study in the North Atlantic Ocean, and a supervised machine learning method (M5’ Decision Tree model) was developed for the first time to establish a statistical relationship between predicator and predicant. To do so, the GCM simulation results and altimeter remote sensing data were employed to examine the capabilities of the M5’DT model in predicting future wind speed and identifying spatiotemporal trends in wind characteristics. For this purpose, three classes of M5′ models were developed to study the annual, seasonal, and monthly variations of wind characteristics. The developed decision tree (DT) models were employed to statistically downscale the Beijing Normal University Earth System Model (BNU-ESM) global climate model output. The M5′ models are calibrated and successfully validated against the GCM simulation results and altimeter remote sensing data. All the proposed models showed firm outputs in the training section. Predictions from the monthly model with a 70/30 training to test ratio demonstrated the best model performance. The monthly prediction model highlighted the decreasing trend in wind speed relative to the control period in 2030 to 2040 for the case study location and across all three future climate change scenarios tested within this study. This reduction in wind speed reduces wind energy by 13% to 19%

Association of Integrons with Multidrug-Resistant Isolates among Phylogenic Groups of Uropathogenic Escherichia Coli

The aims of this study were to investigate the antibiotics susceptibility, multidrug- resistant (MDR) frequency and the association of integrons with MDR among phylogenic groups of uropathogenic E. coli (UPEC). In total, 176 non-duplicated UPEC isolates were collected from urinary tract infections (UTIs) specimens. The disk diffusion method was performed for determination of antibiotic susceptibility patterns. Phylogenetic grouping and the presence of integron-associated genes (int) were detected by the PCR technique. A high frequency of resistance was observed to cotrimoxazole (96.9%), ampicillin (85%), trimethoprim (80.1%) and cefazolin (79.6%); and 140 isolates (79.5%) were MDR. Carbapenems and fosfomycin were the most effective antibiotics. The majority of isolates (60.8%) belonged to the phylogenic group B2. Integrons were detected in 135 (76.7%) of isolates and, class I was the most common (63.6%) class. MDR isolates were found to be significantly associated with class І integrons. These isolates were found to be closely associated with the phylogenic group D (82%), however, the presence of class І integrons was higher among MDR isolates of the phylogroup B1. This pattern is believed to be due to other mechanisms such as the overexpression of the efflux pumps. Our findings show a significant correlation between MDR and the presence of class І integron. We conclude that class 1 integron plays an important role in the development of MDR UPEC, especially among the phylogroup B1