Causes & effects of upstream-downstream flow regime alteration over Catchment-Estuary-Coastal systems.

The construction of large dams along rivers has significantly changed the natural flow regime, reducing the inflow into many lakes and terminal wetlands. However, the question of the impact of dam operation on downstream estuarine wetlands has less been taken into account. Spatio-temporal flow regime alteration in the Mond River shows the complexity of drivers affecting the estuary-coastal system named the Mond-Protected Area in southern Iran. To this end, we applied river impact (RI) and Indicator of hydrological alteration (IHA) methods on monthly and daily river flow data across the basin. Based on the river impact method, a "drastic" impact below two in-operation (Tangab and Salman Farsi) dams, with RI values of 0.02 and 0.08, diminish to a 'severe' impact with RI value of 0.35 at the last gauge (Ghantareh) on the main corridor of the Mond river due to the addition of flow from a large mid-basin (about 20,254 km2). Furthermore, the degree of hydrological alteration (daily flow analysis) at mid-stream (e.g., Dehram gauges) was similar to the unregulated upstream tributaries (e.g., Hanifaghan gauges). The remote sensing analysis in the Mond Protected Area showed the prevailing impact of sea-level rise in the Persian Gulf with the inundation of the coastal area and a shift of vegetation in a landward direction which complied with standardized precipitation index (SPI) values as a meteorological drought indicator. Thus, the consequence of climate change (e.g., sea-level rise, draught) has a higher impact on the protected area than the upstream river regulation and land-use change in the Mond basin. The holistic approach and the catchment-level study allowed us to see the complexity of the drivers influencing the estuary-coastal system.

Laboratory Study of the Effect of Zeolite and Cement Compound on the Unconfined Compressive Strength of a Stabilized Base Layer of Road Pavement.

Soil stabilization using cement is regarded as one of the conventional methods to improve the engineering properties of soil used in infrastructure and road bodies. Considering the environmental problems caused by the production and consumption of cement, finding a suitable replacement for cement is necessary. The present study aims to experimentally evaluate the effect of using zeolite instead of cement in the stabilization of pavement layers. In this research, only 5% of cement was used in the control sample, while zeolite was used instead of cement in other samples by 20, 30, 40, and 60 wt.% of cement. According to the analysis, the highest unconfined compressive strength was obtained in the sample containing 30% (wt.% of cement) of zeolite instead of cement (equivalent to 1.5% of the total stabilizing materials) after 28 days of treatment, which was 29% more than that of the sample without zeolite. Evaluating the fracture strains reveals that using zeolite instead of cement increases the fracture strain by 33%, and in other words, changes the behavior of the sample from brittle mode to soft mode.

Effect of tinnitus distress on auditory steady-state response amplitudes in chronic tinnitus sufferers.

Tinnitus is a bothersome disorder of primarily unknown etiology that affects a large number of people worldwide. Tinnitus distress is the most common clinical complaint by tinnitus sufferers because it strongly affects their personal and social life. Many studies have been carried out to determine the relation between tinnitus pathophysiology and electrophysiological findings such as the auditory steady-state response (ASSR). The results of such studies have been contradictory. The current study aimed to detect a possible relation between tinnitus distress and ASSR amplitudes. The tinnitus participants were divided into high and low distress subgroups according to their tinnitus handicap inventory (THI) scores. The ASSR stimuli were carrier frequencies with low (500 Hz), mid (2000 Hz), and high (4000 Hz) amplitude-modulated tones. ASSR amplitudes were calculated in anterio-frontal (F3, Fz, F4), centro-frontal (FC3, FCz, FC4), left auditory (T3, C5, C3) and right auditory (C4, T4, C6) regions of interest (ROI). Twenty-four right-handed subjects with non-pulsatile chronic tinnitus and 23 normal matched participants participated in this study. For recording ASSR amplitudes were used from 32-electrode EEG recording. Two-way repeated-measurement ANOVA was used to compare the ASSR amplitudes. The findings showed that the ASSR amplitudes in the tinnitus group with low distress were higher (better) than in the group with high distress (p < 0.001). This finding was seen in anterio-frontal and right auditory regions and at all carrier frequencies. The results indicated that there is a relation between the ASSR amplitude and the degree of tinnitus distress as measured by the THI questionnaire.

Corrigendum to "Prediction of methane diffusion coefficient in water using molecular dynamics simulation" [Heliyon 6 (11) (November 2020) e05385].

[This corrects the article DOI: 10.1016/j.heliyon.2020.e05385.].

Prediction of methane diffusion coefficient in water using molecular dynamics simulation.

Diffusion coefficient is one the most effective factors in mass transfer calculation, which plays an important role in study at the molecular scale. In this study, Material Studio software was used to simulate the diffusion coefficient of methane in water through molecular dynamics. COMPASS force field was also used for optimization of atomic structures of methane and water, and Group-Based method was applied to model to calculate both van der Waals and electrostatic forces. In addition, Universal force field was used to optimize of amorphous cell, while Ewald and Atom-Based methods were applied for modeling and calculation of van der Waals and electrostatic potential energy at constant temperatures. The simulation duration for equilibrium of amorphous cell in both state of NVT and NVE was assumed 5ps. The impact of temperature as well as concentration on diffusion coefficient were investigated and results showed that the diffusion coefficient had linear relationship with temperature and third-degree polynomial relationship with concentration. As a result, of the simulation, the diffusion coefficient function versus temperature and concentration was developed.

The hypothetical relation between the degree of stress and auditory cortical evoked potentials in tinnitus sufferers.

Tinnitus, known as" the ringing in the ears," is a heterogeneous auditory disorder. Many studies have shown that tinnitus perception and its correlations are not limited to the activity of a single brain area, but there are several networks involved in tinnitus generation, perception, and interpretation. One of the most important complications and comorbidity of tinnitus is tinnitus distress. Various studies have revealed that tinnitus distress is the product of multiple networks activity, namely the tinnitus distress network; some of them overlap with the perception and cognitive networks. Such an overlapping between the tinnitus perception network and the distress network brings to mind the role of stress on tinnitus perception. Moreover, tinnitus perception networks overlap the auditory perception network leading to the hypothesis that tinnitus distress might affect the functional status of the auditory cortex indexed by the auditory evoked potentials (AEPs), and consequently, the diversity in findings of studies concerning the AEPs in tinnitus sufferers could be interpreted by the amount of stress they have.

Janus graphene oxide nanosheet: A promising additive for enhancement of polymeric membranes performance prepared via phase inversion.

Although polymeric membranes find important role in water and waste water treatment in recent years, their fouling is still an important problem. Application of hydrophilic nanoparticles (NPs) is one of the proposed methods for reducing fouling of membranes but their dispersion and stability in hydrophobic polymer matrix is challenging. In this study Janus functionalization of the NPs was introduced as a promising technique toward achieving this goal. Polysulfone (PSf) membranes containing various concentrations of graphene oxide (GO) nanosheets and Janus graphene oxide (Janus GO) nanosheets (as additives) were fabricated via phase inversion. The synthesized nanosheets were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy and dynamic light scattering (DLS). The prepared membranes also were then characterized by scanning electron microscopy (SEM), contact angle (CA), water uptake, porosity, mean pore size and casting solution viscosity. The membrane performance was also tested by determining pure water flux (PWF), bovine serum albumin (BSA) separation, flux reduction by fouling and flux recovery. CA reduced from 85° to 68° and PWF increased from 23.15 L/m2 h to 230.61 L/m2 h for PSF and Janus GO nanosheets containing membrane, respectively. Also investigation of antifouling performance of membranes revealed that membrane with the 1 wt.% of Janus GO nanosheets had higher water flux recovery ratio (FRR) and lower irreversible fouling (Rir) of 84% and 16%, respectively. These improvements were attributed to the better dispersion and stability of Janus GO nanosheets in the prepared mixed matrix membranes.

Antimicrobial resistance patterns and their encoding genes among Acinetobacter baumannii strains isolated from burned patients.

The purpose of this study was to determine the mechanisms and patterns of antimicrobial resistance among the isolates obtained from burned patients with wound infections at a teaching hospital in Tehran, Iran. A total of 23 Acinetobacter baumannii isolates were collected from patients with burn wound infections between August 2009 and July 2010 from a hospital in Tehran. The susceptibility of these strains against 11 antimicrobial agents was determined by E-test according to the CLSI guidelines. All the resistant strains were then subjected to PCR assay for 28 distinct resistance genes. The most active antimicrobial agent was colistin with 100% sensitivity followed by gentamicin, amikacin and imipenem with 69.5%, 52.1% and 51.1% sensitivity, respectively. The most frequent resistance genes detected were bla(OXA-51-like) genes (n=23; 100%) that was intrinsic to A. baumannii isolates, gyrA (n=23; 100%), carO (n=23; 100%), tetA (n=22; 95.5%), tetB (n=15; 65.2%), intI (n=13; 56.5%) and PER (n=12; 52.1%), respectively. In order to make a proper choice of antibiotic for burn patients, it would be beneficial to physicians to identify drug resistance patterns in A. baumannii isolates.

Rapid identification of Iranian Acinetobacter baumannii strains by single PCR assay using BLA oxa-51 -like carbapenemase and evaluation of the antimicrobial resistance profiles of the isolates.

The rapid identification of relevant bacterial pathogens is of utmost importance in clinical settings. The aim of this study was to test a rapid identification technique for A. baumannii strains from Tehran Hospitals and to determine the antibiotic resistance profiles of the isolates. A hundred strains of Acinetobacter spp. grown from clinical specimens were identified as A. baumannii by conventional methods. Using PCR a bla OXA-51 -like gene was detected in all A. baumannii isolates but not in other species of acinetobacter. More than half of the isolates proved resistant to a variety of antibiotics by the disk diffusion technique. The rate of resistance to gentamicin, imipenem, ampicillin-sulbactam and amikacin was determined to be 45%, 53%, 62% and 62%, respectively. Moreover, most isolates (more than 90%) showed resistance to cephalosporins. This study shows that the demonstration of the bla OXA-51-like gene is a reliable and rapid way for the presumptive identification of A. baumannii and reveals that the rate of antibiotic resistance is high in Iranian A. baumannii isolates to a variety of antibiotics.