•Post-Traumatic stress disorder is common in coronavirus outbreaks.•Mental care is important during the present COVID-19 pandemic.•This study showed about 3 in every 10 survivors of Coronavirus had ...PTSD symptoms.•This study showed about 2 in every 10 healthcare workers had PTSD symptoms.
: Infectious disease outbreaks affect physical and mental health of humans worldwide. Studies showed that the prevalence of post-traumatic stress disorder (PTSD) symptoms increased in these conditions. This systematic-review and meta-analysis aimed to assess the prevalence of PTSD related symptoms in coronavirus outbreaks.
: Systematic search of literature was conducted in Scopus, Embase, PubMed, and Web of Science. Google Scholar and Grey literature including conference proceedings were also checked. Published articles from November 1, 2012 until May 18, 2020 were searched. Subgroup analysis, meta-regression and sensitivity analysis were also conducted to assess heterogeneity.
: We found 38 articles with 19,428 individuals met the eligibility criteria. Of these papers, 35 studies were included in meta-analysis. The prevalence of PTSD symptoms was estimated to be about 18% (95%CI: 15% to 20%). These symptoms were more frequent in cohort studies (29%) compared to cross-sectional (15%) and case-control (11%) studies. Prevalence rates of PTSD symptoms in MERS (36%) outbreaks were higher than SARS (18%) and COVID-19 (9%) outbreaks. Meta-regression showed that the geographical location of study was the source of heterogeneity (R2: 19.8%, P-value: 0.003). Meta-analysis reported that about three in every ten survivors of coronavirus infection, about two in every ten healthcare workers, and about one in every ten individuals of general population experienced PTSD symptoms in outbreaks.
: PTSD cannot be objectively assessed and this can lead to information bias of included studies.
: PTSD symptoms are shown to be common in coronavirus outbreaks. Mental care should be, therefore, considered in the present COVID-19 pandemic.
A conventional triaxial test device was modified to characterize the hydro-mechanical behavior of a loessial soil during isotropic and shear loadings. This device is capable of precise and continuous ...measurements of water outflow during the application of loading. The tests were performed on “undisturbed” cylindrical specimens, which were taken from loessial deposits in Gorgan, a city in the northeast of Iran. Experimental measurements indicate that the hydro-mechanical behavior of loess is highly affected by the extent of applied mean net stress and the level of suction. During both isotropic and shearing stages of loading, the tested specimens may exhibit collapse, abrupt decrease in volume or sudden positive volumetric strain, upon wetting or applied loading. However, the magnitude and extent of collapse are different depending on the applied state of the stress and the hydro-mechanical loading path. The results of the experiments reveal that the peak shear strength of the soil increases, as the applied mean net stress during isotropic loading or the applied matric suction increases. The shearing test results are also used to investigate the efficiency of suction stress in describing the state of stress for unsaturated loessial soils. The outcome indicated a unique critical state line for unsaturated specimens under different stress paths and loading conditions. Furthermore, considering the effective stress concept, a hardening constitutive law is presented in this study to demonstrate the hardening/softening behavior of the collapsible loessial soils.
•Hydro-mechanical behavior of an undisturbed collapsible loessial soil is studied.•A conventional Triaxial test device was modified and used for unsaturated testing.•Isotropic consolidation, wetting and shear loadings are applied to the tested soil.•The effective stress approach and the suction stress concept are considered.•A hardening model is presented to predict the yielding behavior of the tested soil.
AbstractThe ultimate bearing capacity of shallow foundations on unsaturated soils is investigated through the concept of suction-dependent effective stress. The first approach is a new analytical ...solution considering the influence of matric suction on ultimate bearing capacity by extending Vesic’s solution for saturated soils. Accordingly, a modification factor has been introduced as a nonlinear function of matric suction for tuning the cohesion-dependent component in the bearing capacity equation. The second approach is incorporating the unsaturated effective stress state in conjunction with the suction-dependent cohesion into a three-dimensional (3D) finite-difference code. In developing the 3D simulations, the variation in matric suction versus the depth of the soil was considered as well as the dependency of the degree of saturation on the soil suction. In addition, in three-dimensional numerical analyses, the input material parameters were modified to take into account the suction-stress concept in unsaturated soils. To assess the validity of the analytical and numerical approaches, four series of experimental data from physical plate load tests conducted under different matric suctions and embedment depths of the footing were selected. Accordingly, water retention curves of different test materials were considered as key input parameters used in both approaches to improve model predictions. Results from the analytical approach show the dependency of the presented correction factor on the soil properties, geometrical aspects of the foundation, and its embedding depth. In addition, the 3D numerical simulation revealed the suitable functionality of the effective stress approach on predicting the load-displacement behavior of shallow foundations on unsaturated soils. Moreover, the comparison between analytical, numerical, and experimental data shows a good conformance between the experimental test results, analytical solutions, and numerical predictions, especially for sandy soils.
In this paper, thermomechanical (TM) behavior of laterally loaded energy piles is investigated through analytical and numerical studies. Accordingly, the ultimate lateral load capacity, and the ...internal moment and horizontal displacement of the pile under service lateral loads, were assessed. Initially, a thermo-elastic-based analytical solution was proposed, and afterwards, a 3D numerical finite element (FE) model was constructed to investigate the effect of different soil parameters, temperature variation and mechanical load conditions on the behavior of energy piles in different soils. Then, the analytical and numerical results were validated against experimental data, and vast analytical/numerical studies were carried out on the TM parameters affecting the behavior of laterally loaded energy piles. Finally, considering the analytical and numerical results, adjusting relationships were introduced to estimate the lateral bearing capacity and the maximum lateral displacement parameters, more precisely. The results showed that in clayey and sandy soils, the ultimate lateral bearing capacity increases by increasing the temperature or by decreasing the external moment. Moreover, heating was found to have an increasing effect on the internal moments and the maximum lateral displacements of the piles embedded in clayey soils, but it had a decreasing effect on the piles embedded in sandy soils.
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Anxiety disorders are the most prevalent psychiatric disorders and a leading cause of disability. While there continues to be expansive research in posttraumatic stress disorder (PTSD), depression ...and schizophrenia, there is a relative dearth of novel medications under investigation for anxiety disorders. This review's first aim is to summarize current pharmacological treatments (both approved and off-label) for panic disorder (PD), generalized anxiety disorder (GAD), social anxiety disorder (SAD), and specific phobias (SP), including selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), azapirones (e.g., buspirone), mixed antidepressants (e.g., mirtazapine), antipsychotics, antihistamines (e.g., hydroxyzine), alpha- and beta-adrenergic medications (e.g., propranolol, clonidine), and GABAergic medications (benzodiazepines, pregabalin, and gabapentin). Posttraumatic stress disorder and obsessive-compulsive disorder are excluded from this review. Second, we will review novel pharmacotherapeutic agents under investigation for the treatment of anxiety disorders in adults. The pathways and neurotransmitters reviewed include serotonergic agents, glutamate modulators, GABAergic medications, neuropeptides, neurosteroids, alpha- and beta-adrenergic agents, cannabinoids, and natural remedies. The outcome of the review reveals a lack of randomized double-blind placebo- controlled trials for anxiety disorders and few studies comparing novel treatments to existing anxiolytic agents. Although there are some recent randomized controlled trials for novel agents including neuropeptides, glutamatergic agents (such as ketamine and d-cycloserine), and cannabinoids (including cannabidiol) primarily in GAD or SAD, these trials have largely been negative, with only some promise for kava and PH94B (an inhaled neurosteroid). Overall, the progression of current and future psychopharmacology research in anxiety disorders suggests that there needs to be further expansion in research of these novel pathways and larger-scale studies of promising agents with positive results from smaller trials.
This paper examines the ultimate bearing capacity of energy piles in sandy and clayey soils by conducting numerical modeling under different thermal loads, fluid-pipe configurations and fluid ...characteristics. Accordingly, U and W-shaped fluid-pipes with different diameters were simulated using ANSYS-FLUENT software, under different inlet flow rates, fluid temperatures and ground temperatures. Moreover, a semi-empirical analytical solution is proposed for predicting the outlet temperature for different pipe configurations. Then, the energy piles were modeled using ABAQUS FE-software, and the effect of temperature distribution in U, double-U and W-shaped pipes on the ultimate bearing capacity was studied, in heating/cooling conditions. Both numerical simulations and the analytical solution were validated against experimental data. Results showed that under constant flow rate, initial inlet temperature and pipe diameter, the differences between the inlet and outlet temperature of the heat exchange fluid in the U-shaped pipes was less than that obtained for the W-shaped pipes. Also, for constant inlet temperature and pipe diameter, the temperature difference decreased when the inlet flow rate increased. It was found that under constant thermal loading conditions, the changes in the ultimate bearing capacity were higher in piles with double U-shaped pipes, followed by U-shaped pipes, and lowest for W-shaped pipes.
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•The ultimate bearing capacity of energy piles in different soils is investigated.•Different fluid characteristics and various pipe configurations are examined.•CFD and TM simulations are conducted and validated versus experimental data.•An empirical-analytical solution is proposed for predicting the outlet temperature.•Functional graphs are presented for calculations of the ultimate bearing capacity.
Abstract
The desulphurization of hydrocarbon fuels with high sulphur content and a wide variety of sulphur‐containing compounds brings significant challenges. In the present work, the non‐catalytic ...desulphurization of vacuum gas oil (VGO) and natural gas condensate mixed fuel has been investigated. In this regard, ozone was employed as the oxidant in a bubble column gas–liquid contactor, and an extraction step was further incorporated. The effects of the oxidation reactor scheme, ozonation time, and extraction with different solvents, applying pre‐ and post‐extraction strategies (i.e., ozonation/extraction/extraction and extraction/ozonation/extraction), have been studied. It was found that pre‐extraction of mixed fuel increases the oxidative desulphurization (ODS) efficiency due to the removal of light sulphur‐containing compounds (SCCs). N‐methyl‐2‐pyrrolidone (NMP) has been found to be the most effective extraction agent, removing 44% of sulphur by pure extraction and 77.4% by ozonation + extraction. However, in terms of fuel loss, dimethylformamide (DMF) performs better than NMP, and it has been shown to be the most appropriate solvent for achieving a 90% desulphurization ratio. Finally, it was found that the applied procedure could effectively remove the wide range of SCCs, especially refractive components such as benzothiophene (BT) and dibenzothiophene (DBT).
In this study, an analytical model is developed to establish a framework for predicting the coefficient of lateral soil pressure in unsaturated soils. To this end, the disturbed state concept (DSC) ...is implemented along with the concept of effective stress for unsaturated soils. Accordingly, upper and lower limits are considered for the structural disturbance of the soil during hydromechanical loading, and a suction-dependent analytical framework is proposed for calculating continuous variations of the coefficient of lateral soil pressure, from the at-rest to active state of the soil, against the effective vertical stress parameter. The functionality of the proposed model is verified against experimental results obtained from a series of laboratory unsaturated drained tests conducted on two different soil materials (a Sand–Kaolin mixture and Firouzkouh Clay) with two initial void ratios. Quantitative comparisons show excellent conformance between the predicted and experimental data. A practical example of calculating lateral soil pressure on a gravity retaining wall is also presented, in which the results obtained from the model presented in this study and the conventional classic approach of calculating the lateral soil pressure on retaining walls are compared. It is hoped that the results of this study can help researchers and designers to obtain improved values of lateral soil pressure in unsaturated soil.
Background/Objectives
Nitrous oxide (N2O) is known to have abuse potential, although debate regarding the toxic effects of such abuse continues. Our objective was to review the case literature and ...present the neurologic, psychiatric and medical consequences of N2O abuse.
Methods
A systematic literature review was completed for case reports using keywords “nitrous oxide” with “abuse/abusing” or “misuse/misusing” or “overuse/overusing” or “addiction.” Non‐English‐language cases and cases not involving direct toxic effects of N2O were excluded as were commentaries or personal essays. Clinical presentation, frequency of N2O abuse, laboratory studies, imaging, ancillary tests, treatments and outcomes were collected from case reports.
Results
Our review returned 335 Pubmed, 204 Web of Science, 73 PsycINFO, 6 CINAHL, 55 EMBASE and 0 Grey Literature results, and after exclusion and removal of duplicates, 91 individual cases across 77 publications were included. There were also 11 publications reporting 29 cases of death related to N2O abuse. The majority of cases (N = 72) reported neurologic sequelae including myeloneuropathy and subacute combined degeneration, commonly (N = 39) with neuroimaging changes. Psychiatric (N = 11) effects included psychosis while other medical effects (N = 8) included pneumomediastinum and frostbite. Across all cases N2O abuse was correlated with low or low‐normal Vitamin B12 (cyanocobalamin) levels (N = 52) and occasionally elevated homocysteine and methylmalonic acid.
Conclusions/Scientific Significance
N2O abuse represents a significant problem because of the difficulty involved with identification and the toxicity related to chronic abuse including possible death. Health professionals should be aware of the toxic effects of N2O and be able to identify potential N2O abuse. (Am J Addict 2016;25:358–369)
Abstract
In this paper, the axial ultimate bearing capacity of fixed-head concrete energy piles is studied considering various soils and thermomechanical loads, through numerical and analytical ...models. Accordingly, an axisymmetric numerical approach was adopted using the finite-element method by considering temperature-dependent soil and pile–soil interface parameters, and the results were validated using experimental datasets. Quantitative and statistical comparisons showed an acceptable agreement between the numerical predictions and experimental observations. Then, a vast numerical parametric study was carried out on various soil strength parameters and different thermomechanical conditions to evaluate the changes in compressive/tensile ultimate bearing capacity of the fixed-head energy piles in dry and saturated soils. The results showed that temperature changes and environmental conditions have significant effects on the ultimate load capacity of energy piles. Thereafter, different analytical approaches were developed for various soil types and thermomechanical loading conditions to assess the soil–structure and thermomechanical interactions between the examined energy piles and the surrounding soil. Accordingly, by comparing the obtained results from the analytical and numerical solutions, the best analytical approach for each soil type and load condition was proposed. Finally, by performing an analytical sensitivity study on the geometrical aspects of the examined energy piles, the remarkable effects of the pile diameter and pile length on the ultimate load capacity of energy piles were revealed.
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