5 research outputs found
Advantages of employing multilevel monitoring wells for design of tunnels subjected to multi-aquifer alluvial
No full textFor tunnels being excavated through multiple aquifer formations, having precise knowledge of the aquifers' hydraulic head becomes essential for determining groundwater inflow into the tunnel and analyzing its stability, specifically using multilevel monitoring systems. In the multi-aquifer alluvial section of the Glas tunnel (Iran), since the hydraulic head calculations were based on the data obtained from single-piezometer boreholes, the excavation risk was assessed to be at high level and the tunnel seemed to be unstable, thus an incorrect conclusion was derived from the misleading data. To take cost mitigation measures into account, it was necessary to calculate the hydraulic head at tunnel level accurately. By installing nested and clustered wells the mean hydraulic head was measured to be 70 m, significantly different from the 90 m previously determined by boreholes. Considering the updated value, the groundwater inflow and bulkhead load,
formerly calculated as 0.65 m3/s and 9.5 bars, were determined to be 0.49 m3/s and 7.5 bars, respectively.For tunnels being excavated through multiple aquifer formations, having precise knowledge of the aquifers’ hydraulic head becomes essential for determining groundwater inflow into the tunnel and analyzing its stability, specifically using multilevel monitoring systems. In the multi-aquifer alluvial section of the Glas tunnel (Iran), since the hydraulic head calculations were based on the data obtained from single-piezometer boreholes, the excavation risk was assessed to be at high level and the tunnel seemed to be unstable, thus an incorrect conclusion was derived from the misleading data. To take cost mitigation measures into account, it was necessary to calculate the hydraulic head at tunnel level accurately. By installing nested and clustered wells the mean hydraulic head was measured to be 70 m, significantly different from the 90 m previously determined by boreholes. Considering the updated value, the groundwater inflow and bulkhead load, formerly calculated as 0.65 m3/s and 9.5 bars, were determined to be 0.49 m3/s and 7.5 bars, respectively
The independent contribution of desire thinking to problematic social media use.
No full textIn the present study, we investigated the role of desire thinking in problematic social media use (PSMU) whilst accounting for negative affect, impulsivity, and thought suppression. A sample of individuals with PSMU (n = 350) who used social media at least 8 h daily was recruited. Participants completed measures of negative affect, impulsivity, thought suppression, craving, desire thinking, and PSMU. Results indicated that negative affect, impulsivity, and thought suppression had significant indirect effects on craving and PSMU through the significant mediating role of desire thinking. The present study shows that desire thinking is an underlying mechanism linking established variables associated with PSMU (negative affect, impulsivity, and thought suppression) to craving and PSMU. Focusing efforts on the interruption of desire thinking may be beneficial to support individuals in disengaging from PSMU. [Abstract copyright: © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2022.
Novel chloroquine loaded curcumin based anionic linear globular dendrimer G2: A metabolomics study on Plasmodium falciparum in vitro using 1H NMR spectroscopy
No full textDue to side-effects and inefficiency of the drugs used in malaria treatment, finding alternative medicine with less side-effects has attracted much attention. In this regard, in the present study, nanocomposite synthesized and its effects on the metabolites of P. falciparum were investigated. Subsequent to synthesis of nanocomposites, characterization was carried out using nuclear magnetic resonance (NMR), liquid chromatography-mass spectrometry (LC-MS), scanning electron microscopy, dynamic light scattering and Fourier-transform infrared tests. Solubility and drug release were measured and its toxicity on Vero cell was assessed using the MTT assay. The antiparasitic effect of the nanocomposite on the metabolites of P. falciparum was investigated by 1H NMR spectroscopy. Among synthesized nanocomposites, the average size of 239 nm showed suitable solubility in water as well as slow drug release. The MTT assay showed no toxicity for Vero cell lines. Concentrations of 2.5 μg mL-1 of nanocomposite eliminated 82.6 of the total parasites. The most effected metabolic cycles were glyoxylate and dicarboxylate metabolism. In this study, 1H NMR spectroscopy was used with untargeted metabolomics to study the effect of the nanocomposite on P. falciparum. Playing an essential role in understanding drug-target interactions and characterization of mechanism of action or resistance exhibited by novel antiprotozoal drugs, can be achieved by targeting metabolic using LC-MS. Copyright © The Author(s), 2020. Published by Cambridge University Press
Tehran environmental and neurodevelopmental disorders (TEND) cohort study: Phase I, feasibility assessment
No full textPurpose: To advance knowledge about childhood neurodevelopmental disorders and study their environmental determinants, we conducted a study in Tehran, Iran to assess the feasibility of prospective birth cohort study. Methods: We evaluated participation of pregnant women, feasibility of sampling biological material, and health care services availability in Tehran in four steps: (1) first trimester of pregnancy; (2) third trimester of pregnancy; (3) at delivery; and (4) two to three months after delivery. We collected related data through questionnaires, also various biological samples were obtained from mothers (blood, urine, milk and nails�hands and feet) and newborns (umbilical cord blood, meconium, and urine samples) from February 2016 to October 2017. Results: overall 838 eligible pregnant women were approached. The participation rate was 206(25) in our study and about 185(90) of subjects were recruited in hospitals. Out of 206 participants in the first trimester, blood, urine, hand nail, and foot nail samples were collected from 206(100),193(93), 205(99), and 205(99), respectively. These values dropped to 65(54), 83(69), 84(70), and 84(70) for the remaining participants 120(58) in the third trimester, respectively. Also, we gathered milk samples from 125(60) of mothers at two to three months after delivery. Conclusion: Our findings suggest that hospitals were better places for recruitment of subjects in a birth cohort in Tehran. We further concluded that birth cohort study recruitment can be improved by choosing appropriate gestational ages. Obtaining the newborn�s urine, meconium, and umbilical cord blood were challenging procedures and require good collaboration between hospital staff and researchers. © 2020, Springer Nature Switzerland AG
Global, regional, and national burden of colorectal cancer and its risk factors, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019
No full textBackground Colorectal cancer is the third leading cause of cancer deaths worldwide. Given the recent increasing trends in colorectal cancer incidence globally, up-to-date information on the colorectal cancer burden could guide screening, early detection, and treatment strategies, and help effectively allocate resources. We examined the temporal patterns of the global, regional, and national burden of colorectal cancer and its risk factors in 204 countries and territories across the past three decades. Methods Estimates of incidence, mortality, and disability-adjusted life years (DALYs) for colorectal cancer were generated as a part of the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2019 by age, sex, and geographical location for the period 1990-2019. Mortality estimates were produced using the cause of death ensemble model. We also calculated DALYs attributable to risk factors that had evidence of causation with colorectal cancer. Findings Globally, between 1990 and 2019, colorectal cancer incident cases more than doubled, from 842 098 (95% uncertainty interval [UI] 810 408-868 574) to 2.17 million (2.00-2.34), and deaths increased from 518 126 (493 682-537 877) to 1.09 million (1.02-1.15). The global age-standardised incidence rate increased from 22.2 (95% UI 21.3-23.0) per 100 000 to 26.7 (24.6-28.9) per 100 000, whereas the age-standardised mortality rate decreased from 14.3 (13.5-14.9) per 100 000 to 13.7 (12.6-14.5) per 100 000 and the age-standardised DALY rate decreased from 308.5 (294.7-320.7) per 100 000 to 295.5 (275.2-313.0) per 100 000 from 1990 through 2019. Taiwan (province of China; 62.0 [48.9-80.0] per 100 000), Monaco (60.7 [48.5-73.6] per 100 000), and Andorra (56.6 [42.8-71.9] per 100 000) had the highest age-standardised incidence rates, while Greenland (31.4 [26.0-37.1] per 100 000), Brunei (30.3 [26.6-34.1] per 100 000), and Hungary (28.6 [23.6-34.0] per 100 000) had the highest age-standardised mortality rates. From 1990 through 2019, a substantial rise in incidence rates was observed in younger adults (age <50 years), particularly in high Socio-demographic Index (SDI) countries. Globally, a diet low in milk (15.6%), smoking (13.3%), a diet low in calcium (12.9%), and alcohol use (9.9%) were the main contributors to colorectal cancer DALYs in 2019. Interpretation The increase in incidence rates in people younger than 50 years requires vigilance from researchers, clinicians, and policy makers and a possible reconsideration of screening guidelines. The fast-rising burden in low SDI and middle SDI countries in Asia and Africa calls for colorectal cancer prevention approaches, greater awareness, and cost-effective screening and therapeutic options in these regions. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd.AuthorOverflow(404
