13 research outputs found

    The driver responses to the vibration of tractor

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    Whole body vibration is one of the main causes of musculoskeletal disorders of drivers. The purpose of this study was to investigate the allowable exposer time, the care limit and driver response to the vibrations of the seat of ITM 475 Tractor. A three-way accelerometer was used to carry out the tests in the present study based on the ISO 2631-1 international vibration standard. The studied factors were engine rotational speed at three levels of 1000, 1500 and 2000 rpms, gear ratio (1, 2 and 3) and road at two level, dirt and asphalt. The obtained data were analyzed through factorial experiment based on completely randomized design with 18 treatments and three replications. The results showed that effects of the main factors and those of their interactions on the total vibration emitted from the tractor seat were significant at 1% probability level. The highest amount of whole body vibration on a dirt road was 1.49 m s-2 which took placed at 2000 rpm and the 3rd gear ratio. Consequently, the minimum exposure time and the driver care time limit were 1.16 and 0.14 h, respectively. This treatment was in very uncomfortable range. The maximum whole body vibration for 8 h ride on ITM 475 was 0.85 m s-2. Therefore, it is necessary to reduce whole body vibration of the studied tractor via designing a cabin and/or a new seat

    Non-surgical management of spinal epidural hematoma after kyphoplasty: A case report

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    Kyphoplasty and Vertebroplasty (VP) are accepted therapeutic approaches to treat pain associated with vertebral compression fractures. Major complications such as cord or root compression, subdural and epidural hematomas (EDH), as well as pulmonary emboli, have been reported in less than 1% of patients. Spinal EDH is an extremely rare complication that usually happens a few hours after the procedure. We report a case of spinal EDH that developed four days after a successful kyphoplasty

    Impact of COVID-19 Event on the Air Quality in Iran

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    The first novel coronavirus case was confirmed in Iran in mid-February 2020. This followed by the enforcement of lockdown to tackle this contagious disease. This study aims to examine the potential effects of the COVID-19 lockdown on air quality in Iran. From 21st March to 21st April in 2019 and 2020, The Data were gathered from 12 air quality stations to analyse six criteria pollutants, namely O3, NO2, SO2, CO, PM10, and PM2.5. Due to the lack of ground-level measurements, using satellite data equipped us to assess changes in air quality during the study on Iranian megacities, especially in Tehran, i.e., the capital of Iran. In this city, concentrations of primary pollutants (SO2 5–28%, NO2 1–33%, CO 5–41%, PM10 1.4–30%) decreased with spatial variations. Although, still SO2, NO2, and PM10 exceeded the WHO daily limit levels for 31 days, 31 days, and four days, respectively. Conversely, O3 and PM2.5 increased by 0.5–103% and 2–50%. In terms of the national air quality, SO2 and NO2 levels decreased while AOD increased during the lockdown. Unfavourable meteorological conditions hindered pollutant dispersion. Moreover, reductions in the height of planetary boundary layer and rainfall were observed during the lockdown period. Despite the adverse weather conditions, a decrease in primary pollutant levels, confirms the possible improvements on the air quality in Iran

    Impact of roof rain water harvesting of runoff capture and household consumption

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    In recent years, the occurrence of floods is one of the most important challenges facing in Hamadan city. In the absence/inefficiency of urban drainage systems, rainwater harvesting (RWH) systems as low-impact development (LID) methods can be considered as a measure to reduce the floods. In this study, three scenarios concerning the RWH from the roof surfaces are studied to evaluate the type of the harvested water on reducing flooding. In the first scenario, which indicates the current situation in the studied area, it is indicated that there is no harvest of the roof surfaces in the studied area. The second scenario is about the use of water harvested from the roof surfaces for household purposes. The third scenario also refers to the use of harvested water for irrigation of gardens. The simulation results of these three scenarios using the Soil Conservation Service (SCS) method in the Hydrologic Modeling System (HEC-HMS) model reveal that if the second scenario is implemented, the runoff volume decreases from 28 to 12% for the return period from 2 to 100 years. However, in the third scenario, this reduction in runoff volume will be 48 and 27% for return periods of 2 to 100 years, respectively. Therefore, the results of this study indicate that the use of harvested water can also affect the reduction on runoff volume

    ASSESSMENT OF THE ASSOCIATION BETWEEN DUST STORMS AND COVID-19 INFECTION RATE IN SOUTHWEST IRAN

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    This study assesses a plausible correlation between a dust intrusion episode and a daily increase in COVID-19 cases. A surge in COVID-19 cases was observed a few days after a Middle East Dust (MED) event that peaked on 25th April 2020 in south west Iran. To investigate potential causal factors for the spike in number of cases, cross-correlations between daily combined aerosol optical depths (AODs) and confrmed cases were computed for Khuzestan, Iran. Additionally, atmospheric stability data time series were assessed by covering before, during, and after dust intrusion, producing four statistically clustered distinct city groups. Groups 1 and 2 had diferent peak lag times of 10 and 4-5 days, respectively. Since there were statisti cally signifcant associations between AOD levels and confrmed cases in both groups, dust incursion may have increased population susceptibility to COVID-19 disease. Group 3 was utilized as a control group with neither a signifcant level of dust incursion during the episodic period nor any signifcant associations. Group 4 cities, which experienced high dust incur sion levels, showed no signifcant correlation with confrmed case count increases. Random Forest Analysis assessed the infuence of wind speed and AOD, showing relative importance of 0.31 and 0.23 on the daily increase percent of confrmed cases, respectively. This study may serve as a reference for better understanding and predicting factors afecting COVID-19 transmission and difusion routes, focusing on the role of MED intrusions

    Delayed Effect of Dendritic Cells Vaccination on Survival in Glioblastoma: A Systematic Review and Meta-Analysis

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    Background: Dendritic cell vaccination (DCV) strategies, thanks to a complex immune response, may flare tumor regression and improve patients’ long-term survival. This meta-analysis aims to assess the efficacy of DCV for newly diagnosed glioblastoma patients in clinical trials. Methods: The study databases, including PubMed, Web of Knowledge, Google Scholar, Scopus, and Cochrane, were searched by two blinded investigators considering eligible studies based on the following keywords: “glioblastoma multiforme”, “dendritic cell”, “vaccination”, “immunotherapy”, “immune system”, “immune response”, “chemotherapy”, “recurrence”, and “temozolomide”. Among the 157 screened, only 15 articles were eligible for the final analysis. Results: Regimens including DCV showed no effect on 6-month progression-free survival (PFS, HR = 1.385, 95% CI: 0.822–2.335, p = 0.673) or on 6-month overall survival (OS, HR = 1.408, 95% CI: 0.882–2.248, p = 0.754). In contrast, DCV led to significantly longer 1-year OS (HR = 1.936, 95% CI: 1.396–2.85, p = 0.001) and longer 2-year OS (HR = 3.670, 95% CI: 2.291–5.879, p = 0.001) versus control groups. Hence, introducing DCV could lead to increased 1 and 2-year survival of patients by 1.9 and 3.6 times, respectively. Conclusion: Antitumor regimens including DCV can effectively improve mid-term survival in patients suffering glioblastoma multiforme (GBM), but its impact emerges only after one year from vaccination. These data indicate the need for more time to achieve an anti-GBM immune response and suggest additional therapeutics, such as checkpoint inhibitors, to empower an earlier DCV action in patients affected by a very poor prognosis

    Health risk assessment of the European inhabitants exposed to contaminated ambient particulate matter by potentially toxic elements

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    PM10-associated potential toxic elements (PTEs) can enter the respiratory system and cause health problems. In the current study, the health risk indices caused by PM10 inhalation by adults, children, and infants in 158 European cities between 2013 and 2019 were studied to determine if Europeans were adversely affected by carcinogenic and non-carcinogenic factors or not. The Mann–Kendall trend test examined PM10's increasing or decreasing trend. Random Forest analysis was also used to analyse meteorological factors affecting PM10 in Europe. Hazard quotient and cancer risk were estimated using PM10-associated PTEs. Our results showed a decline in continental PM10 concentrations. The correlation between PM10 concentrations and temperature (−0.40), PBLH (−0.39), and precipitation were statistically strong (−0.21). The estimated Pearson correlation coefficients showed a statistically strong positive correlation between As &amp; Pb, As &amp; Cd, and Cd &amp; Pb during 2013–2019, indicating a similar origin. PTEs with hazard quotients below one, regardless of subpopulation type, posed no noncancerous risk to Europeans. The hazard quotient values positively correlated with time, possibly due to elevated PTE levels. In our study on carcinogen pollution in Europe between 2013 and 2019, we found unacceptable levels of As, Cd, Ni, and Pb among adults, children, and infants. Carcinogenic risk rates were highest for children, followed by infants, adult women, and adult men. Therefore, besides monitoring and mitigating PM concentrations, effective control of PM sources is also needed.</p

    Empty sella in somatotropic pituitary adenomas; a series of 23 cases

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    PurposeWe aimed to investigate empty sella syndrome in somatotrophic pituitary adenoma for possible etiology, complications, and treatment options.MethodAmong over 2,000 skull base masses that have been managed in our center since 2013, we searched for growth hormone-producing adenomas. Clinical, surgical, and imaging data were retrospectively collected from hospital records to check for sella that lacked pituitary tissue on routine imaging.ResultIn 220 somatotrophic adenomas, 23 patients had an empty sella with surgical and follow-up data. The mean age of the sample was 46 years with the same male-to-female ratio. Five cases had partial empty sella and the rest were complete empty sellas. The most common simultaneous hormonal disturbance was high prolactin levels. Six had adenoma invasion into the clivus or sphenoid sinus and 10 had cavernous sinus intrusion. Peri-operative low-flow and high-flow cerebrospinal fluid (CSF) leaks were encountered in one and two patients, respectively, which were successfully sealed by abdominal fat. The majority of cases required growth hormone replacement therapy while it was controlled without any replacement therapy in nine patients. No pituitary hormonal disturbance occurred after transsphenoidal surgery except for hypothyroidism in one patient.ConclusionAn empty sella filled with fluid can be detected frequently in pituitary adenomas, especially in the setting of acromegaly. The pituitary gland may be pushed to the roof of the sella and might be visible as a narrow rim on imaging or may be detected in unusual places out of the sella. The pathophysiology behind such finding originates from soft and hard tissue changes and CSF pressure alternations during abundant growth hormone production
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