جستجوی مقالات مرتبط با کلیدواژه « time factors » در نشریات گروه « پزشکی »

Exposure to air pollution is a major health problem worldwide. This study aimed to investigate the effect of the level of air pollutants and meteorological parameters with their related lag time on the transmission and severity of coronavirus disease 19 (COVID-19) using machine learning (ML) techniques in Shiraz, Iran.

Study Design:

 An ecological study.

In this ecological research, three main ML techniques, including decision trees, random forest, and extreme gradient boosting (XGBoost), have been applied to correlate meteorological parameters and air pollutants with infection transmission, hospitalization, and death due to COVID-19 from 1 October 2020 to 1 March 2022. These parameters and pollutants included particulate matter (PM2), sulfur dioxide (SO2 ), nitrogen dioxide (NO2 ), nitric oxide (NO), ozone (O3 ), carbon monoxide (CO), temperature (T), relative humidity (RH), dew point (DP), air pressure (AP), and wind speed (WS).

Based on the three ML techniques, NO2 (lag 5 day), CO (lag 4), and T (lag 25) were the most important environmental features affecting the spread of COVID-19 infection. In addition, the most important features contributing to hospitalization due to COVID-19 included RH (lag 28), T (lag 11), and O3 (lag 10). After adjusting for the number of infections, the most important features affecting the number of deaths caused by COVID-19 were NO2 (lag 20), O3 (lag 22), and NO (lag 23).

Our findings suggested that epidemics caused by COVID-19 and (possibly) similarly viral transmitted infections, including flu, air pollutants, and meteorological parameters, can be used to predict their burden on the community and health system. In addition, meteorological and air quality data should be included in preventive measures.

Sepsis is a life-threatening and common cause of Emergency department (ED) referrals. Out-of-hourstaffing is limited in ED, which may potentially affect fluid administration. This study aimed to investigate fluid volumevariation in out-of-hour vs. routine-hour admissions.

The present study is a post-hoc analysis of a multicen-tre, prospective, observational study investigating fluid administration in ED patients with suspected infection, fromJan 20th - March 2nd, 2020. Patient groups were “routine-hours” (RH): weekdays 07:00-18:59 or “out-of-hours” (OOH):weekdays 19:00-06:59 or Friday 19:00-Monday 06:59. Primary outcome was 24-hour total fluid volumes (oral + intra-venous (IV )). Secondary outcomes were total fluids 0-6 hours, oral fluids 0-6 and 0-24 hours, and IV fluids 0-6 and 0-24hours. Linear regression adjusted for site and illness severity was used.

734 patients had suspected infection;449 were admitted during RH and 287 during OOH. Mean (95% CI) total 24-hour fluid volumes were equal in simple in-fection and sepsis regardless of admission time: Simple infection RH: 3640 (3410 - 3871) ml and OOH: 3681 (3451 - 3913)ml. Sepsis RH: 3671 (3443;3898) ml and OOH: 3896 (3542;4250) ml. Oral fluids 0-6h were reduced in simple infectionand sepsis among OOH vs. RH. Sepsis patients received more 0-6-hour IV fluid when admitted OOH vs. RH. There wereno associations between admission time and 0-24-hour oral or IV volumes in simple infection or sepsis.

Admission time did not have an association with 24-hour total fluid volumes. Sepsis patients admitted during OOHreceived more 0-6-hour IV fluids than RH patients, and simple infection and sepsis patients received less oral fluid in0-6 hours if admitted during OOH vs. RH.

Extracellular signal-regulated kinase 1 and 2 (ERK1/2) are important members of mitogen-activated protein kinases (MAPK), which are actively involved in the shaping of cellular responses to different stimuli; however, these responses are somehow contradicting. It is believed that time is a crucial factor in the determination of these effects. Therefore, the present work was designed to obtain a more vivid view about the effect of time on ERK activity and its relation to cell viability.

In the first step, we challenged cultured PC12 cells with different doses of lipopolysaccharides (LPS) for different time intervals (3, 6, 24 and 48h) and the cell viability was checked by MTT test. Thereafter, we cultured the cells in 6-well plates and treated them with the effective dose (10μg/ml) for the abovementioned intervals and the level of ERK phosphorylation, as the active form, was assessed in the Western blotting analysis.

The results showed that treating cells with 10μg/ml LPS reduces cell viability after 48h. While being ineffective in shorter periods of time, ERK activity has a fluctuating trend, so that it reaches the highest level at 6h, thereafter it declines to the lowest level at 24h and partially increases again at 48h.

These results imply that time is a determinant factor in the activity of ERK and single-point assessments may result in misinterpretation.

Shade guide discoloration after disinfection can interfere with the appropriate color selection for dental restorations. Since one of the most important issues for patients is the color of the final restoration, the discoloration of shade guides due to disinfectants will be important. Infection control is a definite and important matter in dentistry. Due to the contradictory results of studies on the effect of disinfectants on shade guide discoloration, this study aimed to examine the discoloration of the Vita classical shade guide by glutaraldehyde disinfectant. 

In this experimental study, samples of A4, B4, C4, and D4 colors were selected from the Vitapan classical shade guide, 10 pieces each (40 samples in total). Three samples of each color were immersed in distilled water as a control while the other seven were immersed in a 2% glutaraldehyde disinfectant solution. The shade pilot spectrophotometer was used for colorimetry, which was performed at baseline and 24, 48, and 72 hours after the immersion. The color of the samples was evaluated based on the CIE Lab system. The data were analyzed with two-way analysis of variance (ANOVA) and Tukeychr('39')s test.

The rate of color change (ΔE) of the samples was higher in the glutaraldehyde group than in distilled water (P<0.05). In addition, color change in both groups showed a significant difference at different times (P<0.05).

The Vitapan classical color samples discolor by immersion in 2% glutaraldehyde disinfectant after 24, 48, and 72 hours, but this color change is not clinically detectable (ΔE<1).