A Retrospective Study of Serum Calcium Status in Tehran, Iran (105,128 Samples, from 2009-2018).

Background: Calcium is a necessary mineral for life to keep the body and bones healthy. Various factors including hormones, diet, age, and gender affect serum calcium status. The aim of this sturdy was to assess the serum calcium level (SCL) of Tehran population, which has about 10 million multi-Ethnic populations and represents from the whole country. Methods: In this retrospective study, the measured SCL of 105,128 individuals referred to different laboratories of Tehran, Iran were evaluated and its relationship with the age, gender, seasons, and different years during 2009-2018, were analyzed. Results: After excluding outliers, 91,257samples remained, which 61162 (58.64%) and 30,095 (41.36%) were female and male, respectively. The mean SCL was 9.36 (9.35, 9.37) mg/dl (95%CI). The highest and lowest SCLs were 3.1 and 18.2mg/dl, respectively. From the total study population, 74127 (81.23%) had normal SCLs, 14110 (15.46%) had hypocalcemia, and 3020 (3.31%) had hypercalcemia. SCLs were normal in 83.6% of men and 79.66% of women. Women had a significantly higher frequency of hypocalcemia compared to men (17.2% vs. 12.83%, p<0.0001). Conclusion: Normal and abnormal SCLs were significantly different in age groups and in both genders. It means that gender and age affect SCLs. Every year of increasing age, reduces the chance of hypercalcemia by 40%, significantly. Age seems to affect hypercalcemia more than hypocalcemia. Age in men increases the risk of hypocalcemia, and reduces the risk of hypocalcemia in women. Therefore, it is recommended to encourage dietary calcium intake among premenopausal women and older men.

A method using porous media to deliver gas-phase phthalates rapidly and at a constant concentration: Effects of temperature and media.

Phthalates are widely used as additives to consumer products. Many diseases have been shown to be related to the uptake of phthalates. To achieve equilibrium constant phthalate generation for mass transfer and exposure experiments, the present study developed a porous media based method using Teflon generators connected to the media with stainless steel connectors. Carbon sponges with the porosities of 20 ppi (pores per inch), 30 ppi, 40 ppi and honeycomb ceramics of 14 ppi were used as porous media fillers to evaluate the effect of temperature-controlled states, materials, and pore sizes on the generating performance of phthalates. The results showed that 30 ppi carbon sponge fillers at 25.0 ±â€¯0.4 °C performed satisfactorily. DMP, DiBP and DEHP were used as examined phthalates and were generated at 12,800 ±â€¯740 µg/m3, 330 ±â€¯13 µg/m3 and 2.37 ±â€¯0.15 µg/m3, respectively. The times to reach stable concentrations were 4.5 h, 18.5 h and 89.5 h, respectively. The reproducibility of DiBP and DEHP delivery deviated by less than 2.4%. Long-term generating experiments should be performed in the future. The porous media based method could stably deliver gaseous PAEs and tends to be widely used in the research of the adsorption of PAEs on surfaces (airborne particles, settled dust and indoor surfaces) and exposure experiments.

Effect of Aluminum Substrate Surface Modification on Wettability and Freezing Delay of Water Droplet at Subzero Temperatures.

In this study, we have investigated the freezing delay of a water droplet on precooled substrates of an aluminum alloy that is commonly used for heat-exchanger fins. The surfaces of the substrates were modified to obtain surfaces with different hydrophilicity/hydrophobicity and different surface chemistry but without significantly modifying the surface topography. The freezing delays and water contact angles were measured as a function of the substrate temperature and the results were compared to the predictions of the heterogeneous ice nucleation theory. Although the trends for each sample followed the trend in this theory, the differences in the extents of freezing delays were in apparent disagreement with the predictions. Concretely, a slightly hydrophilic substrate modified by (3-aminopropyl) triethoxysilane (APTES) showed longer freezing delays than both more hydrophilic and more hydrophobic substrates. We suggest that this is because this particular surface chemistry prevents ice formation at the interface of the substrate, prior to the deposition of the water droplet. On the basis of our results, we suggest that not only wettability and topography but also the concrete surface chemistry plays a significant role in the kinetics of the ice formation process when a water droplet is placed on a precooled substrate.

The association between air pollution and weather conditions with increase in the number of admissions of asthmatic patients in emergency wards: a case study in Kermanshah.

BACKGROUND: Industrialization and urbanization had a devastating impact on public health and caused an increase in health related morbidity and mortality. In fact, asthma is a chronic condition which is considered as one of the significant challenges of public health. In this study, we investigated the association of air pollution and weather conditions with excess emergency ward admissions of asthmatic patients in Kermanshah hospitals. METHODS: This was an ecological study. The total number of hospital admissions to emergency wards from all related and major hospitals of Kermanshah was collected from September 2008 through August 2009. In addition, data on air pollution as well as meteorological data were collected from the Environmental Protection Agency and Meteorological Organization of Kermanshah. To determine the association between the number of hospitalization due to asthma with those parameters, Poisson regression was used. RESULTS: The results of Poisson regression revealed a significant association between carbon monoxide, ozone, nitrogen dioxide and temperature with emergency room visits due to asthma in Kermanshah. No associations were found for sulfur dioxide or for particulate matter. CONCLUSION: This study provides further evidence for the significant effect of monoxide carbon on asthma; and it suggests that temperature may have a role in the exacerbation of asthma. However, due to the multi-factorial nature of asthma, other factors also play a major role in the development and exacerbation of this illness.

Indoor particles affect vascular function in the aged: an air filtration-based intervention study.

RATIONALE: Exposure to particulate matter is associated with risk of cardiovascular events, possibly through endothelial dysfunction, and indoor air may be most important. OBJECTIVES: We investigated effects of controlled exposure to indoor air particles on microvascular function (MVF) as the primary endpoint and biomarkers of inflammation and oxidative stress as secondary endpoints in a healthy elderly population. METHODS: A total of 21 nonsmoking couples participated in a randomized, double-blind, crossover study with two consecutive 48-hour exposures to either particle-filtered or nonfiltered air (2,533-4,058 and 7,718-12,988 particles/cm(3), respectively) in their homes. MEASUREMENTS AND MAIN RESULTS: MVF was assessed noninvasively by measuring digital peripheral artery tone after arm ischemia. Secondary endpoints included hemoglobin, red blood cells, platelet count, coagulation factors, P-selectin, plasma amyloid A, C-reactive protein, fibrinogen, IL-6, tumor necrosis factor-alpha, protein oxidation measured as 2-aminoadipic semialdehyde in plasma, urinary 8-iso-prostaglandin F(2alpha), and blood pressure. Indoor air filtration significantly improved MVF by 8.1% (95% confidence interval, 0.4-16.3%), and the particulate matter (diameter < 2.5 mum) mass of the indoor particles was more important than the total number concentration (10-700 nm) for these effects. MVF was significantly associated with personal exposure to iron, potassium, copper, zinc, arsenic, and lead in the fine fraction. After Bonferroni correction, none of the secondary biomarkers changed significantly. CONCLUSIONS: Reduction of particle exposure by filtration of recirculated indoor air for only 48 hours improved MVF in healthy elderly citizens, suggesting that this may be a feasible way of reducing the risk of cardiovascular disease.

Emission of di-2-ethylhexyl phthalate from PVC flooring into air and uptake in dust: emission and sorption experiments in FLEC and CLIMPAQ.

The emission of di-2-ethylhexyl phthalate (DEHP) from a PVC flooring was studied for up to 472 days in both the FLEC (Field and Laboratory Emission Cell) and the CLIMPAQ (Chamberfor Laboratory Investigations of Materials, Pollution, and Air Quality). The loading of the CLIMPAQs was varied but was constant in the FLECs. The sorption properties of FLEC and CLIMPAQ were investigated using different methods. In addition, the uptake of DEHP by office floor dust on the PVC flooring was studied in CLIMPAQ experiments. The concentration versus time curves in both FLECs and CLIMPAQs increased slowly over about 150 days and reached a quasi-static equilibrium at 1 microg m(-3). The main conclusions were that (i) the emission rate of DEHP was limited by gas-phase mass transport and (ii) the dust layer increased the emission rate by increasing the external concentration gradient above the surface of the PVC. These conclusions were based on the facts that the specific emission rate was inversely proportional to the loading and that the dust had sorbed about four times as much DEHP over a 68-day period as emitted in the gas-phase experiments. About one-half of the emitted DEHP was deposited on the internal surfaces of both the FLEC and the CLIMPAQ.