Simultaneous Determination of Nitrite and Nitrate in Milk Samples by Ion Chromatography Method and Estimation of Dietary Intake

The presence of nitrate and nitrite in foods may be considered hazardous after ingestion in the gastrointestinal tract due to their reaction with naturally occurred secondary amines to form potentially carcinogenic nitrosamines. Due to this fact, a new method was developed in this study for the simultaneous determination of nitrite and nitrate in milk samples using by ion chromatography. Proposed mobile phase composed of sodium hydrogen carbonate and sodium carbonate (1.0 and 3.2 mmol/L) with a flow rate of 0.7 ml/min. The average recoveries for nitrate and nitrite were higher than 86 and 88, respectively. The limit of detection for nitrate and nitrite were 0.24 and 0.09 mg/L, respectively. The results of 102 real milk samples showed nitrate was found in all of the samples (100) with a mean of 34 ± 11 mg/L, while nitrite was found in none of the samples. The mean intake of nitrate in all age groups was lower than World Health Organization guideline. The present assessment concludes that the maximum contaminant level was equal to 82.8 mg/L nitrate. This method was fast, sensitive and accurate and is capable of being an alternative method in food control laboratories for investigation of nitrite and nitrate content. This is the first study of the determination and survey of nitrite and nitrate and exposure assessment of the Iranian population to nitrite and nitrate level in milk, which was widely used in infants and adolescents as one of the basic food components. Copyright © Taylor & Francis Group, LLC

Electrophysiological and molecular mechanisms of protection by iron sucrose against phosphine-induced cardiotoxicity: A time course study

The present study was designed for determining the exact mechanism of cytotoxic action of aluminum phosphide (AlP) in the presence of iron sucrose as the proposed antidote. Rats received AlP (12 mg/kg) and iron sucrose (5-30 mg/kg) in various sets and were connected to cardiovascular monitoring device. After identification of optimum doses of AlP and iron sucrose, rats taken in 18 groups received AlP (6 mg/kg) and iron sucrose (10 mg/kg), treated at six different time points, and then their hearts were surgically removed and used for evaluating a series of mitochondrial parameters, including cell lipid peroxidation, antioxidant power, mitochondrial complex activity, ADP/ATP ratio and process of apoptosis. ECG changes of AlP poisoning, including QRS, QT, P-R, ST, BP and HR were ameliorated by iron sucrose (10 mg/kg) treatment. AlP initiated its toxicity in the heart mitochondria through reducing mitochondrial complexes (II, IV and V), which was followed by increasing lipid peroxidation and the ADP/ATP ratio and declining mitochondrial membrane integrity that ultimately resulted in cell death. AlP in acute exposure (6 mg/kg) resulted in an increase in hydroxyl radicals and lipid peroxidation in a time-dependent fashion, suggesting an interaction of delivering electrons of phosphine with mitochondrial respiratory chain and oxidative stress. Iron sucrose, as an electron receiver, can compete with mitochondrial respiratory chain complexes and divert electrons to another pathway. The present findings supported the idea that iron sucrose could normalize the activity of mitochondrial electron transfer chain and cellular ATP level as vital factors for cell escaping from AlP poisoning. © 2015 Informa Healthcare USA, Inc. All rights reserved

Evaluation of Different Best Management Practices for Erosion Control on Machine Operating Trails

Ground-based mechanized forest operations often lead to increased runoff and soil loss on unbound forest roads and machine operating trails, which in turn can impede the technical trafficability of machines and cause negative impacts on the environment. The aim of this study was to evaluate the effectiveness of three Best Management Practice (BMP) treatments used to control erosion occurring on machine operating trails. The treatments included water bar, water bar and hardwood brush (H-brush), and water bar and softwood brush (S-brush). For a more comprehensive assessment of both brush treatments, two levels of brush thickness were tested; 0.5 m and 1.0 m. Results indicate that the most effective BMP treatments were the water bar and softwood brush followed by the water bar and hardwood brush and finally the least effective was the water bar. The average runoff rates and soil loss from the machine operating trails with the water bar treatment (52.64 l per plot, 8.49 g m-2) were higher than runoff and soil loss at the trails protected with hardwood brush (23.75 l per plot, 4.5 g m-2), and the trails protected by the hardwood brush had higher runoff and soil loss compared to trails covered by softwood brush (15.83 l per plot, 2.98 g m-2). Furthermore, results of this study showed that regardless of the treatment, the amount of runoff and soil loss decreased consistently as the thickness of the brush mat increased. Overall, erosion control techniques similar to either H-brush or S-brush that provide direct soil coverage should be used for erosion control, and final selection should be based on costs, availability of material, or landowner objectives

Comparison of Sampling Methods Used to Evaluate Forest Soil Bulk Density

The objective of this study was to compare forest soil bulk density values obtained through conventional sampling methods such as the volumetric ring (VR: diameter 5 cm, length 10 cm) and paraffin sealed clod (PSC), with a variation of the VR, where rectangular boxes (RB) of four different dimensions were used. Sampling transects were established on a machine operating trail located in a beech (Fagus orientalis Lipsky) stand in Northern Iran. At each transect, three soil samples were collected at three different locations. Samples from different methods were spaced by a 50 cm distance to avoid direct interactions. The soil class of our study area was Combisols according to the WRB classification with a clay texture. Soil bulk density differed significantly between the three sampling methods. The lowest values were obtained with the RB (average 1.25 g cm-3), followed by the VR (average 1.40 g cm-3), and lastly the PSC (average 1.52 g cm-3). The values obtained with four variations of the RB method ranged from 1.22 to 1.28 g cm-3 and were not found significantly different. When soil bulk density was calculated after the removal of the weight and volume of roots included in the samples, the values were determined to be higher than before but with the same range of magnitude. The lowest coefficient of variation was found for RB4 (CV=2.3%), while the highest values were observed for VR and RB1 (CV=5.7%)

Impact assessment of skidding extraction: Effects on physical and chemical properties of forest soils and on maple seedling growing along the skid trail

Several studies investigated soil disturbances caused on skid trails by forest logging. However, there is still a lack of knowledge about the severity and the distance of disturbances along both sides from the trails. The aims of this study were: i) to investigate the changes in physical and chemical properties of soil along the sides of skidding trails; ii) to measure the effects of soil compaction on of maple seedlings growth. Two levels of trail gradient ( < 20% and > 20 %), four levels of traffic frequency (3, 8, 15, and 30 passes) and four distance buffer strip zones (0.5 m intervals from 0 to 2 m in distance) on both sides of skid trail edges were analyzed. Each treatment included three replicate plots. In order to investigate the effect of compaction on seedlings emergence and growth, maple seeds were sown after logging. The results highlighted significant changes in physical and chemical properties of soil for each traffic frequency in the closest buffer strip (from 0 to 0.5 m from the skid trail edges). The largest changes in soil properties were identified at 0.5 m distance zones for a slope gradient > 20% after 3, 8, 15, and 30 skidding cycles. The highest changes were recorded on slope category > 20%. The higher the soil compaction the lower the germination rate, root length, and stem height of seedlings

Molecular and biochemical evidence on the protection of cardiomyocytes from phosphine-induced oxidative stress, mitochondrial dysfunction and apoptosis by acetyl-l-carnitine

The aim of the present study was to investigate the efficacy of acetyl-l-carnitine (ALCAR) on pathologic changes of mitochondrial respiratory chain activity, ATP production, oxidative stress, and cellular apoptosis/necrosis induced by aluminum phosphide (AlP) poisoning. The study groups included: the Sham that received almond oil only; the AlP that received oral LD50 dose of aluminum; the AC-100, AC-200, and AC-300 which received concurrent oral LD50 dose of AlP and single 100, 200, and 300mg/kg of ALCAR by intraperitoneal injection. After 24h, the rats were sacrificed; the heart and blood sample were taken for measurement of biochemical and mitochondrial factors. The results specified that ALCAR significantly attenuated the oxidative stress (elevated ROS and plasma iron levels) caused by AlP poisoning. ALCAR also increased the activity of cytochrome oxidase, which in turn amplified ATP production. Furthermore, flow cytometric assays and caspase activity indicated that ALCAR prohibited AlP-induced apoptosis in cardiomyocytes. © 2015 Elsevier B.V.

The cooling effect of large-scale urban parks on surrounding area thermal comfort

This empirical study investigates large urban park cooling effects on the thermal comfort of occupants in the vicinity of the main central park, located in Madrid, Spain. Data were gathered during hot summer days, using mobile observations and a questionnaire. The results showed that the cooling effect of this urban park of 125 ha area at a distance of 150 m could reduce air temperatures by an average of 0.63 °C and 1.28 °C for distances of 380 m and 665 meters from the park. Moreover, the degree of the physiological equivalent temperature (PET) index at a distance of 150 meters from the park is on average 2 °C PET and 2.3 °C PET less compared to distances of 380 m and 665 m, respectively. Considering the distance from the park, the correlation between occupant perceived thermal comfort (PTC) and PET is inverse. That is, augmenting the distance from the park increases PET, while the extent of PTC reduces accordingly. The correlation between these two factors at the nearest and furthest distances from the park is meaningful (p-value < 0.05). The results also showed that large-scale urban parks generally play a significant part in creating a cognitive state of high-perceived thermal comfort spaces for residents

Molecular characterization of carbapenem-resistant acinetobacter baumannii isolated from pediatric burns patients in an Iranian hospital

Purpose: To survey the molecular characteristics of imipenem-resistant Acinetobacter baumannii obtained from pediatric burns patients in a teaching hospital in Tehran, Iran. Methods: Over a 10-month period, 73 non-duplicate A. baumannii strains were collected from pediatric burns patients admitted to Motahari Burn and Reconstruction Center, Tehran, Iran. The resistance profile of several antimicrobials was determined. Metallo-β-lactamase (MBL)-producing isolates were identified using double-disk synergy and an MBL E-test. Polymerase chain reaction (PCR) was carried out to detect the following β-lactamase-encoding elements: blaVIM, blaIMP, blaSIM, blaSPM, blaGIM, blaNDM, blaAIM, blaDIM, blaKPC, blaOXA-23/24/51, and blaOXA-58. The types of integrons were also identified using PCR. Results: Out of the 73 collected strains, 92.4 and 38.3 of the isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR), respectively. Colistin was the most effective antibiotic. It was found that 94.5 of the strains were resistant to imipenem, as determined both by disk agar diffusion and MIC E-test methods. Based on double disk synergy and E-test, 78.1 and 83.5 of the isolates, respectively, were MBL producers. The prevalence of blaOXA-23 and blaOXA-24 were 75.4 and 39.1 , respectively. The results also indicate that 62.3, 30.4, and 4.3 of the isolates were positive for blaVIM, blaIMP and blaNDM genes, respectively. Furthermore, 16.4, 76.1, and 7.5 of the isolates carried intI, intII, and intIII genes, respectively. Conclusion: The increased frequency of carbapenem-resistant A. baumannii in burns cases underlines the importance of choosing an appropriate antibacterial regimen based on antibiotic susceptibility profile. Rapid identification of carbapenemase-producing strains would be helpful for selecting suitable antimicrobial therapy and preventing further spread of their encoding genes. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria

Effect of logging wounds on diameter growth of beech (Fagus orientalis Lipsky) trees following selection cutting in Caspian forests of Iran

Background Logging damage to residual trees during selection cutting may lead to serious economic losses in terms of both timber quality and diameter growth reduction. In this study, we investigated the effect of logging operations on residual tree damage and the consequence of injuries on diameter growth in an uneven-aged mixed forest dominated by beech (Fagus orientalis Lipsky)