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

Characterization of Bacillus Isolates from the Rhizosphere of Tomato Suppressing Fusarium Wilt Disease

Fusarium wilt of tomato is one of the most prevalent and economically important diseases of tomato worldwide especially in tropical regions. The aims of the present study were to isolate and characterize Bacillus bacteria from tomato rhizospheric soil of various regions in Iran and determine the isolates that exhibit high levels of antagonistic efficiency against tomato Fusarium wilt pathogen, Fusarium oxysporum f. sp. lycopersici (Fol) and growth promotion activity. In this study, 303 Bacillus isolates were obtained from tomato rhizospheric soil. Dual culture and volatile metabolite tests were used to screen for antagonism of Bacillus isolates against Fol. Among them, 20 isolates were found to inhibit pathogen growth by 67.77% and 33.33% in dual culture and volatile metabolite tests, respectively. Based on the results of physiological tests and 16S rRNA and gyrA gene sequence analysis of 20 effective isolates, 11, seven and two isolates were identified as B. subtilis, B. velezensis and B. cereus, respectively. The results of greenhouse assessment showed that KR1-2, KR2-7 and A2-9 isolates which were characterized as Bacillus subtilis, reduced the disease index to 16.67% and promoted the plant growth by 80%. These isolates may serve as potential promising biocontrol agents against Fusarium wilt of tomato

Associations between Western and Mediterranean-type dietary patterns and anxiety and stress

In this study we investigated the relationship between dietary patterns and anxiety and stress in adults living in Shiraz, Iran. In a cross-sectional design, 416 subjects (180 men and 236 women) aged 20 to 50 years were selected by stratified multistage random sampling. Dietary intakes were assessed using a semi-quantitative food frequency questionnaire (FFQ). Mental health information was collected by depression, anxiety and stress scale (DASS) questionnaire. Three major dietary patterns were extracted by factor analysis: vegetable, Western, and Mediterraneantype dietary patterns. Regression analysis showed a strong positive association between Western dietary pattern and anxiety (β=0.66; 95% CI: 0.03, 1.28), and stress (β=0.84; 95% CI: 0.1, 1.57). Also, there was an inverse association between Mediterranean-type dietary pattern and anxiety (β= ‒0.81; 95% CI: ‒1.43, ‒0.19). These associations remained statistically significant even after adjustments for demographic characteristics, physical activity, smoking, body mass index, and energy intake. No association was found between vegetable dietary pattern and any of the assessed psychiatric disorders

Factors affecting ethical behavior in pediatric occupational therapy: A qualitative study

Background: It is the responsibility of each occupational therapist to always act ethically and professionally in a clinical setting. However, there is little information available concerning the factors influencing ethical behavior of occupational therapists at work. Since no study has been conducted in Iran on this topic, this qualitative study aimed to identify the factors influencing ethical behavior of pediatric occupational therapists. Methods: Twelve pediatric occupational therapists participated in this study. The sampling was purposeful, and the interviews continued until reaching data saturation. All interviews were recorded and transcribed. The data were analyzed by qualitative content analysis, and the ethics of qualitative research was considered. Results: The factors influencing ethical behavior were classified into four main categories including organizational factors, therapist related factors, client's family issues, and social factors. Conclusion: This study identified numerous factors influencing the ethical behavior of pediatric occupational therapists that could be used to train occupational therapists, human resources managers, professional policy makers, and could also be used to conduct future researches, and produce tools

Study of genetic diversity of wild Caspian trout Salmo trutta caspius in the Sardabrud and Astara Rivers, using D-Loop region sequencing

In this study the genetic diversity of wild Caspian trout (Salmo trutta caspius) in the Sardabroud and Astara Rivers was evaluated using D-Loop region sequencing. For this purpose, 35 specimens of adult Caspian brown trout were collected from these rivers in the Mazandarn and Gilan Provinces in fall and winter 2011. Approximately 3-5 g of soft and fresh fin tissue was isolated and fixed in ethanol 96% and then transferred to the Caspian Sea Ecology Research Center Genetics Laboratory in Sari, Iran. Genomic DNA from the samples was extracted using Ammonium Acetate Method. The quality and quantity of the extracted DNA were assessed by spectrophotometer and agarose gel (1%) electrophoresis. Polymerase Chain Reaction (PCR) was performed on the target DNA using a primers sequence D-Loop region of mtDNA molecule. Then the product was purified and DNA sequencing was carried out using chain termination method. The D-Loop region of Caspian trout contained 654 bp. Data were analyzed using Bio-Edit, DnaSP, Arlequin and Mega software. 20 and 15 haplotypes was observed in Sardabrud and Astara River. The DNA sequence of one of them was recorded in Gene Bank with numbers KC991027 and KF015727. 223 and 240 polymorphic loci were detected in Sardabrud and Astara River that all of them were out of Hardy-Weinberg equilibrium (p<0.05). Average nucleotide and haplotype diversity were 0.127±0.067, 1.000±0.005 in Sardabrud River and 0.118±0.063 and 1.000±0.005 in Astara River

Which one is better: presentation-based or content-based math search?

Mathematical content is a valuable information source and retrieving this content has become an important issue. This paper compares two searching strategies for math expressions: presentation-based and content-based approaches. Presentation-based search uses state-of-the-art math search system while content-based search uses semantic enrichment of math expressions to convert math expressions into their content forms and searching is done using these content-based expressions. By considering the meaning of math expressions, the quality of search system is improved over presentation-based systems

Real-time Measurement of Stress and Damage Evolution During Initial Lithiation of Crystalline Silicon

Crystalline to amorphous phase transformation during initial lithiation in (100) silicon-wafers is studied in an electrochemical cell with lithium metal as the counter and reference electrode. It is demonstrated that severe stress jumps across the phase boundary lead to fracture and damage, which is an essential consideration in designing silicon based anodes for lithium ion batteries. During initial lithiation, a moving phase boundary advances into the wafer starting from the surface facing the lithium electrode, transforming crystalline silicon into amorphous LixSi. The resulting biaxial compressive stress in the amorphous layer is measured in situ and it was observed to be ca. 0.5 GPa. HRTEM images reveal that the crystalline-amorphous phase boundary is very sharp, with a thickness of ~ 1 nm. Upon delithiation, the stress rapidly reverses, becomes tensile and the amorphous layer begins to deform plastically at around 0.5 GPa. With continued delithiation, the yield stress increases in magnitude, culminating in sudden fracture of the amorphous layer into micro-fragments and the cracks extend into the underlying crystalline silicon.Comment: 12 pages, 5 figure

Facilitators of implementing occupation based practice among Iranian occupational therapists: A qualitative study

Background: The Occupation-Based Practice (OBP) is a central core of occupational therapy (OT).It refers to using a meaningful occupation based on the client's interests, needs, health and participation in daily life. This study aimed to explore the facilitators of implementing OBP among Iranian occupational therapists. Methods: Fourteen occupational therapists participated in this study. Data were collected through semi-structured interviews, and the sampling method was purposeful. The interviews were continued until data saturation was reached, and data were recorded and transcribed verbatim. Data were analyzed through qualitative content analysis using constant comparative analysis. Results: Our analysis explored two themes: Factors attributed to context, and factors attributed to therapists. The first theme consisted of three subthemes: Educational programs of OT department, public information about OBP and clinical setting compatible with OBP. The second theme also contained three subthemes including: Positive attitude regarding effectiveness of OBP, emphasis on client- centered and family- centered practice and convincing the clients to utilize OBP. Conclusion: The facilitators of implementing OBP are attributed to factors internal to the therapists as well as to issues in the external environment and context. Understanding these factors will help occupational therapists, OT educational staff, administrators and rehabilitation team members to facilitate the implementation of OBP