Isatin-Schiff base functionalized graphene oxide as a highly selective turn-on fluorescent probe for the detection of Pd(II) via photoinduced electron transfer pathway.

We investigated the use of isatin-Schiff base functionalized graphene oxide (ISBGO) as a selective fluorescent chemosensor for the detection of palladium ions. Selectivity tests indicated that over 23 metal ions tested, ISBGO (λex = 340 nm, λem = 504 nm) showed the highest affinity for Pd(II), displaying a 10.1-fold enhancement. Also, interference tests proved that in the presence of both Pd(II) and other metal ions, there was still high fluorescence intensity and no considerable quenching occurred. According to DFT and TD-DFT calculations, photo-induced electron transfer (PET) is responsible for the turn-on response produced by the chemosensor. Coordination of Pd(II) with ISBGO in fact blocks PET from imine nitrogen of 3-iminoindolin-2-one moiety to the benzene ring, which in turn leads to a turn-on response. In addition, Job's plot analysis and Benesi-Hildebrand approach suggest that ISBGO preferably forms a 1:1 complex with Pd(II) with an association constant of 1.020 × 105 M-1. Moreover, FT-IR spectroscopy and DFT study showed that amide oxygen and imine nitrogen of 3-iminoindolin-2-one moiety acted as binding sites of ISBGO. High sensitivity, fast response, great degree of sensitivity, short life time, low detection limit of 32 nM combined with high association constant (Kf) of 1.020 × 105 M-1 and increased fluorescence quantum yield (Φf) of roughly 1.5-fold in the presence of Pd (II), highlight the role of ISBGO as an excellent probe for sensing Pd(II) in aqueous solution.

Copper iodide nanoparticles supported on modified graphene-based nanocomposite catalyzed CO2 conversion into oxazolidinone derivatives.

We report on the preparation of copper iodide nanoparticles (NPs) immobilized on vitamin B3-modified graphene (CuI/GO-VB) nanocomposite and its application for the synthesis of oxazolidinone compounds using a remarkable carboxylative cyclization method via the reaction of arylacetylene, aldehyde and benzylamine derivatives under an atmospheric pressure of CO2 gas. The CuI/GO-VB catalyst was prepared from graphene oxide (GO), vitamin B3 (VB) and CuI using a two-step procedure; firstly graphene-based composite (GO-VB) was synthesized by the reaction of GO and nicotinoyl chloride, followed by the immobilization of CuI NPs on GO-VB. The CuI/GO-VB nanocomposite was fully identified with X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The catalytic performance of the CuI/GO-VB heterogeneous catalyst was investigated in carboxylative cyclization for the synthesis of oxazolidinone compounds under an atmospheric pressure of CO2 gas at 100οC in solvent-, base-, and additive-free conditions; the corresponding oxazolidinone compounds were obtained in 79-94% yield. The hot filtration results indicated that CuI/GO-VB nanocomposite was a heterogeneous catalyst and showed a good reusability for 5 runs without a significant decrease in its catalytic performance.

The association between dietary fats and the incidence risk of cardiovascular outcomes: Tehran Lipid and Glucose Study.

BACKGROUND: The association between dietary fats and the risk of cardiovascular disease (CVD) is under debate. We aimed to determine the potential effects of dietary saturated fats (SFA), mono-unsaturated (MUFA) and poly-unsaturated (PUFA) fatty acids on the occurrence of CVD in an adult Asian population. METHODS: This study was conducted within the framework of the Tehran Lipid and Glucose Study on 2809 CVD-free adults, aged ≥ 19 years. Dietary intakes of fats were estimated using a validated 168-items semi-quantitative food frequency questionnaire, at baseline. Adjusted hazard ratios and 95% confidence intervals of CVD were calculated in tertile categories of dietary fats. The risk of CVD was estimated with multivariable Cox regression for the substitution of total fat or SFA with other macronutrients. RESULTS: During 10.6 years of follow up, the incidence rate of CVD events was 7.1%. Mean (± SD) age of the participants was 39 (± 14) years and 43.9% were men. Total fat, animal and plant sources of fats were not associated with risk of CVD events. No significant associations were found between total SFA, lauric acid, myristic acid, stearic acid, palmitic acid as well as MUFA and PUFA and CVD incidence. Substitutions of total fats or SFA with other macronutrients were not associated with CVD risk. CONCLUSIONS: In this study, no significant associations were found between dietary fats and CVD risk. Considering the emerging body of literature that suggests no association between fats and CVD risk, reconsideration of dietary recommendations regarding low fat diets to prevent CVD, seems to be essential.

Does weight change modify the association between the consumption of sugar-sweetened beverages and 100% fruit juice and the risk of metabolic syndrome?

BACKGROUND & AIMS: This study aimed to determine the prospective relationship between the consumption of sugar-sweetened beverages (SSBs) and 100% fruit juice and metabolic syndrome (MetS) and to investigate whether weight change can modify this association in a representative sample of the population of Tehran, Iran. METHODS: In this 8.9-year follow-up study, the consumption of SSBs and 100% fruit juice by 1915 individuals, who participated in Tehran Lipid and Glucose Study (TLGS), was examined using a validated food frequency questionnaire. The MetS was defined according to the Joint Interim Statement. Participants were categorized as those who lost weight (≥-2%), those with weight stability (-1.9%-1.9%), and those who gained weight (≥2%). The Cox regression model was used to determine the relationship between the consumption of SSBs and 100% fruit juice and the risk of MetS and weight gain ≥2%. Also, the modifying effect of weight change including weight loss, weight stability and weight gain on the relationship between SSBs and 100% fruit juice consumption and the incidence of MetS was assessed. RESULTS: There was no significant association between the consumption of SSBs and the risk of MetS in the crude model; however, after adjustments for confounders, a significant positive association was found between the consumption of SSBs and the risk of MetS (HR: 1.33; 95% CI: 1.07-1.66). Also, no significant association was observed between the consumption of 100% fruit juice and the risk of MetS in the crude model. However, after adjustments for the potential confounders, 100% fruit juice was inversely associated with the MetS risk (HR: 0.78; 95% CI: 0.63-0.95). The consumption of SSBs and 100% fruit juice was positively associated with weight gain (≥2% during the follow-up). Nevertheless, after adjustments for lifestyle and dietary factors, there was no significant association between the consumption of SSBs and weight gain. On the other hand, the consumption of 100% fruit juice was positively associated with the increased risk of weight gain (HR: 1.41; 95% CI: 1.20-1.65). Among participants with weight loss, the first, second and third tertiles of 100% fruit juice reduced the risk of MetS by 29% (HR: 0.71; 95% CI: 0.51-0.99), 47% (HR: 0.53; 95% CI: 0.37-0.75) and 35% (HR: 0.65; 95% CI: 0.46-0.92), respectively. CONCLUSION: Although 100% fruit juice reduced the risk of MetS, its consumption must be limited due to its positive effect on weight gain. On the other hand, the consumption of 100% fruit juice reduced the risk of MetS, depending on the individual's weight change. Also, high consumption of SSBs was associated with the incidence of MetS.

Socioeconomic status and lifestyle factors modifies the association between snack foods intake and incidence of metabolic syndrome.

BACKGROUND: Intake of snack foods has been previously associated with an elevated risk of chronic disease; however, studies on snack foods and metabolic syndrome (MetS) while considering the modifying effect of socioeconomic status (SES) and lifestyle factors on this association are lacking. We aimed to investigate the association between snack foods intake and the MetS risk, and the mediatory effects of SES and lifestyle factors on the forenamed association among adults who participated in the Tehran Lipid and Glucose Study (2006-2018). METHODS: This is a prospective study of 1915 participants (male, 40.5%), aged 19-74 year who were free of MetS at baseline. Dietary intakes were gathered using a validated, semi-quantitative food frequency questionnaire at baseline (2006-2008), and with 3-year intervals afterwards. Alternative approach was used for snack foods from all available questionnaires during follow-up. Snack foods were divided into 4 categories, including total snacks, biscuits and cakes, candies and chocolate, and salty snacks. Total snack foods intake and its subgroup (serving/week) were modeled as tertiles. MetS was diagnosed according to the Joint Interim Statement criteria. Physical activity level (PAL) categorized as low/medium and high levels. Information regarding smoking (Smoker/Non-smoker), education (higher/lower education), and occupation (employed/non-employed) was gathered using questionnaire. The Cox regression was used, regarding interaction between snack foods, SES, and PAL on the MetS risk. RESULTS: A total of 591 incident MetS cases were diagnosed during 8.9 years of follow-up. The median total snack foods intake was 5.2 serving/week (IQR: 3.0-9.1). Total snack foods intake was positively associated with the MetS risk after adjusting for potential confounders (adjusted for age and gender, energy intake, total fiber intake, smoking status, PAL, education levels, family history of diabetes, family history of CVD events, and BMI). After adjustment for confounders, among snacks' subgroups, candies and chocolate intake was positively associated with MetS risk. Moreover, among lower-educated and non-employed participants, candies and chocolate intake was positively associated with the MetS risk, by 38 and 43% respectively. Stratification based on PAL resulted a positive association between intake of total snack foods and candies and chocolates and risk of MetS among participants with low PAL. CONCLUSION: Snack foods, especially candies and chocolate, increased the risk of MetS, among individuals with a low PAL.

Trends in dietary food groups and Dietary Approach to Stop Hypertension (DASH) score among adults: A longitudinal study from the Tehran Lipid and Glucose Study, 2006-2017.

OBJECTIVES: This study aimed to examine the secular trends of dietary food groups and diet quality among adults, overall and by sex, education, and employment status. METHODS: This study was conducted within the framework of the Tehran Lipid and Glucose Study. Demographic and anthropometric measurements were gathered using standard questionnaires. In terms of socioeconomic information, participants were divided into two groups according to their educational level and employment status. The regular dietary intakes of participants were gathered with a validated and reliable food frequency questionnaire over the previous year, and Dietary Approaches to Stop Hypertension scores were computed to evaluate diet quality. Generalized estimating equations were used to assess secular trends in food groups within the four phases. RESULTS: From 2006 to 2017, intake of whole grains, legumes, and nuts and seeds increased, and intake of refined grains, dairy products, and solid fats decreased significantly (P for trend < 0.001). Dietary fruit, vegetable, meat, and soft drink intake did not change significantly. According to socioeconomic groups, meat intake decreased significantly among men, uneducated, and unemployed participants, and fruit intake increased in both women and educated participants. Based on a 40-point scale, the Dietary Approaches to Stop Hypertension score increased from 18.1 ± 0.0 in phase1 to 22.7 ± 0.1 in phase 4 of the Tehran Lipid and Glucose Study (P for trend < 0.001). CONCLUSIONS: Over a decade, in addition to improvements in intake of a number of dietary food groups, the estimated overall diet quality of the study population showed a modest improvement. These findings may determine areas for more attention to improve the overall dietary intake of the population.

Dietary phytochemical index associated with cardiovascular risk factor in patients with type 1 diabetes mellitus.

BACKGROUND: Dietary phytochemical index (DPI) is useful and inexpensive method to identify the role of phytochemicals on cardiovascular disease (CVD) risk factors. This study aimed to assess the relationship between DPI and CVD risk factors in patients with type1 diabetes mellitus. METHODS: A total of 261 participants aged 18-35 years with T1DM were enrolled in this cross-sectional study to assess the relationship between DPI and CVD risk factors. Anthropometric measurements, blood lipids, glucose, and antioxidant level were measured. Food intakes were determined using a food frequency questionnaire to calculate DPI. Logistic regression was used. RESULTS: The mean age of participants was 25 years. After adjustment for potential confounders, participants in the highest tertile of DPI had 88 % lower chance of hyperglycemia (P for trend = 0.020), 81 % lower chance of low high-density lipoprotein cholesterol (HDL-C) (P for trend = 0.030) and 98 % lower chance of high low-density lipoprotein cholesterol to HDL-C ratio (P for tend = 0.040). There were no relationships between DPI and other CVD risk factors. CONCLUSIONS: Although higher intake of phytochemical-rich foods had a beneficial effect on some risk factors of CVD, more studies more studies are warranted to corroborate the present findings.

Secular trend in dietary patterns of Iranian adults from 2006 to 2017: Tehran lipid and glucose study.

BACKGROUND: Based on data regarding nutrition transition in the Middle East and North Africa, this study aim to investigate the general structure and secular trend of dietary patterns reported from the Tehran Lipid and Glucose Study (TLGS) and adherence to these dietary patterns among Iranian population from 2006 till 2017. METHODS: We investigated on four examination waves of TLGS, including wave 1 (2006-2008), wave 2 (2009-2011), wave 3 (2012-2014), and wave 4 (2015-2017), using a validated and reliable food frequency questionnaire. Generalized Estimating Equations was used to assess secular trends in anthropometric, biochemical, and dietary variables across the study period. To identify general structure and secular trend of dietary patterns during each waves, principle component analysis (PCA) and K-mean cluster analysis were used, respectively. RESULTS: After adjusting for potential confounders including age, sex, body mass index, and total energy intake, the carbohydrate and protein intake gradually increased and the total fat intake decreased during study period (P-value< 0.001), although total energy intake remained stable. During the study period, participants consumed noticeably less refined grains, solid fat, dairy products, and simple sugars. Snack and dessert consumption increased and meat intakes showed no significant changes during a decade (all P-values< 0.001). Three dietary patterns extracted using PCA, included: Healthy dietary pattern characterized by higher intakes of vegetable, fruit, dairy products, liquid oil, nuts and seeds, and honey and jam; Western dietary pattern featured by refined grain, solid fat, meat, snack and dessert, potato, and soft drink, and the Mixed dietary pattern, highlighted by tea and coffee, and simple sugar. Based on cluster analysis, 27.8% of participants in wave 4 followed a Western dietary pattern, and 34.1% followed the Mixed dietary pattern. The Healthy dietary pattern was stable among the study population during the last decade. CONCLUSIONS: The structure and the type of foods that participants preferred to eat changed since 2006, a new secular trend in dietary patterns, including a stability of Healthy dietary pattern, a decline of the Western dietary pattern and an increase in the Mixed dietary pattern was obsereved in our investigation.

A Prospective Study of Dietary Meat Intake and Risk of Incident Chronic Kidney Disease.

OBJECTIVE: The aim of the present study was to investigate the association of different meat intake and substitution of them with risk of incident chronic kidney disease (CKD). METHODS: At the baseline, habitual dietary intakes of 4881 participants of the Tehran Lipid and Glucose Study who were free of CKD were assessed by a valid and reliable food-frequency questionnaire. Logistic regression, adjusted for age, sex, smoking, total energy intake, triglycerides, body mass index, physical activity, hypertension, and diabetes, was used to assess the relationship between major protein sources of food (total red meat, unprocessed red meat, and processed red meat) and incident CKD. Odds ratios (ORs) and 95% confidence intervals (CIs) for the CKD were estimated for substituting one serving of total red meat with one serving of low-fat dairy, nuts, whole grains, and legumes. RESULTS: The mean ± standard deviation age of participants was 40.1 ± 12.8 years. After adjustment for confounders, compared with the lowest quartile of total red meat intake, OR of incident CKD in the highest quartile was 1.73 (95% CI: 1.33 to 2.24; P for trend <0.001) in the final model. OR for participants in the highest compared with that in the lowest quartile of processed red meat was 1.99 (95% CI: 2.54 to 2.56; P for trend <0.001). In the substitution analyses, replacing 1 serving of total red meat and processed meat with 1 serving of low-fat dairy, nuts, whole grains, and legumes was associated with a lower risk of incident CKD. CONCLUSIONS: Higher consumption of total red meat and processed meat was associated with increased risk of incident CKD. Furthermore, substitution of total red and processed meat in the diet with other sources of dietary protein was associated with lower CKD risk.

Dietary glycemic index and dietary glycemic load is associated with apelin gene expression in visceral and subcutaneous adipose tissues of adults.

BACKGROUND: Apelin, as an adipokine, plays an important role in the pathogenesis of insulin resistance and type 2 diabetes. This study aimed to determine whether the quality and quantity of dietary carbohydrates were associated with apelin gene expression in subcutaneous and visceral adipose tissues. METHODS: In this cross-sectional study, 102 adults who underwent minor abdominal surgery were selected. Approximately 100 mg of subcutaneous and visceral adipose tissues were collected during the surgery to measure apelin gene expression. Anthropometric measurment, blood samples, and dietary intakes were collected before surgery. The dietary carbohydrate intake, glycemic index (GI), and glycemic load (GL) were determined. RESULTS: The average apelin concentration was 269.6 ± 98.5(pg/mL), and 16.3% of participants were insulin resistant. There was a correlation between insulin (p-value = 0.043), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)(p-value = 0.045) and apelin gene expression in visceral adipose tissue. There was a positive association of apelin gene expression with dietary GI and GL after adjustment for age, sex, and waist circumference in visceral and subcutaneous adipose tissues(p < 0.05). Apelin gene expression in visceral(p = 0.002) and subcutaneous(p = 0.003) adipose tissues was directly associated with foods with a higher GI. There was no association between total carbohydrate intake and apelin gene expression in both visceral and subcutaneous adipose tissues. CONCLUSIONS: Dietary GI and GL, not total carbohydrate intake, were positively associated with apelin gene expression in both visceral and subcutaneous adipose tissues. Future studies are warranted to illustrate the chronic and acute effect of carbohydrate quality on apelin homeostasis.

Association of nuts and unhealthy snacks with subclinical atherosclerosis among children and adolescents with overweight and obesity.

BACKGROUND: The process of atherosclerosis begins early in childhood and usually remains asymptomatic until later in life. Carotid intima-media thickness (cIMT) as a marker of subclinical atherosclerosis could identify early vascular alterations. Unhealthy snacks consumption is associated with obesity and other CVD risk factors in children and adolescents. The aim of this study is to investigate the association of different snack substitution and cIMT among overweight and obesity children and adolescents. METHODS: A total of 339 participants aged 6 to 13 years with the body mass index Z score ≥ 1 based on WHO criteria enrolled in this study. We measured food intakes of participants by validate and reliable food frequency questionnaire (FFQ). Carotid intima media thickness was measured in the common carotid artery with high-resolution ultrasonography. RESULTS: After controlling for confounders, intake of nuts had a negative relationship with cIMT (ß = 0.135 mm P value = 0.009). Moreover, participants in the last tertile of nuts intake had 59% lower risk of high cIMT in comparison with those who consumed less than 0.64 serving/wk./1000Kcal of nuts (P for trend = 0.010). Substituted of nuts intake with sweet unhealthy snacks had a negative relationship with cIMT (ß = 0.15 mm). There was no other significant association between energy-dense nutrient-poor solid snacks and cIMT. CONCLUSIONS: Our findings emphasize the impact of nuts consumption as a healthy snack on subclinical stages atherosclerosis. Clinical trial studies could examine the effect of different kinds of nuts consumption on cIMT and complications of CVD risk factors.

Effectiveness of the national food supplementary program on children growth and nutritional status in Iran.

This study aimed to evaluate the effectiveness of the national food distribution program on the growth and nutritional status of malnourished or growth-retarded children in 2 provinces of Iran. A quasi-experimental design was used for the effectiveness evaluation. Qualitative data were gathered to explain the results. An intervention group consisted of 362 children aged 6-72 months who were under coverage of the program. These children received monthly food as foodstuff, food vouchers, or cash. A comparison group included 409 children aged 6-72 months who were selected from those covered by the Primary Health Care system. Children anthropometric indices were measured at the baseline and also 6 months later. Twelve focus group discussions were held with mothers who had at least 1 child under the coverage of the program. At the end of the study, the mean weight-for-age Z scores, height-for-age Z scores, and weight-for-height Z scores increased compared with the baselines in both groups (p < .001). The differences between 2 groups in weight-for-age Z scores, height-for-age Z scores, and weight-for-height Z scores were not significant at the end of the study (p = .62, p = .91, and p = .94, respectively). According to the mothers' reports, factors affected the program outcome, that is, children anthropometric indices were low income, intrahousehold food sharing, irregular distribution, quantity and quality of the distributed food, and insufficient training. Providing foods for the malnourished children living in low-income families helped to prevent a worsening of their nutritional status; however, it has not been effective in solving the problem, probably due to the weak implementation and lack of empowerment strategies.

Multivalent calix[4]arene-based fluorescent sensor for detecting silver ions in aqueous media and physiological environment.

A new derivative of dipodal 1,3-calix[4]arene-based chemosensor (R), which was containing several binding sites have been synthesized and characterized by NMR, IR and LC-MS spectroscopic methods. The selectivity of Rhas been investigated in aqueous methanol, resulting in fluorescence shift and selective recognition of Ag+ among 20 various alkali, alkaline earth and transition metal ions. Microstructural features of R and its complex with Ag+have been investigated by Atomic Force Microscopy (AFM). AFM images can clearly differentiate R from its complex of Ag+. Moreover; the complicated binding mode of metal-ligand complex has been explored by UV-Vis, LC-MS, FIR, Fluorescence titration, Job's plot method and theoretical approaches. Density functional theory (DFT) method at B3LYP/LANL2DZ level of theory was employed for computational studies. Theoretical calculations revealed that selectivity and specificity of R toward Ag+ could be attributed to structural conformation of 1,3-alternate-calix[4]arene scaffold and molecular electrostatic potential of its surface. Furthermore; the competitive experiments were carried out to test sensor's ability for practical uses. Finally, the efficiency of R in matrix of physiological cations was examined and showed gradual emission enhancement which makes R an ideal candidate for monitoring of Ag+ in physiological environment.

Ultrasound-assisted direct oxidative amidation of benzyl alcohols catalyzed by graphite oxide.

Ultrasound irradiation was successfully applied for the direct oxidative amidation of benzyl alcohols with amines into the corresponding amides using graphite oxide (GO) as an oxidative and reusable solid acid catalyst in acetonitrile as solvent at 50°C under air atmosphere. The direct oxidative amidation of benzyl alcohols takes place under mild conditions yielding the corresponding amides in good to high yields (69-95%) and short reaction times under metal-free conditions.

Sulfonated reduced graphene oxide as a highly efficient catalyst for direct amidation of carboxylic acids with amines using ultrasonic irradiation.

Sulfonated reduced graphene oxide nanosheets (rGO-SO3H) were prepared by grafting sulfonic acid-containing aryl radicals onto chemically reduced graphene oxide (rGO) under sonochemical conditions. rGO-SO3H catalyst was characterized by Fourier-transform infrared (FT-IR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). rGO-SO3H catalyst was successfully applied as a reusable solid acid catalyst for the direct amidation of carboxylic acids with amines into the corresponding amides under ultrasonic irradiation. The direct sonochemical amidation of carboxylic acid takes place under mild conditions affording in good to high yields (56-95%) the corresponding amides in short reaction times.

Ultrasound assisted direct oxidative esterification of aldehydes and alcohols using graphite oxide and Oxone.

A sonochemical procedure for direct oxidative esterification of aldehydes and alcohols using graphite oxide and Oxone in an alcoholic solvent is described. Mild reaction conditions, short reaction times, cost-effectiveness, and facile isolation of the products make the present system as a practical method.

New ZnO nanostructures as non-enzymatic glucose biosensors.

In a new approach, shape controlled synthesis of zinc oxide nanostructures were carried out using a solvothermal route assisted amino acids such as L-Lysine (lysine), L-Cysteine (cysteine) and L-Arginine (arginine) as bifunctional species with (or without) urea or oxalic acid as additives which affect the pH of the reaction. Rod, powder, particle, cube, rock candy-like, sheet, sphere, brain-like, groundnut-like and pussy willow-like morphologies were obtained through the synthetic route. Particle sizes varied from 25 nm to4 µm. To test the application, nine ZnO nanostructures, formulated by multi-walled carbon nanotube (MWCNT) on glassy carbon electrode (GCE) were applied as new nanobiosensors for detecting glucose in a simple and inexpensive way without using any glucose oxidase or nafion. Glucose sensing accomplished in a phosphate buffer solution (PBS, pH=7) for ZnO/MWCNT/GCE samples. Results showed that in this non-enzymatic biosensor system, spherical ZnO obtained from zinc acetate/cycteine/oxalic acid synthetic route has the highest sensitivity of 64.29 µA/cm(2) mM with repeatable results. For the mentioned sensor, no interference observed in the presence of dopamine, uric acid and fructose.