Creep failure of hierarchical materials.

Creep failure of hierarchical materials is investigated by simulation of beam network models. Such models are idealizations of hierarchical fibrous materials where bundles of load-carrying fibers are held together by multi-level (hierarchical) cross-links. Failure of individual beams is assumed to be governed by stress-assisted thermal activation over local barriers, and beam stresses are computed by solving the global balance equations of linear and angular momentum across the network. Disorder is mimicked by a statistical distribution of barrier heights. Both initially intact samples and samples containing side notches of various length are considered. Samples with hierarchical cross-link patterns are simulated alongside reference samples where cross-links are placed randomly without hierarchical organization. The results demonstrate that hierarchical patterning may strongly increase creep strain and creep lifetime while reducing the lifetime variation. This is due to the fact that hierarchical patterning induces a failure mode that differs significantly from the standard scenario of failure by nucleation and growth of a critical crack. Characterization of this failure mode demonstrates good agreement between the present simulations and experimental findings on hierarchically patterned paper sheets.

Assessment of different dietary alfalfa hay to alfalfa silage ratios for dromedary camel feeding.

Two in vivo experiments studied the effects of different alfalfa hay (AH) to alfalfa silage (AS) ratios including 100:0 (AH100), 50:50 (AH50:AS50) and 0:100 (AS100) in total mixed rations (TMR) of dromedary camels. In experiment (Exp.) 1, a total of 18 multiparous Baluchi dairy camel [100 ± 5 days in milk (DIM); 3.65 ± 0.539 kg milk yield] were randomly allocated to one of the three groups (n = 6) for 42 d of experimental period. Dry matter intake (DMI) and milk yield were recorded daily, and blood samples were collected on days 0, 21 and 42. In Exp. 2, 18 male Baluchi camel calves [275 ± 14 days of old; 105 ± 8 kg BW] were housed in individual shaded pens for 150 days. DMI was recorded daily and individual weights of camels were recorded monthly. Blood samples were collected on days 0, 75 and 150. In Exp.1, feeding different dietary AH:AS ratios altered neither DMI (p = 0.351) nor milk yield (p = 0.667). Of all milk components, only the milk urea nitrogen (MUN) was increased (p = 0.015) by AS feeding (both AH50:AS50 and/or AS100). AS feeding tended to increase AST (p = 0.099) and ALT (p = 0.092) levels in lactating camels. In Exp. 2, DMI (p = 0.845), average daily gain (ADG; p = 0.092) and return per kg BW gain (p = 0.710) of silage-fed camels were similar to those of hay-fed group. The plasma concentration of BUN (p = 0.014) and AST (p = 0.014) were increased in camels fed AS100. Overall, the results suggest that both AS and/or AH could be used in dromedary camel diets based on the climatic condition, season and available facilities; however, the long-term use of AS (as sole forage) should done with caution due to the potential risk of impaired liver function. Further studies needed to explore the impact of hay versus silage feeding on digestibility, rumen function and nitrogen pollution in camel feeding.

The Inclusion of Alhagi maurorum in Growing Camel Diet: Effect on Performance, Liver-Related Blood Metabolites, and Antioxidant Status.

This study determined the effect of dietary inclusion of camelthron [Alhagi maurorum (AM)] on the performance, blood metabolites, and antioxidant status of growing camels. A total of 18 Sindhi camel calves of 9-10 months of age and 115 ± 7 kg body weight (BW) were randomly assigned to three diets (with a forage:concentrate ratio of 50:50) that were formulated by partial and total substitution of alfalfa hay with AM as follows: (1) diet without AM (control), (2) diet containing 25% of AM (AM-25), and (3) diet containing 50% of AM (AM-50) (dry matter basis) for 150 days. Dry matter intake (DMI) was recorded daily. The camels were weighed individually on days 0, 30, 60, 90, 120, and 150. Blood samples were collected on days 0, 75, and 150. DMI was increased (p = 0.004) with AM-50 feeding followed by AM-25. Total weight gain (p = 0.048) and average daily gain (ADG) (p = 0.043) decreased with AM-50; however, no differences were observed between the AM-25 and CON groups. Feed cost per kg BW gain tended to decrease (p = 0.092) and return per kg BW gain tended to increase (p = 0.087) by AM feeding. The plasma triglycerides (TGs) (p = 0.046) and cholesterol (CHOL) (p = 0.025) concentration were reduced with AM inclusion. Additionally, the AM50-fed camels showed the lowest concentration of aspartate aminotransferase (AST) (p = 0.008) and alanine aminotransferase (ALT) (p = 0.0036), followed by AM-25. The plasma malondialdehyde (MDA) was depressed (p = 0.037) and total antioxidant capacity (TAC) was enhanced (p = 0.016) with both the AM-25 and AM-50. Moreover, feeding the AM containing diets led to higher (p = 0.004) glutathione peroxidase (GPx) along with a tendency for superoxide dismutase (SOD) (p = 0.075) and catalase (CAT) (p = 0.094). Overall, feeding camels with AM for up to 25% of their dry matter (DM) diet positively influenced the antioxidant status without severe deleterious effects on performance.

The effect of melatonin supplementation on liver indices in patients with non-alcoholic fatty liver disease: A systematic review and meta-analysis of randomized clinical trials.

Several randomized clinical trials (RCTs) evaluated the effect of melatonin supplementation on liver enzymes in patients with non-alcoholic fatty liver disease (NAFLD) and reported conflicting results. To meet these discrepancies, a meta-analysis was conducted to evaluate the eff ;ect of melatonin on liver indices in patients with NAFLD. To collect the required data, a thorough search was conducted through Web of science, Pubmed, Cochrane database, Embase, Google Scholar, ProQuest, and Scopus databases. The aim was to find clinical trials over the effect of melatonin supplementation on liver indices up to 16 May 2019. As a result, five eligible articles were selected and analysed in this meta-analysis using a fixed-effects model. Heterogeneity test was performed by I2 statistics and Cochrane Q test. The results showed that melatonin had a significant effect on aspartate aminoteransferase (AST) (WMD = 2.29, [95 %CI: 1.14, 3.43] IU/L, p = <0.001), alkaline phosphatase (ALP) (WMD = -8.40, [95 %CI -11.33, -5.48] IU/L, p < 0.001), and gamma-glutamyltransferase (GGT) (WMD = -33.37, [95 %CI: -37.24, -29.49] IU/L, p= < 0.001). Melatonin had no significant effect on alanine aminotransferase (ALT) regarding the overall effect size. Based on this meta-analysis, melatonin supplementation can improve liver indices. However, more RCTs are required with larger sample sizes and better control of confounding variables such as weight, body mass index, and gender to determine the effect of melatonin on patients with non-alcoholic fatty acid disease.

Socioeconomic - related inequalities in overweight and obesity: findings from the PERSIAN cohort study.

BACKGROUND: Overweight and obesity are major health concerns worldwide, with adverse health consequences during the life span. This study measured socioeconomic inequality in overweight and obesity among Iranian adults. METHODS: Data were extracted from 129,257 Iranian adults (aged 35 years and older) participated in the Prospective Epidemiologic Research Studies in IrAN (PERSIAN) in 14 provinces of Iran in 2014. Socioeconomic-related inequality in overweight and obesity was estimated using the Concentration Index (Cn). The Cn further decomposed to find factors explaining the variability within the Socioeconomic related inequality in overweight and obesity. RESULTS: Of the total number of participants, 1.98, 26.82, 40.76 and 30.43% had underweight, normal weight, overweight and obesity respectively. The age-and sex standardized prevalence of obesity was higher in females than males (39.85% vs 18.79%). People with high socioeconomic status (SES) had a 39 and 15% higher chance of being overweight and obese than low SES people, respectively. The positive value of Cn suggested a higher concentration of overweight (0.081, 95% confidence interval [CI]; 0.074-0.087) and obesity (0.027, 95% CI; 0.021-0.034) among groups with high SES. There was a wide variation in socioeconomic-related inequality in overweight and obesity rate across 14 provinces. The decomposition results suggested that SES factor itself explained 66.77 and 89.07% of the observed socioeconomic inequalities in overweight and obesity among Iranian adults respectively. Following SES, province of residence, physical activity, using hookah and smoking were the major contributors to the concentration of overweight and obesity among the rich. CONCLUSIONS: Overall, we found that overweight and obesity is concentrated among high SES people in the study population. . Accordingly, it seems that intersectional actions should be taken to control and prevent overweight and obesity among higher socioeconomic groups.

An evaluation of hospital admission respiratory disease attributed to sulfur dioxide ambient concentration in Ahvaz from 2011 through 2013.

There is no doubt that air pollutants have adverse impacts on human health. The main objective of this study was to evaluate hospital admission respiratory disease (HARD) attributed to sulfur dioxide levels in Ahvaz during three successive years. Data was taken from Iranian Environmental Protection Agency (EPA). The AirQ2,2,3 model is used to quantify the impact of SO2 on inhabitants of Ahvaz and in terms of hospital admission respiratory diseases. This is a kind of statistical model which is based on some epidemiological indices such as relative risk, baseline incidence, and attributable proportion. Sampling was already performed for 24 h in four stations during 2011-2013. Four stations are good representative for residential, high traffic, industry, and background sites which cover the whole area of the Ahvaz city. Regarding to gravimetric scale, raw data of sulfur dioxide was processed using Excel software. Encoding, filtering, and processing were conducted to prepare input file for the Air Q2,2,3 model. After running model, outputs presented in term of hospital admissions respiratory cases. Based on our result, the highest mean and maximum of seasonal and annual levels for sulfur dioxide were observed in 2013. We concluded that obnoxious quality of fuel and some deficiencies in maintenance and operation of industries lead to worse quality of ambient air especially in 2013. Cumulative cases of HARD attributed to sulfur dioxide level at central of relative risk (RR) were estimated 24, 25, and 30 persons for 2011, 2012, and 2013, respectively. The finding of this study showed that total mean of sulfur dioxide was higher than standard concentration. We also noticed that wintertime concentrations of sulfur dioxide during three successive years were higher than of those levels in summer.