Isothermal Cyclic Conversion of Methane into Methanol over Copper-Exchanged Zeolite at Low Temperature

Direct partial oxidation of methane into methanol is a cornerstone of catalysis. The stepped conversion of methane into methanol currently involves activation at high temperature and reaction with methane at decreased temperature, which limits applicability of the technique. The first implementation of copper-containing zeolites in the production of methanol directly from methane is reported, using molecular oxygen under isothermal conditions at 200 °C. Copper-exchanged zeolite is activated with oxygen, reacts with methane, and is subsequently extracted with steam in a repeated cyclic process. Methanol yield increases with methane pressure, enabling reactivity with less reactive oxidized copper species. It is possible to produce methanol over catalysts that were inactive in prior state of the art systems. Characterization of the activated catalyst at low temperature revealed that the active sites are small clusters of copper, and not necessarily di- or tricopper sites, indicating that catalysts can be designed with greater flexibility than formerly proposed.

Comparison of anti-Mullerian hormone level between uterine artery embolization and myomectomy in uterine fibroma

Background: Uterine fibroma was a general gynecologic condition. When pharmacological therapies fail, surgical interferences such as myomectomy, hysterectomy, or embolization of uterine artery (UAE) are used as that state. This study aimed to compare hormone of anti-Mullerian measure among two methods of UAE, myomectomy into the treatment of uterine fibroma. Material and Method: In this clinical trial held in Imam Reza Hospital of Kermanshah, 40 cases by uterine fibroma were entered into the group of UAE (20 cases) and myomectomy (20 cases). Anti-Mullerian hormone levels were measured twice (ago and later therapeutic interventions) using the Monobinal kit. The information are examined by the SPSS (ver. 20.0) software by applying the Leven's test, paired and independent t-test, Wilcoxon, and Mann-Whitney tests. Results: There is n't matter variation in terms of age between two groups (P> 0.05). Not important variation is recognized regarding anti-Mullerian hormone level before and after six months the medical intervention in either group (P> 0.05). Also, no important variation was detected among the 2 groups in terms of the anti-Mullerian hormone level (P= 0.58). Conclusion: The results obtained demonstrated that where is not statistically important variation among UAE and myomectomy by in terms of anti-Mullerian hormone, which reflects ovarian capacity. Therefore, UAE, which is a less invasive method, can be a suitable substitute for surgical methods in the therapy of significant uterine fibroids between women of the sexual period.

Enterocyte-afferent nerve interactions in dietary fat sensing

The central nervous system (CNS) constantly monitors nutrient availability in the body and, in particular, in the gastrointestinal (GI) tract to regulate nutrient and energy homeostasis. Extrinsic parasympathetic and sympathetic nerves are crucial for CNS nutrient sensing in the GI tract. These extrinsic afferent nerves detect the nature and amount of nutrients present in the GI tract and relay the information to the brain, which controls energy intake and expenditure accordingly. Dietary fat and fatty acids are sensed through various direct and indirect mechanisms. These sensing processes involve the binding of fatty acids to specific G protein-coupled receptors expressed either on the afferent nerve fibres or on the surface of enteroendocrine cells that release gut peptides, which themselves can modulate afferent nerve activity through their cognate receptors or have endocrine effects directly on the brain. Further dietary fat sensing mechanisms that are related to enterocyte fat handling and metabolism involve the release of several possible chemical mediators such as fatty acid ethanolamides or apolipoprotein A-IV. We here present evidence for yet another mechanism that may be based on ketone bodies resulting from enterocyte oxidation of dietary fat-derived fatty acids. The presently available evidence suggests that sympathetic rather than vagal afferents are involved, but further experiments are necessary to critically examine this concept.

High dietary fat intake influences the activation of specific hindbrain and hypothalamic nuclei by the satiety factor oleoylethanolamide

Chronic exposure to a diet rich in fats changes the gastrointestinal milieu and alters responses to several signals involved in the control of food intake. Oleoylethanolamide (OEA) is a gut-derived satiety signal released from enterocytes upon the ingestion of dietary fats. The anorexigenic effect of OEA, which requires intestinal PPAR-alpha receptors and is supposedly mediated by vagal afferents, is associated with the induction of c-fos in several brain areas involved in the control of food intake, such as the nucleus of the solitary tract (NST) and the hypothalamic paraventricular (PVN) and supraoptic nuclei (SON). In the present study we investigated whether the exposure to a high fat diet (HFD) alters the hindbrain and hypothalamic responses to OEA. To this purpose we evaluated the effects of OEA at a dose that reliably inhibits eating (10mg/kg i.p.) on the induction of c-fos in the NST, area postrema (AP), PVN and SON in rats maintained either on standard chow or a HFD. We performed a detailed analysis of the different NST subnuclei activated by i.p. OEA and found that peripheral OEA strongly activates c-fos expression in the AP, NST and in the hypothalamus of both chow and HFD fed rats. The extent of c-fos expression was, however, markedly different between the two groups of rats, with a weaker activation of selected NST subnuclei and stronger activation of the PVN in HFD-fed than in chow-fed rats. HFD-fed rats were also more sensitive to the immediate hypophagic action of OEA than chow-fed rats. These effects may be due to a decreased sensitivity of vagal afferent fibers that might mediate OEA's actions on the brain and/or an altered sensitivity of brain structures to OEA.

Ultra-deep adsorptive desulfurization of a model diesel fuel on regenerable Ni-Cu/γ-Al₂O₃ at low temperatures in absence of hydrogen

A model diesel fuel containing 250 ppmw sulfur (as dibenzothiophene) in n-hexadecane was desulfurized at low temperatures in absence of hydrogen, down to about zero ppmwS on a novel adsorbent of well dispersed 3-12 nm Nix-Cu10-x (x=Ni wt%) nanoparticles formed by impregnation on γ-Al2O3 and reduced in H2 at 275 or 450°C. The sorbents were characterized by XRD, TEM-EDX, FESEM-EDS, H2-TPR, TPO, BJH and BET surface area measurement techniques. Effects of various parameters comprising Cu content, reduction and desulfurization temperatures, inhibition by naphthalene, and regeneration of spent sorbents were investigated. As copper is added to nickel: (a) the sorbent reduction temperature shifts to dramatically lower values, (b) sulfur adsorption capacity of the sorbents at lower reduction and desulfurization temperatures is significantly improved, and when 14 wt% Ni5Cu5 sorbent is added to the fuel, the sulfur content reduces from 250 ppmwS to about zero in less than 1 min, (c) loss of adsorption capacity after the regeneration of the spent sorbent reduced at 275°C is significantly diminished, and (d) the selectivity of the sorbents to dibenzothiophene in the presence of naphthalene is improved. A higher reduction temperature tends to agglomerate nickel nanoparticles and reduce the sulfur adsorption capacity.

Contamination levels and spatial distributions of heavy metals and PAHs in surface sediment of Imam Khomeini Port, Persian Gulf, Iran

Imam Khomeini Port (IKP) is the largest Iranian commercial port. Because of many petrochemical industries and urban areas are located around this port and also having heavy ship traffic, concentrations of PAHs, mercury and other heavy metals were measured as the first time in surface sediment of the jetties. The highest concentrations of PAHs, Hg, Cu, Pb and Fe were recorded at Site 1, located in the vicinity of the petrochemical industrial zone, where ships are repaired. The highest concentration of Zn was found at Site 4, which is the jetty for loading mineral materials. The comparison between measured values in this study and some sediment quality guidelines indicated that the concentrations of mercury and PAHs are much higher than other studies. Also, the ratios of PAHs in the stations showed a mixture of both of pyrolytic and petrogenic sources with a dominance of pyrolytic sources.

Metal concentrations in tissues of two fish species from Qeshm Island, Iran

The purpose of this study was to determine the concentrations of metals, cadmium, chromium, lead and nickel in Liza vaigiensis and Johnius carutta, in order to: compare metal concentrations between two species with different gender, and to determine the significance between metal concentrations in the gill, liver and muscle. The highest mean concentrations of cadmium, chromium, lead and nickel in different tissues of these two fish species were found in the liver of L. vaigiensis at 0.68, 0.83, 0.37 and 1.42 μg g(-1), respectively; while the lowest mean concentrations of cadmium, chromium, lead and nickel were observed in the muscle of J. carutta at 0.16, 0.16, 0.03 and 0.29 μg g(-1), respectively. The results showed that the metal concentrations in both species were higher in the females than in the males (except chromium in gill and cadmium in muscle of J. carutta). Also, the results indicated that the metal concentrations were different among fish tissues (one-way ANOVA, p < 0.001), but there was no difference (except lead in gills of J. carutta) between sex (male vs. female).

The familial aggregation of cigarette smoking in kish, iran

BACKGROUND

Based on WHO reports, smoking is an epidemic in developing countries. One of important issues about this behavior is its distribution pattern in family members. The main purpose of this study was to evaluate if cigarette smoking had a tendency to cluster or aggregate in the families and what the determinants were.

METHODS

Using a multi-stage random cluster sampling approach, a household survey was conducted in Kish Island in 2009. We used the Alternating Logistic Regressions algorithm to model to show the familial aggregation.

RESULTS

The odds ratio for the aggregation of cigarette smoking between family members was 1.63 (1.29-2.06) which increased to 1.96 (1.50-2.55) after adjustment for demographic factors. There was no significant correlation between siblings' cigarette smoking nor was between spouses but the pairwise odds ratio for parents offspring was significant. In other words, cigarette smoking in at least one of the parents increased the odds of being a smoker in offspring significantly.

CONCLUSION

The study showed that the smoking behavior aggregated in families significantly. The inter-parent offspring aggregation was the main component of the familial aggregation. Higher education and age-gender interaction were determinants of smoking in the families. The programs for prevention and cessation of this behavior in the community might be more successful if they were designed in a family-based rather than an individual-based approach.

Effect of group reminiscence therapy on depression in older adults attending a day centre in Shiraz, southern Islamic Republic of Iran

The aim of this study was to examine the effectiveness of group reminiscence therapy on depression symptoms among elderly people attending a day centre in Shiraz, Islamic Republic of Iran. A sample of 49 people aged 60+ years participated in 6 group reminiscence sessions that were held twice weekly for a 3-week period and completed a Farsi version of the 15-item geriatric depression scale. Mean depression scores decreased significantly from 8.18 (SD 1.20) before the intervention to 6.73 (SD 1.20) immediately after it and 7.55 (SD 1.19) 1 month after the intervention. When analysed by demographic characteristics only marital status showed a statistically significant difference in depression scores comparing before and after the intervention.