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Repeated acute stress modulates hepatic inflammation and markers of macrophage polarisation in the rat
No full textBidirectional communication between the neuroendocrine stress and immune systems permits classically anti-inflammatory glucocorticoids to exert pro-inflammatory effects in specific cells and tissues. Liver macrophages/Kupffer cells play a crucial role in initiating inflammatory cascades mediated by the release of pro-inflammatory cytokines following tissue injury. However, the effects of repeated acute psychological stress on hepatic inflammatory phenotype and macrophage activation state remains poorly understood. We have utilised a model of repeated acute stress in rodents to observe the changes in hepatic inflammatory phenotype, including anti-inflammatory vitamin D status, in addition to examining markers of classically and alternatively-activated macrophages. Male Wistar rats were subjected to control conditions or 6\ua0h of restraint stress applied for 1 or 3 days (n\ua0=\ua08 per group) after which plasma concentrations of stress hormone, enzymes associated with liver damage, and vitamin D status were examined, in addition to hepatic expression of pro- and anti-inflammatory markers. Stress increased glucocorticoids and active vitamin D levels in addition to expression of glucocorticoid alpha/beta receptor, whilst changes in circulating hepatic enzymes indicated sustained liver damage. A pro-inflammatory response was observed in liver tissues following stress, and inducible nitric oxide synthase being observed within hepatic macrophage/Kupffer cells. Together, this suggests that stress preferentially induces a pro-inflammatory response in the liver
Hot tensile deformation behavior of extruded LAZ532 alloy with heterostructure
No full textHot tensile test was performed at deformation conditions of 150–°C300 °C and 8.33 × 10 s~1.67 × 10 s, respectively, to systematically study the microstructure development and deformation mechanism of extruded Mg–5Li–3Al–2Zn (LAZ532) alloy with a heterostructure of both the fibrous extrusion zones (FEZs) and non-fibrous extrusion zones (non-FEZs) coexisted. The results showed that the peak stresses decreased gradually, while the fracture strains increased gradually with the decrease of strain rates or the increase of deformation temperatures, and the alloy exhibited superplastic characteristics at deformation conditions of 300 °C and 8.33 × 10 s~1.67 × 10 s. By microstructure observation, the alloy showed that in the initial deformation stage, the deformation of the grains in the FEZs was prior to that in the non-FEZs. In the middle deformation stage, the deformation of the grains in the FEZs was dominated by intragranular slip and accompanied with grain boundary slip (GBS), while the deformation of the grains in the non-FEZs was dominated by GBS and accompanied with intragranular slip. In the later deformation stage, the continuous dynamic recrystallization (CDRX) generated in the coarse lamellar grains in the FEZs due to dislocation pile-up, in contrast, the discontinuous dynamic recrystallization (DDRX) generated at the grain boundaries in the non-FEZs. Moreover, based on theoretical calculation and result analysis, the activation energy was about 110.0 kJ/mol, and the hot tensile deformation mechanism was each other alternating and coordinated deformation mechanism among GBS, intragranular slip and dynamic recrystallization (DRX)
An improved method for grinding mill filling measurement and the estimation of load volume and mass
No full textThe fraction of mill volume occupied by rocks, grinding media and slurry in grinding mills are dominant factors influencing AG and SAG mill power draw and grinding rate. Hence accurate mill filling measurements are needed for modelling mills. To that end, it is usually necessary to enter the confined space of a grinding mill, a task that involves a degree of safety risk and a potentially lengthy plant stoppage. This paper discusses a range of available methods for measuring and calculating mill filling and introduces a new technique for accurately measuring filling that eliminates the need to enter the mill in most cases. The new method offers engineers and researchers a safer and faster method for quantifying the filling level in industrial SAG and ball mills, and allows the surface profile to be surveyed, without requiring the contents to be level. The paper also details formulas for calculating the filling level and load volume, which unlike previously published equations, also consider the volume in the conical ends and the volume occupied by the mill shell lifters
Gender differences and dose proportionality in the toxicokinetics of udenafil and its active metabolite following oral administration in rodents
No full textUdenafil is a long-acting oral phosphodiesterase type 5 inhibitor used to treat erectile dysfunction which may also have beneficial effects on cardiovascular diseases. Udenafil is mainly biotransformed to the active metabolite N-dealkylated udenafil via cytochrome P450 3A. The aim of this study was to investigate the gender differences and dose proportionality of the toxicokinetics of udenafil and its metabolite N-dealkylated udenafil in rodents. Udenafil was administered orally by gavage to male and female B6C3F1/N mice (100, 240, 350, and 500 mg/kg) and F344 rats (60, 120, and 240 mg/kg). Plasma concentrations of udenafil and N-dealkylated udenafil were simultaneous measured via liquid chromatography-tandem mass spectrometry. Female mice showed higher systemic exposure to udenafil than male mice, whereas female rats showed lower systemic exposure to udenafil than male rats after repeated administration at high dose. Systemic exposure to the metabolite, N-dealkylated udenafil, was lower in female than male mice and rats. A dose proportionality assessment by power model revealed a lack of dose proportionality in systemic exposure (C, AUC and AUC) after administration of 100–500 mg/kg of udenafil in mice and 60–240 mg/kg in rats. This study thus demonstrates gender and species differences with regard to the toxicokinetic profiles of udenafil and its active metabolite N-dealkylated udenafil after oral administration of udenafil to mice and rats of both sexes. Our findings suggest the possibility of gender differences in the toxicokinetics of udenafil in humans and suggests that further study is needed in this cohort
Divergence-based magnetic resonance electrical properties tomography
No full textMagnetic resonance electrical properties tomography (MR-EPT) maps the spatial distribution of the patient's electrical conductivity and permittivity using the measured\ua0B1\ua0\ua0data in a magnetic resonance imaging (MRI) system. Existing MR-EPT methods are usually not clinically accessible owing to their technical limits such as strong noise sensitivity. In this study, we develop a new MR-EPT method that re-expresses the involved differential equations (DEs) based on the divergence theorem. In comparison with traditional methods, the proposed method avoids the grid-wise computation of the second-order derivatives of\ua0\ua0B+1\ua0, thereby improving the robustness against noise. Besides, for applications where the structural information can be determined in advance, EPs of a region of interest (ROI) can be calculated in a fast and efficient manner. The proposed method is firstly validated with numerical simulations, in which a three-block phantom and an anatomically accurate Duke Head model are used to evaluate the proposed method. Experiments on the 9.4T MRI system were then conducted to validate the simulations. Both results indicated that the proposed MR-EPT solution could provide a more robust reconstruction of electrical properties maps compared with conventional methods
Aquatic environment remediation by atomic layer deposition-based multi-functional materials: A review
No full textWater pollution still poses significant threats to the ecosystem and human health today. The adsorption, advanced oxidation and membranes filtration have been extensively investigated and utilized for aquatic contaminants remediation, and their efficiency is closely correlated with the advanced materials design and fabrication (e.g. adsorbents, catalysts and membranes). Thanks to uniform deposition, three-dimensional conformity and process controllability, the atomic layer deposition (ALD) has emerged as a promising strategy for fabrication of these multifunctional materials, arising their successful application in aquatic contaminants remediation. Therefore, a timely review on ALD-based water treatment materials is highly important to summarize the current opportunity and elucidate unaddressed problems in this field. Herein, in this review, the advantages of ALD process, the superiority of ALD-based materials and the corresponding decontamination performance were analyzed comprehensively, highlighting key advantages offered by this technology
Control of Listeria monocytogenes on ready-to-eat ham and fresh cut iceberg lettuce using a nisin containing Lactococcus lactis fermentate
No full textListeria monocytogenes is a potentially deadly psychrotrophic pathogen that can cause illness through contamination of ready-to-eat (RTE) foods. In this work we evaluated the use of a fermentate consisting of cells and supernatant of a nisin producing Lactococcus lactis strain to control L. monocytogenes in foods. In addition, to determine the role of nisin production in this activity, a transposon screen was carried out to isolate a nisin-negative mutant. Several independent mutants containing transposon insertions in the nisin gene cluster were obtained which exhibited a complete loss of anti-L. monocytogenes activity in an agar-based assay. A simple media using food grade components was found to support strong growth and nisin production of Lc. lactis 537 following incubation at between 20 and 35 °C. The ability of the fermentate to control L. monocytogenes in foods was evaluated in cut iceberg lettuce and RTE sliced ham stored at 4 °C for 10 days. Initial levels of 10–10 CFU/g L. monocytogenes were reduced to below detection limit
Different effects of pectin and κ-carrageenan on the multiscale structures and in vitro digestibility of extruded rice starch
No full textThis study compared the different effects of pectin (PE) and κ-carrageenan (CG) on the multilevel structures (i.e. granule, crystallites, helices, fractals, and short-range order) and in vitro digestibility of extruded rice starch (MERS). The addition of either PE or CG altered the multiscale structures, increased the resistant component (RC) content, and reduced predicted glycemic index (pGI), with CG being more effective especially at a low content. CG led to the growth of molecular aggregates (α), single-helices, and V-type crystals (X). PE resulted in higher contents of double-helices and A + B-type crystals (X) and enhanced the short-range order (R) and particle compactness. Pearson correlation analysis indicates that, for MERS/PE, the slowly-digestible component (SDC) and RC contents were influenced by different factors in the sequence of total crystallinity (X) > X > X > single-helix content > α > R > double-helix content. For MERS/CG, the RC content was affected by X > single-helix content > X
Positive cognitive appraisal “buffers” the long-term effect of peritraumatic distress on maternal anxiety: the Queensland Flood Study
No full textBackground: Limited research has evaluated distinct aspects of disaster experience as predictors of affective symptoms. In this study, we examined the extent to which maternal depression and anxiety over time were predicted by (1) objective hardship from a flood during pregnancy, (2) peritraumatic distress and (3) cognitive appraisal of the flood's consequences. Methods: Data were drawn from the 2011 Queensland Flood Study, a prospective, longitudinal study of pregnancy (n = 183). Mothers’ disaster experience was measured within 1 year after the flood. Their levels of depression, anxiety and stress were measured at 16 months, 30 months, 4 years and 6 years after childbirth. Linear mixed models were employed to evaluate symptom trajectories. Results: There were no time-dependent effects of disaster-related variables. Objective hardship did not predict outcomes. Peritraumatic distress significantly predicted depression and anxiety symptoms when cognitive appraisal was negative. Conversely, when cognitive appraisal was neutral or positive, the effect of peritraumatic distress was “buffered”. For anxiety, but not depression, this interaction survived Bonferroni correction. Neutral/ positive cognitive appraisal similarly moderated the effect of peritraumatic dissociation. Limitations: The generalizability of our findings is limited by overall low levels of depression and anxiety, along with a predominantly Caucasian, higher socioeconomic status sample. Potential confounders such as pre-disaster anxiety were not controlled for. Conclusion: In line with previous evidence, this study supports the predictive validity of peritraumatic distress for post-disaster depression and anxiety. Our findings suggest that cognitive appraisal could be a relevant target for interventions aimed at fostering maternal resilience
Mechanisms of mercury with typical organics in the incineration of sewage sludge: A computational investigation
No full textIn this work, using quantum chemistry methods the reactions of Hg and HgO with six organics including methane (CH), benzene (CH), methanol (CHOH), formaldehyde (HCHO), formic acid (HCOOH) and phenol (CHOH) in sludge incineration were investigated. The computational result indicates that Hg reacts with six organics via insertion mechanism to form CHHgH, CHOHgH, CHHgOH, HHgCHOH, HCOHgH, HCHgO, HHgCOOH, HOCHHgO, HCOOHgH, HCOHgOH, CHHgH, CHOHgH, CHHgOH, and m-, o-, p-HHgCHOH. However, all barriers involved are extremely high and all products are rather unstable, therefore, Hg will be discharged as elements into fuel gas. With extra oxygen supplied Hg could be oxidized to HgO firstly; subsequently, CHOHgOH, HCOHgOH, HOCOHgOH, CHHgOH and o-HOHgCH-OH were formed when HgO reacts with above above organics. The corresponding barriers are lower and all products are much more stable, indicating these Hg-contained organic compounds would be generated readily in incineration of sludge. Therefore it is presumed that in presence of oxygen Hg is more active to react with organics in sludge incineration
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