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Iodine intake and excretion vary widely; however, these variations remain a large source of geometric uncertainty. The present study aims to analyse variations in iodine intake and excretion and provide implications for sampling in studies of individuals or populations. Twenty-four healthy women volunteers were recruited for a 12-d sampling period during the 4-week experiment. The duplicate-portion technique was used to measure iodine intake, while 24-h urine was collected to estimate iodine excretion. The mean intra-individual variations in iodine intake, 24-h UIE (24-h urinary iodine excretion) and 24-h UIC (24-h urinary iodine concentration) were 63, 48 and 55 %, respectively, while the inter-individual variations for these parameters were 14, 24 and 32 %, respectively. For 95 % confidence, approximately 500 diet samples or 24-h urine samples should be taken from an individual to estimate their iodine intake or iodine status at a precision range of ±5%. Obtaining a precision range of ±5% in a population would require twenty-five diet samples or 150 24-h urine samples. The intra-individual variations in iodine intake and excretion were higher than the inter-individual variations, which indicates the need for more samples in a study on individual participants.
The present study aimed to investigate whether dietary choline can regulate lipid metabolism and suppress NFκB activation and, consequently, attenuate inflammation induced by a high-fat diet in black sea bream (Acanthopagrus schlegelii). An 8-week feeding trial was conducted on fish with an initial weight of 8·16 ± 0·01 g. Five diets were formulated: control, low-fat diet (11 %); HFD, high-fat diet (17 %); and HFD supplemented with graded levels of choline (3, 6 or 12 g/kg) termed HFD + C1, HFD + C2 and HFD + C3, respectively. Dietary choline decreased lipid content in whole body and tissues. Highest TAG and cholesterol concentrations in serum and liver were recorded in fish fed the HFD. Similarly, compared with fish fed the HFD, dietary choline reduced vacuolar fat drops and ameliorated HFD-induced pathological changes in liver. Expression of genes of lipolysis pathways were up-regulated, and genes of lipogenesis down-regulated, by dietary choline compared with fish fed the HFD. Expression of nfκb and pro-inflammatory cytokines in liver and intestine was suppressed by choline supplementation, whereas expression of anti-inflammatory cytokines was promoted in fish fed choline-supplemented diets. In fish that received lipopolysaccharide to stimulate inflammatory responses, the expression of nfκb and pro-inflammatory cytokines in liver, intestine and kidney were all down-regulated by dietary choline compared with the HFD. Overall, the present study indicated that dietary choline had a lipid-lowering effect, which could protect the liver by regulating intrahepatic lipid metabolism, reducing lipid droplet accumulation and suppressing NFκB activation, consequently attenuating HFD-induced inflammation in A. schlegelii.
For decades, fructose intake has been recognised as an environmental risk for metabolic syndromes and diseases. Here we comprehensively examined the effects of fructose intake on mice liver transcriptomes. Fructose-supplemented water (34 %; w/v) was fed to both male and female C57BL/6N mice at their free will for 6 weeks, followed by hepatic transcriptomics analysis. Based on our criteria, differentially expressed genes (DEG) were selected and subjected to further computational analyses to predict key pathways and upstream regulator(s). Subsequently, predicted genes and pathways from the transcriptomics dataset were validated via quantitative RT-PCR analyses. As a result, we identified eighty-nine down-regulated and eighty-eight up-regulated mRNA in fructose-fed mice livers. These DEG were subjected to bioinformatics analysis tools in which DEG were mainly enriched in xenobiotic metabolic processes; further, in the Ingenuity Pathway Analysis software, it was suggested that the aryl hydrocarbon receptor (AhR) is an upstream regulator governing overall changes, while fructose suppresses the AhR signalling pathway. In our quantitative RT-PCR validation, we confirmed that fructose suppressed AhR signalling through modulating expressions of transcription factor (AhR nuclear translocator; Arnt) and upstream regulators (Ncor2, and Rb1). Altogether, we demonstrated that ad libitum fructose intake suppresses the canonical AhR signalling pathway in C57BL/6N mice liver. Based on our current observations, further studies are warranted, especially with regard to the effects of co-exposure to fructose on (1) other types of carcinogens and (2) inflammation-inducing agents (or even diets such as a high-fat diet), to find implications of fructose-induced AhR suppression.
Associations between ferritin and insulin sensitivity have been described in recent studies. The possible association showed conflicting results by sex and menopausal status. We aimed to investigate the cross-sectional association of ferritin levels with insulin resistance and β-cell function. A total of 2518 participants (1033 men, 235 pre-menopausal women and 1250 post-menopausal women) were enrolled from the Changfeng Study. A standard interview was conducted, as well as anthropometric measurements and laboratory analyses, for each participant. The serum ferritin level was measured using electrochemiluminescence immunoassay. Insulin resistance and β-cell function indices were derived from a homeostasis model assessment. The results showed that the serum ferritin levels were 250·4 (sd 165·2), 94·6 (sd 82·0) and 179·8 (sd 126·6) ng/ml in the men, pre-menopausal and post-menopausal women, respectively. In fully adjusted models (adjusting for age, current smoking, BMI, waist:hip ratio, systolic blood pressure, diastolic blood pressure, TAG, HDL-cholesterol, LDL-cholesterol, log urine albumin:creatinine ratio, leucocytes, alanine aminotransferase, aspartate aminotransferase and γ-glutamyl transpeptidase), serum ferritin concentrations are significantly associated with insulin resistance in men and post-menopausal females, and the null association was observed in pre-menopausal females. Interestingly, an increased β-cell function associated with higher ferritin was observed in post-menopausal participants, but not in male participants. In conclusion, these results suggested that elevated serum ferritin levels were associated with surrogate measures of insulin resistance among the middle-aged and elderly male and post-menopausal women, but not in pre-menopausal women.
The prevalence of impaired fasting glucose (IFG) and diabetes mellitus (DM) has reportedly increased significantly among Chinese children and adolescents. We aimed to examine the prevalence of IFG and DM, the disparities in sex and region and related risk factors among Chinese children and adolescents. A total of 16 434 Chinese children aged 6–17 years were selected from a national cross-sectional survey, and fasting glucose was measured for all participants. Overall, mean fasting plasma glucose (FPG) concentration was (4·64 (sd 0·51)) mmol/l, and the prevalence of DM and IFG was 0·10 and 1·89 %, respectively. Compared with girls, boys had higher FPG concentration (4·69 v. 4·58 mmol/l, r 0·107, P<0·001) and IFG prevalence (2·67 v. 1·07 %, rφ 0·059, P<0·001). Compared with rural children and adolescents, urban children and adolescent had higher FPG concentration (4·65 v. 4·62 mmol/l, r 0·029, P<0·001) and DM prevalence (0·15 v. 0·05 %, rφ 0·016, P<0·01). In addition, self-reported fried foods intake and overweight/obesity were positively associated with IFG, and the proportion of consuming fried foods more than or equal to once per week and overweight/obesity prevalence in boys and urban children and adolescents were significantly higher than girls and rural children and adolescents, respectively (P<0·05). Although the prevalence of IFG and DM was relatively low in Chinese children and adolescents, sex and region disparities were observed, which may be associated with differences in overweight/obesity prevalence and dietary factors.
A series of Ba-modified MnCeOx/TiO2 catalysts were prepared by a wet impregnation method and tested for selective catalytic reduction (SCR) of NO with NH3 at low temperature. The results showed that Ba additives obviously improved the catalytic performance of the MnCeOx/TiO2 catalyst for NH3-SCR, and the BaMnCeOx/TiO2 catalyst with 3 wt% BaO exhibited the optimal catalytic performance. Moreover, the introduction of Ba also improved the resistances toward water vapor and SO2 of catalysts. The N2 adsorption, H2-TPR, and X-ray photoelectron spectroscopy results showed that the addition of Ba increased the specific surface area, redox properties, and concentrations of surface Mn4+ and chemisorbed oxygen of catalysts. Furthermore, NH3-TPD and NO-TPD were used to investigate the absorption of NH3 and NO on the catalyst. The results revealed that although the introduction of Ba significantly promoted the adsorption of NO, it also inhibited the adsorption of NH3. Consequently, the catalytic performance of MnCeOx/TiO2 was greatly improved with the Ba additives.
The dynamics of vortical structures in flow over a circular cylinder in the vicinity of a flat plate is investigated using particle image velocimetry (PIV). The cylinder is placed above the flat plate with its axis parallel to the wall and normal to the flow direction. The Reynolds number
based on the cylinder diameter
is 1072 and the gap
between the cylinder and the flat plate is varied from gap-to-diameter ratio
. The flow statistics and vortex dynamics are strongly dependent on the gap ratio
. Statistics show that as the cylinder comes close to the wall (
), the cylinder wake becomes more and more asymmetric and a boundary layer separation is induced on the flat plate downstream of the cylinder. The wake vortex shedding frequency increases with decreasing
until a critical gap ratio (about
) below which the vortex shedding is irregular. The deflection of the gap flow away from the wall and its following interaction with the upper shear layer may be the cause of the higher shedding frequency. The vortex dynamics is investigated based on the phase-averaged flow field and virtual dye visualization in the instantaneous PIV velocity field. It is revealed that when the cylinder is close to the wall (
), the cylinder wake vortices can periodically induce secondary spanwise vortices near the wall. As the cylinder approaches the wall (
) the secondary vortex can directly interact with the lower wake vortex, and a further approaching of the cylinder (
) can result in more complex interactions among the secondary vortex, the lower wake vortex and the upper wake vortex. The breakdown of vortices into filamentary debris during vortex interactions is clearly revealed by the coloured virtual dye visualizations. For
, the lower shear layer is strongly inhibited and only the upper shear layer can shed vortices. Investigation of the vortex formation, evolution and interaction in the flow promotes the understanding of the flow physics for different gap ratios.
The high-energy oscillating electric current pulse (ECP) technology was introduced to relieve the residual stresses in the small AISI 1045 steel specimens treated by the pulsed-laser surface irradiation. The high-energy oscillating ECP stress relief experiments were conducted to study the effectiveness of the high-energy oscillating ECP technology. In addition, the electroplasticity framework was developed based on the thermal activation theory to reveal the mechanism of the high-energy oscillating ECP stress relief. The results show that the high-energy oscillating ECP stress relief has good effects on eliminating the residual stress. Furthermore, the residual stress relieving mechanism of the high-energy oscillating ECP stress relief can be attributed to the electric softening effect and the dynamic stress effect. The findings confirm that the significant effects of high-energy oscillating ECP on metal plasticity and provide a basis to understand the underlying mechanism of the high-energy oscillating ECP stress relief.
The high-frequency vibration technology was introduced to relieve the quenched residual stress in the Cr12MoV steel based on the high-frequency vibration system that mainly consisted of an electromagnetic vibrator and an amplitude boost unit. The high-frequency vibratory stress relief (VSR) experiments were conducted to study the effectiveness of the high-frequency vibration technology. In addition, the high-frequency vibration plasticity model was developed based on the thermal activation theory to reveal the mechanism of the high-frequency VSR. The results show that the high-frequency VSR has good effects on eliminating residual stress, while the surface hardness for the Cr12MoV steel remains almost the same. Moreover, there are no changes in the grain size of the Cr12MoV steel during the high-frequency VSR, while the dislocation density for the Cr12MoV steel during the high-frequency VSR decreases by 27.21%. The decrease of dislocation density in the Cr12MoV steel is the essence of residual stress relaxation. The findings confirm the significant effects of high-frequency vibration on metal plasticity and provide a basis to understand the underlying mechanism of the high-frequency VSR.
The metamorphic responses of mussel (Mytilus coruscus) larvae to pharmacological agents affecting G proteins and the adenylate cyclase/cyclic AMP (AC/cAMP) pathway were examined in the laboratory. The G protein activators guanosine 5′-[β,γ-imido]triphosphate trisodium salt hydrate and guanosine 5′-[γ-thio]triphosphate tetralithium salt only induced larval metamorphosis in continuous exposure assays, and the G protein inhibitor guanosine 5′-[β-thio]diphosphate trilithium salt did not exhibit inducing activity. The non-specific phosphodiesterase inhibitor theophylline and the cAMP-specific phosphodiesterase IV inhibitor 4-(3-Butoxy-4-methoxybenzyl)imidazolidin-2-one exhibited inducing activity, while the non-specific phosphodiesterase inhibitor 3-Isobutyl-1-methylxanthine only showed inducing activity at 10−4 M in continuous exposure assays. The cyclic nucleotide analogue N6,2′-O-Dibutyryladenosine 3′,5′-cyclic monophosphate sodium salt did not exhibit significant inducing activity. Both the adenylate cyclase activator forskolin and the adenylate cyclase inhibitor nitroimidazole exhibited inducing activity at 10−4 to 10−3 M concentrations in continuous exposure assays. Among these tested agents, the adenylate cyclase inhibitor (±)-miconazole nitrate salt showed the most promising inducing effect. The present results indicate that G protein-coupled receptors and signal transduction by AC/cAMP pathway could mediate metamorphosis of larvae in this species.
A multi-region scene matching-based localisation system for automated navigation of Unmanned Aerial Vehicles (UAV) is proposed. This system may serve as a backup navigation error correction system to support autonomous navigation in the absence of a global positioning system such as a Global Navigation Satellite System. Conceptually, the system computes the location of the UAV by comparing the sensed images taken by an on board optical camera with a library of pre-recorded geo-referenced images. Several challenging issues in building such a system are addressed, including the colour variability problem and elimination of time-varying details from the pairs of images. The overall algorithm is an iterative process involving four sub-processes: firstly, exact histogram matching is applied to sensed images to overcome the colour variability issues; secondly, regions are automatically extracted from the sensed image where landmarks are detected via their colour histograms; thirdly, these regions are matched against the library, while eliminating inconsistent regions between underlying image pairs in the registration process; and finally the location of the UAV is computed using an optimisation procedure which minimises the localisation error using affine transformations. Experimental results demonstrate the proposed system in terms of accuracy, robustness and computational efficiency.
Evolution of Lagrangian coherent structures (LCS) in a flat plate boundary layer transition induced by the wake of a circular cylinder is investigated. Both hydrogen bubble visualization and particle image velocimetry (PIV) techniques are used. It is found that downstream of the cylinder, the disturbance in the boundary layer experiences a fast growth followed by a slow decay in the transition. Lagrangian coherent structures are revealed by qualitative hydrogen bubble visualizations and quantitative finite-time Lyapunov exponents (FTLE) fields derived from the PIV data. The evolution of the LCS is considered from the very beginning of the transition up to when the boundary layer becomes fully developed turbulent flow. The mean convection velocity and average inclination angle of the LCS are first extracted from the FTLE fields. The streamwise length of the low-speed streaks seems to increase, while their spanwise distance decreases in the boundary layer transition. Proper orthogonal decomposition (POD) of the PIV data shows that low-speed streaks associated with the hairpin vortices and hairpin packets are the dominant coherent structures close to the wall in the transitional and turbulent boundary layer. The POD modes also reveal a variety of scales in the turbulent boundary layer. Moreover, it is found that large-scale coherent structures can modulate the amplitude of the small-scale ones.
Mussels are typical macrofouling organisms in the world. In this study, the interaction between the settlement of Mytilus coruscus plantigrades and bacterial community on coloured substrata was determined. Bacterial communities in biofilms developed on seven coloured substrata were analysed by Illumina Miseq sequencing. The mussel settlement response to coloured substrata with no biofilms was also examined. Flavobacteria, Alphaproteobacteria and Gammaproteobacteria were the first, second and third most dominant groups in seven biofilm samples. The results suggest that the inducing activities of these biofilms on plantigrade settlement varied with coloured substrata and the lowest percentage of settlement was observed on biofilms on the green substratum. High-throughput sequencing showed that bacterial community in biofilms also changed with the substratum colour. No significant difference in the inducing activity on plantigrade settlement was observed between the coloured substrata with no biofilms. Thus, difference in plantigrade settlement response may be correlated to the changes in bacterial community on coloured substrata. This finding extends current knowledge of interaction among mussel settlement and bacterial community variability.
Postmenopausal women are at increased risk of CVD: the increased serum ferritin level may be involved in the pathogenesis. The aim of the present study is to investigate the relationship of ferritin and carotid atherosclerosis in postmenopausal women. A total of 1178 postmenopausal women (mean age, 60·8 years) were enrolled from the Changfeng Study. A standard interview, anthropometric measurements and laboratory analyses were performed for each participant. Bilateral CIMT (carotid intima–media thickness) were measured using ultrasonography, and the presence of carotid plaques was assessed. Serum ferritin was measured using electrochemiluminescence immunoassay. The results showed that serum ferritin was 181·9 (sd 65·8) ng/ml in the postmenopausal women. Multivariate, linear, stepwise regression analysis demonstrated that age (standardised β = 0·233, P< 0·001), alanine transaminase (standardised β = 0·194, P< 0·001), log homeostasis model assessment index for insulin resistance (standardised β = 0·181, P< 0·001), TAG (standardised β = 0·083, P= 0·003), Hb (standardised β = 0·080, P= 0·004) and PPG (2-h glucose levels following a 75-g oral glucose challenge) (standardised β = 0·079, P= 0·004) were independently associated with serum ferritin. Compared with the ferritin level of subjects in the first quartile, that in the fourth quartile had greater CIMT, and higher prevalence of carotid plaque. After adjusting for conventional CVD risk factors, Hb, leucocytes, log urine albumin:creatinine ratio and liver function, the ferritin level of postmenopausal women in the fourth quartile had a 1·587-fold increased risk of carotid plaques relative to those in the lowest quartile. In conclusion, these results suggest that serum ferritin is independently and positively associated with carotid atherosclerosis in postmenopausal women and that ferritin may be implicated in atherosclerosis.
Few studies have explored the relationship between dietary patterns and the risk of gestational diabetes mellitus (GDM). Evidence from non-Western areas is particularly lacking. In the present study, we aimed to examine the associations between dietary patterns and the risk of GDM in a Chinese population. A total of 3063 pregnant Chinese women from an ongoing prospective cohort study were included. Data on dietary intake were collected using a FFQ at 24–27 weeks of gestation. GDM was diagnosed using a 75 g, 2 h oral glucose tolerance test. Dietary patterns were determined by principal components factor analysis. A log-binomial regression model was used to examine the associations between dietary pattern and the risk of GDM. The analysis identified four dietary patterns: vegetable pattern; protein-rich pattern; prudent pattern; sweets and seafood pattern. Multivariate analysis showed that the highest tertile of the vegetable pattern was associated with a decreased risk of GDM (relative risk (RR) 0·79, 95 % CI 0·64, 0·97), compared with the lowest tertile, whereas the highest tertile of the sweets and seafood pattern was associated with an increased risk of GDM (RR 1·23, 95 % CI 1·02, 1·49). No significant association was found for either the protein-rich or the prudent pattern. The protective effect of a high vegetable pattern score was more evident among women who had a family history of diabetes (P for interaction = 0·022). These findings suggest that the vegetable pattern was associated with a decreased risk of GDM, while the sweets and seafood pattern was associated with an increased risk of GDM. These findings may be useful in dietary counselling during pregnancy.
The enteric pathogens causing diarrhoea impair children's health severely. This study retrospectively analysed 1577 pathogens isolated from inpatients and outpatients in six hospitals located in Northern (Inner Mongolia), Northeastern (Hebei), Eastern (Shanghai and Jiangsu), Southern (Hainan) and Central (Hubei) China between 2008 and 2013. Of the 1577 enteric pathogens, Salmonella presented with the highest frequency (36·0%), followed by diarrhoeagenic Escherichia coli (23·7%), Staphylococcus aureus (15·0%), Shigella (13·1%), and Aeromonas (4·6%). The predominant pathogens varied in different regions of China, with Salmonella most prevalent in Shanghai and Hainan, diarrhoeagenic E. coli most prevalent in Inner Mongolia, Jiangsu and Hubei, and Shigella most prevalent in Hebei. Enteric pathogens were more frequently isolated in males (56·9%) than in females (43·1%). The highest proportion of all enteric pathogens was found in infants (67·6%) with a peak in summer and autumn (68·5%). Antimicrobial susceptibility assay demonstrated that Shigella was more resistant to ampicillin, ceftriaxone and sulfamethoxazole than Salmonella. Of the top two serotypes in Salmonella, Typhimurium was more resistant to ciprofloxacin, sulfamethoxazole and chloramphenicol than Enteritidis (P < 0·001). Meanwhile, the resistance rates of Shigella flexneri against ampicillin/sulbactam, ciprofloxacin, and chloramphenicol were significantly higher than those of Shigella sonnei (P < 0·001). Multidrug resistance was apparent in 58·2% of Shigella and 45·9% of Salmonella, and this phenomenon was more pronounced in S. flexneri.
Surface properties affect the attachment of micro- and macroscopic marine organisms. The current study examined the settlement response of the mussel Mytilus coruscus plantigrades to natural biofilms formed on surfaces of different wettability. The percentages of plantigrade settlement were not influenced by the biofilms formed on variously wettable surfaces in the short term, but after 10 days, the plantigrade settlement rates decreased on biofilms formed on lower wettability surfaces. In general, lower wettability of the surfaces resulted in the decrease of the dry weight, bacterial and diatom density and the thickness of natural biofilms when compared to high wettability surfaces. In contrast, chlorophyll-a concentration in biofilms was independent of the initial wettability of the surfaces. Comparative cluster analysis of bacterial denaturing gradient gel electrophoresis patterns revealed that high variability existed between the bacterial community on high wettability surfaces and that on low wettability surfaces. Thus, surface wettability affects the formation of natural biofilms, and this variation in biofilms developed on different wettability surfaces may explain the discrepancy in their corresponding inducing activities on M. coruscus plantigrade settlement. This finding provides new insight into interactions between mussel settlement, biofilm characteristics and surface properties.