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There is still controversy about optimal dietary iodine intake as the Universal Salt Iodization policy enforcement in China. A modified iodine balance study was thus conducted to explore the suitable iodine intake in Chinese adult males using the iodine overflow hypothesis. In this study, thirty-eight apparently healthy males (19·1 (sd 0·6) years) were recruited and provided with designed diets. After the 14-d iodine depletion, daily iodine intake gradually increased in the 30-d iodine supplementation, consisting of six stages and each of 5 d. All foods and excreta (urine, faeces) were collected to examine daily iodine intake, iodine excretion and the changes of iodine increment in relation to those values at stage 1. The dose–response associations of iodine intake increment with excretion increment were fitted by the mixed effects models, as well as with retention increment. Daily iodine intake and excretion were 16·3 and 54·3 μg/d at stage 1, and iodine intake increment increased from 11·2 μg/d at stage 2 to 118·0 μg/d at stage 6, while excretion increment elevated from 21·5 to 95·0 μg/d. A zero iodine balance was dynamically achieved as 48·0 μg/d of iodine intake. The estimated average requirement and recommended nutrient intake were severally 48·0 and 67·2 μg/d, which could be corresponded to a daily iodine intake of 0·74 and 1·04 μg/kg per d. The results of our study indicate that roughly half of current iodine intakes recommendation could be enough in Chinese adult males, which would be beneficial for the revision of dietary reference intakes.
Data on average iodine requirements for the Chinese population are limited following implementation of long-term universal salt iodisation. We explored the minimum iodine requirements of young adults in China using a balance experiment and the ‘iodine overflow’ hypothesis proposed by our team. Sixty healthy young adults were enrolled to consume a sequential experimental diet containing low, medium and high levels of iodine (about 20, 40 and 60 μg/d, respectively). Each dose was consumed for 4 d, and daily iodine intake, excretion and retention were assessed. All participants were in negative iodine balance throughout the study. Iodine intake, excretion and retention differed among the three iodine levels (P < 0·01 for all groups). The zero-iodine balance derived from a random effect model indicated a mean iodine intake of 102 μg/d, but poor correlation coefficients between observed and predicted iodine excretion (r 0·538 for μg/d data) and retention (r 0·304 for μg/d data). As iodine intake increased from medium to high, all of the increased iodine was excreted (‘overflow’) through urine and faeces by males, and 89·5 % was excreted by females. Although the high iodine level (63·4 μg/d) might be adequate in males, the corresponding level of 61·6 μg/d in females did not meet optimal requirements. Our findings indicate that a daily iodine intake of approximately half the current recommended nutrient intake (120 μg/d) may satisfy the minimum iodine requirements of young male adults in China, while a similar level is insufficient for females based on the ‘iodine overflow’ hypothesis.
Ketosis is a metabolic disease of dairy cows often characterized by high concentrations of ketone bodies and fatty acids, but low milk protein and milk production. The Janus kinase 2 (JAK2)-signal transducer and activator of transcription 5 (STAT5) and the mechanistic target of rapamycin (mTOR) signaling pathways are central for the regulation of milk protein synthesis. The effect of high levels of fatty acids on these pathways and β-casein synthesis are unknown in dairy cows with clinical ketosis. Mammary gland tissue and blood samples were collected from healthy (n = 15) and clinically-ketotic (n = 15) cows. In addition, bovine mammary epithelial cells (BMEC) were treated with fatty acids, methionine (Met) or prolactin (PRL), respectively. In vivo, the serum concentration of fatty acids was greater (P > 0.05) and the percentage of milk protein (P > 0.05) was lower in cows with clinical ketosis. The JAK2-STAT5 and mTOR signaling pathways were inhibited and the abundance of β-casein was lower in mammary tissue of cows with clinical ketosis (P > 0.05). In vitro, high levels of fatty acids inhibited the JAK2-STAT5 and mTOR signaling pathways (P > 0.05) and further decreased the β-casein synthesis (P > 0.05) in BMEC. Methionine or PRL treatment, as positive regulators, activated the JAK2-STAT5 and mTOR signaling pathways to increase the β-casein synthesis. Importantly, the high concentration of fatty acids attenuated the positive effect of Met or PRL on mTOR, JAK2-STAT5 pathways and the abundance of β-casein (P > 0.05). Overall, these data indicate that the high concentrations of fatty acids that reach the mammary cells during clinical ketosis inhibit mTOR and JAK2-STAT5 signaling pathways, and further suppress β-casein synthesis.
Underground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors were commissioned. JUNA plans to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. At the first period, JUNA aims at the direct measurements of 25Mg(p,γ)26 Al, 19F(p,α) 16 O, 13C(α, n) 16O and 12C(α,γ) 16O near the Gamow window. The current progress of JUNA will be given.
Dairy cows with ketosis display severe oxidative stress as well as high blood concentrations of non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB). Cytochrome P4502E1 (CYP2E1) plays an important role in the induction of oxidative stress. The aim of this study was to investigate CYP2E1 expression and activity in the liver of clinically ketotic cows (in vivo) and the effects of NEFA and BHB on CYP2E1 expression and activity in hepatocytes (in vitro). Dairy cows with clinical ketosis exhibited a low blood concentration of glucose but high concentrations of NEFA and BHB. Hepatic mRNA, protein expression, and activity of CYP2E1 were significantly higher in cows with clinical ketosis than in control cows. In vitro, both NEFA and BHB treatment markedly up-regulated the mRNA and protein expressions as well as activity of CYP2E1 in cow hepatocytes. Taken together, these results indicate that high levels of NEFA and BHB significantly up-regulate the expression and activity of hepatic CYP2E1, and may be influential in the induction of oxidative stress in cows with clinical ketosis.
We hypothesize that the tumor necrosis factor-α (TNF-α) may play a role in disturbing the effect of selective serotonin reuptake inhibitor (SSRI) on the striatal connectivity in patients with major depressive disorder (MDD).
We performed a longitudinal observation by combining resting-state functional magnetic resonance imaging (rs-fMRI) and biochemical analyses to identify the abnormal striatal connectivity in MDD patients, and to evaluate the effect of TNF-α level on these abnormal connectivities during SSRI treatment. Eighty-five rs-fMRI scans were collected from 25 MDD patients and 35 healthy controls, and the scans were repeated for all the patients before and after a 6-week SSRI treatment. Whole-brain voxel-wise functional connectivity (FC) was calculated by correlating the rs-fMRI time courses between each voxel and the striatal seeds (i.e. spherical regions placed at the striatums). The level of TNF-α in serum was evaluated by Milliplex assay. Factorial analysis was performed to assess the interaction effects of ‘TNF-α × treatment’ in the regions with between-group FC difference.
Compared with controls, MDD patients showed significantly higher striatal FC in the medial prefrontal cortex (MPFC) and bilateral middle/superior temporal cortices before SSRI treatment (p < 0.001, uncorrected). Moreover, a significant interaction effect of ‘TNF-α × treatment’ was found in MPFC-striatum FC in MDD patients (p = 0.002), and the significance remained after adjusted for age, gender, head motion, and episode of disease.
These findings provide evidence that treatment-related brain connectivity change is dependent on the TNF-α level in MDD patients, and the MPFC-striatum connectivities possibly serve as an important target in the brain.
Dairy cows with type II ketosis display hepatic fat accumulation and hyperinsulinemia, but the underlying mechanism is not completely clear. This study aimed to clarify the regulation of lipid metabolism by insulin in cow hepatocytes. In vitro, cow hepatocytes were treated with 0, 1, 10, or 100 nm insulin in the presence or absence of AICAR (an AMP-activated protein kinase alpha (AMPKα) activator). The results showed that insulin decreased AMPKα phosphorylation. This inactivation of AMPKα increased the gene and protein expression levels of carbohydrate responsive element-binding protein (ChREBP) and sterol regulatory element-binding protein-1c (SREBP-1c), which downregulated the expression of lipogenic genes, thereby decreasing lipid biosynthesis. Furthermore, AMPKα inactivation decreased the gene and protein expression levels of peroxisome proliferator-activated receptor-α (PPARα), which upregulated the expression of lipid oxidation genes, thereby increasing lipid oxidation. In addition, insulin decreased the very low density lipoprotein (VLDL) assembly. Consequently, triglyceride content was significantly increased in insulin treated hepatocytes. Activation of AMPKα induced by AICAR could reverse the effect of insulin on PPARα, SREBP-1c, and ChREBP, thereby decreasing triglyceride content. These results indicate that insulin inhibits the AMPKα signaling pathway to increase lipid synthesis and decrease lipid oxidation and VLDL assembly in cow hepatocytes, thereby inducing TG accumulation. This mechanism could partly explain the causal relationship between hepatic fat accumulation and hyperinsulinemia in dairy cows with type II ketosis.
Dairy cows with fatty liver or ketosis exhibit hyperketonemia, oxidative stress, and a low rate of very low density lipoprotein (VLDL) assembly, and there may be a potential link among these characteristics. Therefore, the objective of this study was to determine the effect of acetoacetic acid (AcAc) on the assembly of VLDL in cow hepatocytes. Cultured cow hepatocytes were treated with different concentrations of AcAc with or without N-acetylcysteine (NAC, an antioxidant). AcAc treatment decreased the mRNA expression and activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), and significantly increased malondialdehyde (MDA) content, indicative of oxidative stress. Furthermore, AcAc treatment significantly down-regulated the mRNA expression of apolipoprotein B100 (ApoB100), apolipoprotein E (ApoE), and low density lipoprotein receptor (LDLR), which thus decreased VLDL assembly and increased triglyceride (TG) accumulation in these bovine hepatocytes. Importantly, NAC relieved AcAc-induced oxidative stress and increased VLDL assembly. In summary, these results suggest that AcAc-induced oxidative stress affects the assembly of VLDL, which increases TG accumulation in bovine hepatocytes.
Elevated levels of blood interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumour necrosis factor–α (TNF–α) increase insulin resistance and result in inflammation. It is not clear whether elevated blood level of acetoacetate (ACAC) and decreased blood level of glucose, which are the predominant characteristics of clinical biochemistry in ketotic dairy cows, increase proinflammatory cytokines and subsequent inflammation. The objective of this study was to test the hypothesis that ACAC and glucose activate the NF-κB signalling pathway to regulate cytokines expression in bovine hepatocytes. Bovine hepatocytes were cultured with ACAC (0–4·8 mm) and glucose (0–5·55 mm) with or without NF-κB inhibitor PDTC for 24 h. The secretion and mRNA levels of cytokines were determined by enzyme-linked immunosorbent assay (ELISA) and real-time fluorescence quantitative polymerase chain reaction (qRT-PCR). The NF-κB signalling pathway activation was evaluated by western blotting. Results showed that the secretion and expression of IL-1β, IL-6 and TNF-α increased in an ACAC dose-dependent manner. Additionally, there was an increase in the secretion and mRNA expression of these three cytokines in glucose treatment group, which increased significantly when the glucose concentrations exceed 3·33 mm. Furthermore, both ACAC and glucose upregulated NF-κB p65 protein expression and IκBα phosphorylation levels. However, these effects were reduced by PDTC. These results demonstrate that elevated levels of ACAC and glucose increase the synthesis and expression of proinflammatory factors by activating NF-κB signalling pathway in hepatocytes, which may contribute to inflammation injury in ketotic dairy cows.
We thank Anning Hu for carefully reading and commenting on our report “College is a rich, Han, urban, male club: research notes from a census survey of four tier one colleges in China.” We also thank the editor of The China Quarterly for giving us the chance to respond to the commentary. The topic of assessing disparities in college access in China (and other developing countries undergoing major transitions in their higher education systems) is an important one. We hope that our China Quarterly article, Hu's commentary and our response will stimulate more research and dialogue on this topic in China and elsewhere.
The opportunity to attend college and earn a degree has increased dramatically in China. However, that does not mean that everyone has an equal opportunity. Historically, there has been well-documented systematic discrimination against minorities, women and the rural poor. The main question of this paper is whether or not this discrimination has persisted since the recent expansion of China's tertiary education system. Using a census of incoming freshmen from four tier one universities, this paper assesses if certain types of students are over-represented while other types of students are under-represented. Comparing the shares of students from different socioeconomic and ethnic backgrounds from our primary survey data with government generated census statistics, we conclude that poor, minority and rural female students are systematically under-represented. In contrast, rich, Han, urban males are dominant in college.
We made an amorphous-silicon (a-Si) solar cell with a nanowire-array structure on stainless steel(SS) by plasma enhanced chemical vapor (PECVD) deposition. This nanowire structure has an n-type Si nanowire array in which a-Si intrinsic layer and p type layer are sequentially grown on the surface of the nanowire. The highest open-circuit voltage (Voc) and short-circuit current density (Jsc) for AM 1.5 illumination were 620 mV and 13.4 mA/cm2, respectively at a maximum power conversion efficiency of 3.57%.
Lignans, derived from flaxseed, are phyto-oestrogens being increasingly studied for their health benefits. An 8-week, randomised, double-blind, placebo-controlled study was conducted in fifty-five hypercholesterolaemic subjects, using treatments of 0 (placebo), 300 or 600 mg/d of dietary secoisolariciresinol diglucoside (SDG) from flaxseed extract to determine the effect on plasma lipids and fasting glucose levels. Significant treatment effects were achieved (P < 0·05 to < 0·001) for the decrease of total cholesterol (TC), LDL-cholesterol (LDL-C) and glucose concentrations, as well as their percentage decrease from baseline. At weeks 6 and 8 in the 600 mg SDG group, the decreases of TC and LDL-C concentrations were in the range from 22·0 to 24·38 % respectively (all P < 0·005 compared with placebo). For the 300 mg SDG group, only significant differences from baseline were observed for decreases of TC and LDL-C. A substantial effect on lowering concentrations of fasting plasma glucose was also noted in the 600 mg SDG group at weeks 6 and 8, especially in the subjects with baseline glucose concentrations ≥ 5·83 mmol/l (lowered 25·56 and 24·96 %; P = 0·015 and P = 0·012 compared with placebo, respectively). Plasma concentrations of secoisolariciresinol (SECO), enterodiol (ED) and enterolactone were all significantly raised in the groups supplemented with flaxseed lignan. The observed cholesterol-lowering values were correlated with the concentrations of plasma SECO and ED (r 0·128–0·302; P < 0·05 to < 0·001). In conclusion, dietary flaxseed lignan extract decreased plasma cholesterol and glucose concentrations in a dose-dependent manner.
A ∼500 kV/400 kA/100 ns pulsed power generator (PPG-I) for
x-pinch experiments was designed and constructed at Tsinghua University.
It is composed of a Marx generator, a combined pulse forming line (PFL), a
gas-filled V/N field distortion switch, a transfer line, and a
copper-sulphate resistive load for testing. The PPG-I implements a novel
design in lines that four pieces of waterline with impedance 5Ω in
parallel constitute a combined PFL with 1.25Ω, and incorporate each
other by a common self-break V/N switch on a matched 1.25Ω
transfer line. At the peak charging voltage of the PFL, the V/N switch
breaks down in multi-channel discharge mode, and electric energy is fed
into the testing load through the 1.25Ω transfer line. This article
presents the design and test of the PPG-I generator.
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