89 research outputs found
Floquet-surface bound states in the continuum in a resonantly driven 1D tilted defect-free lattice
We study the Floquet-surface bound states embedded in the continuum (BICs)
and bound states out the continuum (BOCs)in a resonantly driven 1D tilted
defect-free lattice. In contrast to fragile single-particle BICs assisted by
specially tailored potentials, we find that Floquet-surface BICs, stable
against structural perturbations, can exist in a wide range of parameter space.
By using a multiple-time-scale asymptotic analysis in the high-frequency limit,
the appearance of Floquet-surface bound states can be analytically explained by
effective Tamm-type defects at boundaries induced by the resonance between the
periodic driving and tilt. The phase boundary of existing Floquet-surface
states is also analytically given. Based on the repulsion effect of surface
states, we propose to detect transition points and measure the number of
Floquet-surface bound states by quantum walk. Our work opens a new door to
experimental realization of BICs in quantum system.Comment: 8 pages, 4 figures. submitted to Phys.Rev.
The dynamic effects of maternal high-calorie diet on glycolipid metabolism and gut microbiota from weaning to adulthood in offspring mice
Dysbiosis of gut microbiota can contribute to the progression of diabetes and obesity. Previous studies have shown that maternal high-fat (HF) diet during the perinatal period can alter the microbiota and induce metabolic disorders at weaning. However, whether dysbiosis of gut microbiota and metabolism could be recovered by a normal diet after weaning and the dynamic changes of gut microbiota have not been fully studied. In this study, C57BL/6J female mice were fed with a normal chow (NC) or HF diet for 4 weeks preconception, during gestation, and until pup weaning. After weaning, male offspring were fed with an NC diet until 9 weeks of age. The microbiota of offspring at weaning and 9 weeks of age was collected for 16S rRNA gene amplicon sequencing. We found that dams fed with an HF diet showed glucose intolerance after lactation. Compared with the offspring from NC dams, the offspring from HF dams exhibited a higher body weight, hyperglycemia, glucose intolerance, hyperinsulinemia, hypercholesterolemia, and leptin resistance and lower adiponectin at weaning. Fecal analysis indicated altered microbiota composition between the offspring of the two groups. The decrease in favorable bacteria (such as norank f Bacteroidales S24-7 group) and increase in unfavorable bacteria (such as Lachnoclostridium and Desulfovibrio) were strongly associated with a disturbance of glucose and lipid metabolism. After 6 weeks of normal diet, no difference in body weight, glucose, and lipid profiles was observed between the offspring of the two groups. However, the microbiota composition of offspring in the HF group was still different from that in the NC group, and microbiota diversity was lower in offspring of the HF group. The abundance of Lactobacillus was lower in the offspring of the HF group. In conclusion, a maternal HF diet can induce metabolic homeostasis and gut microbiota disturbance in offspring at weaning. Gut microbiota dysbiosis can persist into adulthood in the offspring, which might have a role in the promotion of susceptibility to obesity and diabetes in the later life of the offspring
Apolipoprotein E lipoprotein particles inhibit amyloid-β uptake through cell surface heparan sulphate proteoglycan
Binding affinity of heparin-apoE3 interaction. (A) Representative dot blot of heparin and apoE3 particles. Heparin was spotted onto nitrocellulose membrane along with mouse monoclonal anti-apoE antibody, WUE4, as a positive control and normal mouse IgG as a background. Membrane strips were incubated with increasing concentrations of apoE3 particles from immortalized astrocytes. Membrane-bound apoE was then visualized by biotin-conjugate anti-apoE antibody and infrared streptavidin secondary antibody. (B) Integrated infrared signal intensities from each dot were obtained and the average intensities from three independent experiments were plotted to acquire binding affinity curve and the dissociation constant (Kd). (TIF 2432Â kb
Compensatory Mechanisms Modulate the Neuronal Excitability in a Kainic Acid-Induced Epilepsy Mouse Model
Epilepsy is one of the most common neurological disorders affecting millions of people. Due to the complicated and unclear mechanisms of epilepsy, still a significant proportion of epilepsy patients remain poorly controlled. Epilepsy is characterized by convulsive seizures that are caused by increased excitability. In this study, by using kainic acid (KA)-induced epilepsy mice, we investigated the neuronal activities and revealed the neuronal compensatory mechanisms after KA-induced toxic hyperexcitability. The results indicate that both phasic inhibition induced by enhanced inhibitory synaptic activity and tonic inhibition mediated by activated astrocytes participate in the compensatory mechanisms. Compensatory mechanisms were already found in various neuronal disorders and were considered important in protecting nervous system from toxic hyperexcitability. This study hopefully will provide valuable clues in understanding the complex neuronal mechanisms of epilepsy, and exploring potential clinical treatment of the disease
Serum glucose, lactate dehydrogenase and hypertension are mediators of the 1 effect of body mass index on severity of COVID-19
Background: COVID-19 has a broad clinical specturm. We investigated the role of serum markers measured on admission on severity as assessed at discharge and investigated those which relate to the effect of BMI on severity. Methods: Clinical and laboratory data form 610 COVID-19 cases hospitalised in the province of Zheijang, China was investigated as risk factors for severe COVID-19 (assessed by respiratory distress) compared to mild or common forms using logistic regression methods. Biochemical markers were correlated with severity using spearman correlations and a ROC analysis was used to determine the individual contribution of each of the biochemical markers on severity. We carried out formal mediation analyses to investigate the extent of the effect of body mass index (BMI) on COVID-19 severity mediated by hypertension, glycemia, Lactose Dehydrogenase (LDH) at the time of hospitalisation and C-Reactive Protein levels (CRP), in units of standard deviations. Results: The individual markers measured on admission contributing most strongly to prediction of COVID-19 severity as assessed at discharge were LDH, CRP and glucose. The proportion of the effect of BMI on severity of COVID-19 mediated by CRP, glycemia or hypertension we find that glucose mediated 79% (
Apolipoprotein E lipoprotein particles inhibit amyloid-β uptake through cell surface heparan sulphate proteoglycan
Identification of a Novel Hemizygous SQSTM1 Nonsense Mutation in Atypical Behavioral Variant Frontotemporal Dementia
Frontotemporal dementia includes a large spectrum of neurodegenerative disorders. SQSTM1, coding for p62 protein, plays a vital role in the pathogenesis of FTD. Here, we report a case of a female patient with SQSTM1 mutation S224X, who was 59 years old when she initially exhibited memory decline, mild personality changes, and subtle atrophy of frontal/temporal lobes in magnetic resonance imaging (MRI). Genetic testing revealed a nonsense mutation of the SQSTM1 gene (S224X), resulting in premature termination of protein synthesis and a predicted truncated protein 217 amino acids shorter than the normal protein. Moreover, neither intact nor truncated SQSTM1 proteins was detectable in SQSTM1 S224X mutant overexpressing HEK-293T cells. We assayed for SQSTM1 cDNA in samples from the patient's peripheral leucocytes, and did not detect its mutation. The test of quantitative PCR showed significant decreased level of SQSTM1 mRNA from peripheral leucocytes of the patient compared to five dementia controls. Our results identify a novel pathogenic SQSTM1 S224X mutation in an atypical FTD patient accompanied with loss of SQSTM1/p62 protein expression probably due to SQSTM1 gene haploinsufficiency
Benefit and cost analysis of mariculture based on ecosystem services
As a life-supporting system, marine ecosystem provides various services for human being. Based on ecosystem services, we developed a Benifit and Cost Analysis model to balance the conflicts between economic income and environmental loss caused by mariculture activities. This model not only calculates market income of mariculture but also monetizes the positive and negative effects of mariculture activities on ecosystem services. In this model, three indices, the NPV (Net Present Value), BCR (Benefit to Cost Ratio) and RC (Relative Coefficent) with consideration of discount rate, are developed to assess and prioritize the candidate mariculture modes. This Benefit and Cost Analysis model was applied to Sanggou Bay, one typical mariculture bay in China, to identify sustainable mariculture mode. In this paper, we find that benefit and cost analysis based on ecosystem services value provides a convenient and effective tool to compare different exploitation modes of marine ecosystem.Beneft and cost analysis Marine ecosystem services Mariculture mode Sanggou Bay
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