Trends in the Prevalence of Metabolically Healthy Obesity Among US Adults, 1999-2018.

Importance: Improved understanding of trends in the proportion of individuals with metabolically healthy obesity (MHO) may facilitate stratification and management of obesity and inform policy efforts. Objectives: To characterize trends in the prevalence of MHO among US adults with obesity, overall and by sociodemographic subgroups. Design, Setting, and Participants: This survey study included 20 430 adult participants from 10 National Health and Nutrition Examination Survey (NHANES) cycles between 1999-2000 and 2017-2018. The NHANES is a series of cross-sectional and nationally representative surveys of the US population conducted continuously in 2-year cycles. Data were analyzed from November 2021 to August 2022. Exposures: National Health and Nutrition Examination Survey cycles from 1999-2000 to 2017-2018. Main Outcomes and Measures: Metabolically healthy obesity was defined as a body mass index of 30.0 (calculated as weight in kilograms divided by height in meters squared) without any metabolic disorders in blood pressure, fasting plasma glucose (FPG), high-density lipoprotein cholesterol (HDL-C), or triglycerides based on established cutoffs. Trends in the age-standardized prevalence of MHO were estimated using logistic regression analysis. Results: This study included 20 430 participants. Their weighted mean (SE) age was 47.1 (0.2) years; 50.8% were women, and 68.8% self-reported their race and ethnicity as non-Hispanic White. The age-standardized prevalence (95% CI) of MHO increased from 3.2% (2.6%-3.8%) in the 1999-2002 cycles to 6.6% (5.3%-7.9%) in the 2015-2018 cycles (P < .001 for trend). There were 7386 adults with obesity. Their weighted mean (SE) age was 48.0 (0.3) years, and 53.5% were women. The age-standardized proportion (95% CI) of MHO among these 7386 adults increased from 10.6% (8.8%-12.5%) in the 1999-2002 cycles to 15.0% (12.4%-17.6%) in the 2015-2018 cycles (P = .02 for trend). Substantial increases in the proportion of MHO were observed for adults aged 60 years or older, men, non-Hispanic White individuals, and those with higher income, private insurance, or class I obesity. In addition, there were significant decreases in the age-standardized prevalence (95% CI) of elevated triglycerides (from 44.9% [40.9%-48.9%] to 29.0% [25.7%-32.4%]; P < .001 for trend) and reduced HDL-C (from 51.1% [47.6%-54.6%] to 39.6% [36.3%-43.0%]; P = .006 for trend). There was also a significant increase in elevated FPG (from 49.7% [95% CI, 46.3%-53.0%] to 58.0% [54.8%-61.3%]; P < .001 for trend) but no significant change in elevated blood pressure (from 57.3% [53.9%-60.7%] to 54.0% [50.9%-57.1%]; P = .28 for trend). Conclusions and Relevance: The findings of this cross-sectional study suggest that the age-standardized proportion of MHO increased among US adults from 1999 to 2018, but differences in trends existed across sociodemographic subgroups. Effective strategies are needed to improve metabolic health status and prevent obesity-related complications in adults with obesity.

Retinal blood vessel segmentation based on Densely Connected U-Net.

The segmentation of blood vessels from retinal images is an important and challenging task in medical analysis and diagnosis. This paper proposes a new architecture of the U-Net network for retinal blood vessel segmentation. Adding dense block to U-Net network makes each layer's input come from the all previous layer's output which improves the segmentation accuracy of small blood vessels. The effectiveness of the proposed method has been evaluated on two public datasets (DRIVE and CHASE_DB1). The obtained results (DRIVE： Acc = 0.9559， AUC = 0.9793， CHASE_DB1： Acc = 0.9488， AUC = 0.9785) demonstrate the better performance of the proposed method compared to the state-of-the-art methods. Also, the results show that our method achieves better results for the segmentation of small blood vessels and can be helpful to evaluate related ophthalmic diseases.

New Signal Amplification Strategy Using Semicarbazide as Co-reaction Accelerator for Highly Sensitive Electrochemiluminescent Aptasensor Construction.

A highly sensitive electrochemiluminescent (ECL) aptasensor was constructed using semicarbazide (Sem) as co-reaction accelerator to promote the ECL reaction rate of CdTe quantum dots (CdTe QDs) and the co-reactant of peroxydisulfate (S2O8(2-)) for boosting signal amplification. The co-reaction accelerator is a species that when it is introduced into the ECL system containing luminophore and co-reactant, it can interact with co-reactant rather than luminophore to promote the ECL reaction rate of luminophore and co-reactant; thus the ECL signal is significantly amplified in comparison with that in which only luminophore and co-reactant are present. In this work, the ECL signal probes were first fabricated by alternately assembling the Sem and Au nanoparticles (AuNPs) onto the surfaces of hollow Au nanocages (AuNCs) via Au-N bond to obtain the multilayered nanomaterials of (AuNPs-Sem)n-AuNCs for immobilizing amino-terminated detection aptamer of thrombin (TBA2). Notably, the Sem with two -NH2 terminal groups could not only serve as cross-linking reagent to assemble AuNPs and AuNCs but also act as co-reaction accelerator to enhance the ECL reaction rate of CdTe QDs and S2O8(2-) for signal amplification. With the sandwich-type format, TBA2 signal probes could be trapped on the CdTe QD-based sensing interface in the presence of thrombin (TB) to achieve a considerably enhanced ECL signal in S2O8(2-) solution. As a result, the Sem in the TBA2 signal probes could accelerate the reduction of S2O8(2-) to produce the more oxidant mediators of SO4(•-), which further boosted the production of excited states of CdTe QDs to emit light. With the employment of the novel co-reaction accelerator Sem, the proposed ECL biosensor exhibited ultrahigh sensitivity to quantify the concentration of TB from 1 × 10(-7) to 1 nM with a detection limit of 0.03 fM, which demonstrated that the co-reaction accelerator could provide a simple, efficient, and low-cost approach for signal amplification and hold great potential for other ECL biosensors construction.

An amplified electrochemiluminescent aptasensor using Au nanoparticles capped by 3,4,9,10-perylene tetracarboxylic acid-thiosemicarbazide functionalized C60 nanocomposites as a signal enhancement tag.

A novel electrochemiluminescent (ECL) signal tag of Au nanoparticles capped by 3,4,9,10-perylene tetracarboxylic acid-thiosemicarbazide functionalized C60 nanocomposites (AuNPs/TSC-PTC/C60NPs) was developed for thrombin (TB) aptasensor construction based on the peroxydisulfate/oxygen (S2O8(2-)/O2) system. For signal tag fabrication, the C60 nanoparticles (C60NPs) were prepared and then coated with 3,4,9,10-perylene tetracarboxylic acid (PTCA) by π-π stacking interactions. Afterwards, thiosemicarbazide (TSC) was linked with PTCA functionalized C60NPs via amidation for further assembling Au nanoparticles (AuNPs). Finally, detection aptamer of thrombin (TBA 2) was labeled on the ECL signal amplification tag of AuNPs/TSC-PTC/C60NPs. Herein, TSC, with the active groups of -NH2 and -SH, was selected and introduced into the ECL S2O8(2-)/O2 system for the first time, which could not only offer the active groups of -SH to absorb AuNPs for TBA 2 anchoring but also remarkably enhance the ECL signal of the S2O8(2-)/O2 system by the formation of TSC-PTC/C60NPs for signal amplification. Meanwhile, the sensing interface of a glassy carbon electrode (GCE) was modified by AuNPs/graphene (AuNPs/GR) nanocomposites with the large specific surface area and the active sites, followed by immobilization of thiol-terminated thrombin capture aptamer (TBA 1). With the formation of the sandwich-type structure of TBA 1, TB, and TBA 2 signal probes, a desirable enhanced ECL signal was measured in the testing buffer of an S2O8(2-)/O2 solution for detecting TB. The aptasensor exhibited a good linear relationship for TB detection in the range of 1 × 10(-5)-10 nM with a detection limit of 3.3 fM.

Amplified electrochemiluminescent aptasensor using mimicking bi-enzyme nanocomplexes as signal enhancement.

In this work, a sandwich-type electrochemiluminescence (ECL) aptasensor for ultrasensitive detection of thrombin (TB) was designed based on mimicking bi-enzyme cascade catalysis to in situ generate coreactant of dissolved oxygen (O2) for signal amplification. We utilized hollow Au nanoparticles (HAuNPs) as carriers to immobilize glucose oxidase nanoparticles (GOxNPs) and Pt nanoparticles (PtNPs) by electrostatic adsorption. Then, the detection aptamer of thrombin (TBA 2) was immobilized on the PtNPs/GOxNPs/HAuNPs nanocomplexes. Finally, hemin was intercalated into the TBA 2 to obtain the hemin/G-quadruplex structure. The hemin/G-quadruplex was an interesting DNAzyme that commonly mimiced horseradish peroxidase (HRP). Herein, GOxNPs, hemin/G-quadruplex and PtNPs could form mimicking bi-enzyme cascade catalysis system to in situ generate dissolved O2 as coreactant in peroxydisulfate solution when the testing buffer contained proper amounts of glucose. This method had successfully overcome the disadvantage of difficulty to label the dissolved O2 and realized the ECL signal amplification. The experiment proved that the aptasensor had good linear relationship on low concentration of TB. The linear range was 1×10(-6)-10 nM, with a detection limit of 0.3 fM.