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BackgroundDiabetic retinopathy (DR) is a common complication of diabetic patients. Retinal physiological function is affected by hydration status. We aimed to explore the association between hydration status and DR.MethodsNational Health and Nutrition Examination Survey (NHANES) 2005-2008 was used to perform this cross-sectional study. Serum osmolality was used to assess hydration status for all participants and calculated osmolality was evaluated for only older people. DR and its severity were evaluated and graded into mild non-proliferative retinopathy, moderate/severe non-proliferative retinopathy, and proliferative diabetic retinopathy by the Early Treatment for Diabetic Retinopathy Study protocol and NHANES Digital Grading Protocol. Fully adjusted multivariable logistic regression models were used by SAS OnDemand for Academics.ResultsAmong the 5,220 United States adults aged 40 or older, compared with the lowest osmolality group, participants with the highest quartile of serum osmolarity had higher odds of DR (OR: 1.371, 95% CI: 1.001–1.876). For participants with DR, the adjusted OR (95 % CI) of moderate/severe non-proliferative retinopathy and proliferative diabetic retinopathy in the higher serum osmolarity group was 2.119 (1.200–3.741) and 7.001 (3.175–15.438), respectively. Furthermore, in older people, higher calculated osmolarity was significantly associated with increased occurrence of DR (OR: 2.039, 95% CI: 1.305–3.186).ConclusionsAdults with lower hydration status had higher risk of DR, moderate/severe non-proliferative retinopathy, and proliferative diabetic retinopathy. Dehydration in older adults, classified by calculated osmolality, is associated with a higher rate of DR. There was consistent trend in the results between the two methods.

L-shaped columns composed of concrete-filled steel tubes (LCFST columns) connected by steel plates, which are important component to make sure the mono-column working together, were investigated under axial loading experiment with different width and thickness of connection plates. The relationships between load and longitudinal displacement, lateral displacement, longitudinal strains and transverse strains as well as failure mode are presented. Load carrying capacity of LCFST columns increased with the width and thickness of the connection plates increasing. In addition, the integrity of the specimen was improved with increase of thickness and decrease of width of the connection plates. Failure modes obtained from the finite element model were consistent with the phenomenon observed in the test. Besides, the parameters of slenderness ratio, dimensions of connection plate, and transverse stiffener spacing were analyzed. Finally, the calculating method of yield bearing capacity of axial compression was proposed based on the former analysis.

Optical sensors with local surface plasmon resonance (LSPR) of noble metal (gold, silver, platinum) nanoparticles have received extensive attention due to their excellent detection performance. Here, we propose an LSPR fiber-optic sensor with a graphene oxide/triangular silver nanoparticle structure. Benefiting from the LSPR characteristics of the silver triangle nanoparticles, the use of triangular silver nanoparticles provides significant sensitivity enhancement. In order to highlight the enhancement of silver triangle nanoparticles, we chose the commonly used silver spherical nanoparticles as a comparison. We used the finite difference time domain method to model and calculate the local electric field and extinction efficiency for the two shapes of silver nanoparticles. The simulation results show that the local electric field intensity of triangular silver nanoparticles is 10 times that of spherical silver nanoparticles, and the extinction efficiency is 4 times that of spherical silver nanoparticles. In the experiment, a U-shaped LSPR fiber sensor with spherical and triangular silver nanoparticles was fabricated. The former has a refractive index sensitivity of 342.7 nm/RIU and the latter has a sensitivity of 1116.8 nm/RIU. Even if there is temperature interference during the detection process, the detection result will not produce a large error.