ABSTRACT
The flexibly manipulated terahertz wave is currently a hot research topic. To address this challenge, we proposed an all-dielectric coding metasurface for shaping the terahertz wave including beam splitting, beam deflection, vortex beam generators, and a vortex beam and multi-beam splitting combination by combining addition with the convolution theorem. This work represents what we believe to be a new method of combining terahertz wave regulation with digital signal processing and opens up the versatile design ideas of multifunctional metadevices.
ABSTRACT
The conventional transmission and reflection operating mode switching metasurface depends on phase change materials, which are often difficult to integrate with metasurface devices and work in real time. Here, we propose an integration of a transmission-reflection metasurface that can dynamically control beam direction and functions in both transmission and reflection modes by varying the frequency of the incident wave. Remarkably, the transmission and reflection modes of terahertz beam manipulation can be obtained by illuminating only the transmission side of the metasurface. The full-wave simulation results are in good agreement with the theoretically calculated results, which verifies the terahertz wave manipulation capability of the proposed structure. This metasurface provides a design method for full-space terahertz beam regulation devices.
ABSTRACT
<p><b>OBJECTIVE</b>This study was conducted to compare serum cytosolic β-glucosidase (CBG) levels of age-matched control patients with those of infants with necrotizing enterocolitis (NEC) thereby to determine the eventual association between serum CBG levels with extensive disease in infants with NEC.</p><p><b>METHOD</b>A total of 96 premature infants were divided into the early NEC group (n = 25), confirmed NEC group (n = 23) and the control group (n = 48). Serum CBG concentration, C-reactive protein (CRP) and peripheral blood white blood cells (WBC) were measured at the onset of the disease in patients in early NEC or confirmed NEC groups and at weeks 2-3 in control infants. Data were analyzed using descriptive statistics, non-parametric tests, Student's t-test, linear correlation, Spearman correlation analysis, receiver operating characteristic (ROC) curve were used for statistical analysis.</p><p><b>RESULTS</b>The median birth weights (mean ± SE) in the three groups were not statistically significant (P > 0.05). Serum CBG concentration in the 3 groups were (112.369 ± 108.539) nmol/L, (693.013 ± 211.614) nmol/L and (36.478 ± 28.31) nmol/L, respectively. The infants in the confirmed NEC group had highest CBG levels, compared with the other 2 groups (P < 0.05). When the levels of CBG ≥ 65 ng/ml, CRP ≥ 2 mg/L and WBC < 5 × 10(9)/L within 3 days after birth or > 20 × 10(9)/L 3 days after birth were considered as positive parameters, the sensitivity of CBG and CRP was higher than that of WBC (P < 0.05). Among these indices, CBG had the highest specificity (87.4%), positive predictive (95.6%) and Youden's index (81.3%). CBG is correlated with CRP (the Spearman correlation coefficient was 0.379, P < 0.01).</p><p><b>CONCLUSION</b>Serum CBG concentration increases early in NEC. Serum CBG level was associated with extensive disease in infants with NEC. Therefore CBG can be used as a marker in the early diagnosis of NEC.</p>
Subject(s)
Humans , Infant, Newborn , Case-Control Studies , Enterocolitis, Necrotizing , Blood , Diagnosis , Infant, Premature , Leukocyte Count , Serum , Metabolism , beta-Glucosidase , BloodABSTRACT
Objective To explore the effects of the neonatal handling and enriched environmental stimulation on brain damage in neonatal rats with hypoglycemia.Methods Thirty-six neonatal rats were randomly divided into the normal group,hypoglycemia intervention group and the hypoglycemia non-intervention group.Those rats in hypoglycemia intervention and hypoglycemia non-intervention groups were weaned for 12 h,then the blood sugar of both groups were monitored.After neonatal rat models with hyperglycemia were prepared,the rats in hypoglycemia intervention group received the neonatal handling for 14 d and then were kept in an enriched stimulation environment for another 14 d.Rats in normal group and hypoglycemia non-intervention group were fed in the routine way.Neonatal handling was done when the rats were born for 24 h.The rat was rubbed with the brush from head to tail softly.Rats in the hypoglycemia non-intervention group was not handled.The enriched environment stimulation was used after 15 d when the rats were born.Rats in the hypoglycemia intervention group was put into the enriched environment for 1 h per day until 28 d when the rats were born,and rats in the hypoglycemia non-intervention group was put into the normal environment.Then the body weight was scaled at 0 d,7 d,14 d,21 d and 28 d when the rats were born.Space learning and memory were tested with Morris earter at their third month's age.After that,changes of pathology was observed in their occipital cortex.Results The weight increase,the ability of space learning,memory and the number of survival pyramid neurons of occipital cortex in normal group were better than those in hypoglycemia intervention and hypoglycemia non-intervention group(Pa
