Effect of Glucose Containing Crystalloid Infusion on Maternal Hemodynamic Status After Spinal Anesthesia for Cesarean Section.

BACKGROUND: Despite preventive strategies, hypotension is the most common complication of spinal anesthesia in cesarean section. OBJECTIVES: The aim of this study was to assess the effect of glucose-containing crystalloid infusion on maternal hemodynamic status after spinal anesthesia for cesarean section. METHODS: In this prospective, randomized, double-blind clinical trial, 80 parturients undergoing elective cesarean section with spinal anesthesia were studied. In group A (n = 40) ringer with 1% glucose solution (10 gr glucose in 1000 mL ringer) and in group B (n = 40) only ringer solution infused before and after spinal anesthesia. Demographic data, hemodynamic change, complications and their treatments, maternal blood sugar level and neonatal APGAR (appearance, pulse, grimace, activity and respiration) score, intraoperative fluid, duration of surgery, and anesthesia were recorded in the two groups. RESULTS: The incidence of hypotension in group A was significantly lower than group B (27.5% vs 75%) (P = 0.002). Other complications (sustained hypotension, nausea, pallor, and shivering were significantly lower in parturients of the group A (P < 0.05). Maternal blood sugar (BS), before and after surgery, was not significantly different in the two groups (P = 0.207 and P = 0.239, respectively). There was no statistically significant difference in the APGAR score of neonates at the 1st and 5th minutes of the birth between the two groups (P = 0.076). CONCLUSIONS: It seems that adding 1% glucose to crystalloid solution improves the hemodynamic status and decreases post-spinal anesthesia complications without significant changes in the maternal blood sugar level and APGAR score of neonates.

Effects of edge on graphene plasmons as revealed by infrared nanoimaging.

We used scattering-type scanning near-field optical microscopy (s-SNOM) to investigate the plasmonic properties of edges in well-defined graphene nanostructures, including sharp tapers, nanoribbons and nanogaps, which were all fabricated via the growth-etching chemical vapor deposition (GECVD) method. The obtained near-field images revealed the localized plasmon modes along the graphene nanoribbon; these modes strongly depended on the size of the graphene pattern, the angle of the tapered graphene and the infrared excitation wavelength. These interesting plasmon modes were verified by numerical simulations and explained by the reflection, and interference of electromagnetic waves at the graphene-SiO2 edge. The constructive interference at the graphene nanogap caused by charge accumulation was demonstrated for the first time. Using the infrared nanoimaging technique, greater plasmon broadening was observed in the zigzag edge than in the armchair edge. Our study suggests that graphene edges should be separated by an effective working distance to avoid the overlapping of localized plasmon modes, which is very important for the design of graphene-based plasmonic circuits and devices.

Spectral plasmonic effect in the nano-cavity of dye-doped nanosphere-based photonic crystals.

We demonstrated three-dimensional PMMA-based photonic crystal (3D-PC) nanostructures attached to Au nanoparticles (AuNPs), which undergo self-organization into super lattice planes and enhance the fluorescence properties. This new structure exhibited interesting tunable spectral, peak broadening plasmonic behavior because of strong plasmonic interaction at high laser powers. The presented work provides an important tool to improve the efficiency of dye laser applications.

Visible Surface Plasmon Modes in Single Bi2Te3 Nanoplate.

Searching for new plasmonic building blocks which offer tunability and design flexibility beyond noble metals is crucial for advancing the field of plasmonics. Herein, we report that solution-synthesized hexagonal Bi2Te3 nanoplates, in the absence of grating configurations, can exhibit multiple plasmon modes covering the entire visible range, as observed by transmission electron microscopy (TEM)-based electron energy-loss spectroscopy (EELS) and cathodoluminescence (CL) spectroscopy. Moreover, different plasmon modes are observed in the center and edge of the single Bi2Te3 nanoplate and a breathing mode is discovered for the first time in a non-noble metal. Theoretical calculations show that the plasmons observed in the visible range are mainly due to strong spin-orbit coupling induced metallic surface states of Bi2Te3. The versatility of shape- and size-engineered Bi2Te3 nanocrystals suggests exciting possibilities in plasmonics-enabled technology.

Enabling low amounts of YAG:Ce(3+) to convert blue into white light with plasmonic Au nanoparticles.

We report a new strategy to directly attach Au nanoparticles onto YAG:Ce(3+) phosphor via a chemical preparation method, which yields efficient and quality conversion of blue to yellow light in the presence of a low amount of phosphor. Photoluminescent intensity and quantum yield of YAG:Ce(3+) phosphor are significantly enhanced after Au nanoparticle modification, which can be attributed to the strongly enhanced local surface electromagnetic field of Au nanoparticles on the phosphor particle surface. The CIE color coordinates shifted from the blue light (0.23, 0.23) to the white light region (0.30, 0.33) with a CCT value of 6601 K and a good white light CRI value of 78, which indicates that Au nanoparticles greatly improve the conversion efficiency of low amounts of YAG:Ce(3+) in WLEDs.