Plasmonic Control of Radiative Properties of Semiconductor Quantum Dots Coupled to Plasmonic Ring Cavities

In recent years, a lot of effort has been made to achieve controlled delivery of target particles to the hotspots of plasmonic nanoantennas, in order to probe and/or exploit the extremely large field enhancements produced by such structures. While in many cases such high fields are advantageous, there are instances where they should be avoided. In this work, we consider the implications of using the standard nanoantenna geometries when colloidal quantum dots are employed as target entities. We show that in this case, and for various reasons, dimer antennas are not the optimum choice. Plasmonic ring cavities are a better option despite low field enhancements, as they allow collective coupling of many quantum dots in a reproducible and predictable manner. In cases where larger field enhancements are required, or for larger quantum dots, nonconcentric ring-disk cavities can be employed instead

Numerical Simulation of Electron Energy Loss Spectroscopy of Aluminum Nanodisk Surface Plasmons

We perform simulations to model electron energy loss spectroscopy of aluminum nanodisk surface plasmons. Nanodisk geometry and e-beam position determine excitation and energy of plasmonic modes. Multipolar modes are explained with a circulating waveguide model

Balanced and unbalanced solutions modulate the release of Matrix Metalloproteinase-9 (MMP-9) from neutrophils in response to inflammatory stimuli: an in vitro study

We investigated the effect of balanced (BS) and unbalanced (UBS) solutions in the absence or presence of hydroxyethyl starch (HES) on neutrophil functionality, evaluating the release of matrix metalloproteinase (MMP)-9, myeloperoxidase (MPO), and MMP-8.Neutrophils were isolated by gradient centrifugation and dextran sedimentation and incubated in BS or UBS without or with HES, in the absence or presence of Interleukin-8 (IL-8) or Lipopolysaccharide (LPS). MMP-9, MPO, and MMP-8 were assayed by commercially available ELISA kits.There was not any influence of volume replacement solutions on the release of the enzymes from resting neutrophils. After IL-8 stimulation, the release of MMP-9 was higher in BS than in UBS or RPMI-1640, whereas HES enhanced its release regardless of the composition. After LPS stimulation, the release of MMP-9 was higher in both UBS and BS than RPMI-1640, but HES brought its release back to physiological conditions. No difference was found in the release of MPO and MMP-8 after stimulation with IL-8 or LPS.Volume replacement solutions might have an impact on the release of MMP-9 depending on the inflammatory milieu, suggesting that the use of balanced or unbalanced solutions is not a neutral choice

Effects of two different strategies of fluid administration on inflammatory mediators, plasma electrolytes and acid/base disorders in patients undergoing major abdominal surgery: a randomized double blind study.

Administration of normal saline might increase circulating levels of pro-inflammatory cytokines and may cause variation of plasmatic electrolytic and hyperchloremic acidosis, which in turn can impair renal function. Hence the use of balanced solutions could influence the inflammatory cascade triggered by the surgical procedures, the plasmatic electrolyte concentration, the acid--base equilibrium, and the renal function.This is a double blind randomized trial. Forty patients undergoing major abdominal surgery (bowel cancer) were allocated in two groups, the balanced solution (BS) group in which the fluids administered were balanced solutions (colloids and crystalloids); and the unbalanced solution (UBS) group in which the fluids administered were unbalanced solutions (colloids and crystalloids). Measurements were performed after anaesthesia induction (T0), at the end of surgery (T1), within 2 h after surgery (T2) and 24 h after the beginning of surgery (T3). The following data were collected: 1) active matrix metalloproteinase 9 (MMP-9) and its tissue inhibitor (TIMP-1), IL-6, IL-8, IL-10; 2) blood gases variables; 3) electrolytes, albumin, total serum protein and the strong ion difference; 4) neutrophil gelatinase-associated lipocalin (NGAL) from urinary sample.The BS group exhibited higher circulating level of IL-10 and TIMP-1 and lower level of active MMP-9. The UBS group experienced hypercloremia, hypocalcemia, hypomagnesemia, worse acid--base equilibrium and higher level of NGAL.The use of balanced solutions was responsible of less alteration of plasmatic electrolytes, acid--base equilibrium, kidney function and it might be associated with an early anti-inflammatory mechanisms triggering.Trial registrationClinicalTrials.gov (Ref: NCT01320891)

Influence of different strategies of volume replacement on the activity of matrix metalloproteinases: an in vitro and in vivo study

Background: Excessive production of matrix metalloproteinase 9 (MMP-9) is linked to tissue damage and anastomotic leakage after large bowel surgery. Hence the aim of this study was to verify whether different strategies of fluids administration can reduce the MMP-9 expression. Methods: 1) In vitro experiment: we tested the hypothesis of a direct inhibition of MMP-9 by the fluids used perioperatively, i.e. lactated Ringer’s solution, poligeline 3.4%, and the hydroxyethyl starch 130/0.4; 2) In vivo experiment: thirty-six patients undergoing surgery for colon cancer were randomized to three different groups to receive either lactated Ringer’s solution, poligeline or hydroxyethyl starch. MMP-9 and tissue inhibitor of metalloproteinases were measured from venous blood samples; MMP-9/tissue inhibitor of metalloproteinases ratio was calculated as an index of equilibrium between the action of MMP-9 and its inhibition. Results: 1) In vitro experiment: the presence of hydroxyethyl starch 130/0.4 in the MMP9 assay system showed a strong inhibition of the enzymatic activity compared to lactated Ringer’s solution; 2) In vivo experiment: MMP-9 and tissue inhibitor of metalloproteinases plasma levels did not differ among the three groups at the baseline while those levels increased significantly at the end of surgery. At this time, the MMP-9 plasma levels as well as MMP-9/tissue inhibitor of metalloproteinases ratio were significantly higher in lactated Ringer’s solution and poligeline groups than in hydroxyethyl starch group. These results were confirmed 72 h after surgery. Conclusions: Our study demonstrates that the hydroxyethyl starch 130/04 decreases the circulating levels of MMP-9 in patients undergoing abdominal surgery