Dexmedetomidine reduces acute kidney injury after endovascular aortic repair of Stanford type B aortic dissection: A randomized, double-blind, placebo-controlled pilot study.

STUDY OBJECTIVE: To determine the effect of dexmedetomidine on acute kidney injury (AKI) following endovascular aortic repair (EVAR) for Stanford type B aortic dissection (TBAD). DESIGN: Randomized, double-blind, placebo-controlled, pilot study. SETTING: University Hospital. PATIENTS: 102 TBAD patients undergoing EVAR procedures were enrolled. Patients with dissection involving aortic arch or renal artery were excluded. INTERVENTIONS: Patients were randomly assigned, in a 1:1 ratio, to a dexmedetomidine group (intravenous dexmedetomidine 0.4 µg/kg/h immediately after anesthesia induction and 0.1 µg/kg/h after extubation, which was maintained until 24 h) or a normal saline control group. MEASUREMENTS: The primary outcome was the incidence of AKI within the first two days after surgery, based on the Acute Kidney Injury Network (AKIN) criteria. The secondary outcomes included serum cystatin C and estimated glomerular filtration rate on postoperative days 1, 2, and 7, and in-hospital need for renal replacement therapy (RRT). Long-term outcomes included RRT and all-cause mortality. MAIN RESULTS: Ninety-eight patients completed the study (dexmedetomidine, n = 48; control, n = 50). AKIN stage 1 AKI occurred in 3/48 (6.3%) patients receiving dexmedetomidine, compared with 11/50 (22%) patients receiving normal saline (odds ratio = 0.24, 95% CI: 0.07 to 0.89, P = 0.041). This difference remained significant after adjusting for baseline covariates (adjusted odds ratio = 0.21, 95% CI: 0.05 to 0.84; P = 0.028). Dexmedetomidine led to a lower serum cystatin C on postoperative day 1 (median [IQR] mg/L: 1.31 [1.02-1.72] vs. 1.58 [1.28-1.96]). There were no between-group differences in other secondary or long-term outcomes. During the follow-up (median = 28.4 months), 1 patient in the dexmedetomidine group and 3 patients in the control group required RRT. CONCLUSIONS: Dexmedetomidine reduced the incidence of AKI in TBAD patients after EVAR procedures. The long-term benefits of dexmedetomidine in this patient population warrant further investigation. TRIAL REGISTRATION: ChiCTR-IPR-15006372.

[Green synthesis of silver nanoparticles and their application in SERS].

In the present paper, we have successfully synthesized silver nancomparticles by reducing of silver nitrate in alkaline solution via 60 degrees C water bath for 20 minutes with the use of tyrosine, a nontoxic and green macromolecule, as a reducing and stabilizing agent. The formation of silver nanoparticles was observed visually by color change of the solutions (from faint yellow to brown yellow). The morphologies of the Ag NPs were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy (TEM). The UV-Vis absorption peak of silver nanoparticles located at 412 nm. The TEM image of silver nanoparticles indicated that the diameters of nanospheres are mainly in the range 15-25 nm. In order to evaluate the SERS activity of the silver nancomparticles, crystal violet and folic acid were used as the Raman probe molecule. The experimental results indicated that there are two ascendancies, firstly, the approach is convenient and the reaction condition is facile, secondly, tyrosine is a water-soluble, nontoxic and biodegradable macromolecule, which makes this approach provide a green strategy to prepare Ag NPs. Significantly, the synthesized Ag NPs exhibits good surface enhanced Raman scattering (SERS) activity as SERS substrates to detect crystal violet and folic acid in aqueous solution.