8 research outputs found
Novel sample-substrates for the determination of new psychoactive substances in oral fluid by desorption electrospray ionization-high resolution mass spectrometry
A reliable screening and non invasive method based on the use of microextraction by packed sorbent coupled
with desorption electrospray ionization-high resolution mass spectrometry was developed and validated for the
detection of new psychoactive substances in oral fluid. The role of different sample substrates in enhancing
signal intensity and stability was evaluated by testing the performances of two polylactide-based materials, i.e.
non-functionalized and functionalized with carbon nanoparticles, and a silica-based material compared to
commercially available polytetrafluorethylene supports. The best results were achieved by using the nonfunctionalized
polylactide substrates to efficiently ionize compounds in positive ionization mode, whereas the
silica coating proved to be the best choice for operating in negative ionization mode. LLOQs in the low μg/L, a
good precision with CV% always lower than 16% and RR% in the 83(±4)-120(±2)% range, proved the
suitability of the developed method for the determination of the analytes in oral fluid. Finally, the method was
applied for screening oral fluid samples for the presence of psychoactive substances during private parties,
revealing mephedrone in only one sample out of 40 submitted to analysis
Construction of Bioactive and Reinforced Bioresorbable Nanocomposites by Reduced Nano-Graphene Oxide Carbon Dots
Bioactive
and reinforced poly(ε-caprolactone) (PCL) films
were constructed by incorporation of cellulose derived reduced nanographene
oxide (r-nGO) carbon nanodots. Two different microwave-assisted reduction
routes in superheated water were utilized to obtain r-nGO and r-nGO-CA.
For the latter, a green reducing agent caffeic acid (CA), was incorporated
in the reduction process. The materials were extruded and compression
molded to obtain proper dispersion of the carbon nanodots in the polymer
matrix. FTIR results revealed favorable interactions between r-nGO-CA
and PCL that improved the dispersion of r-nGO-CA. r-nGO, and r-nGO-CA
endorsed PCL with several advantageous functionalities including improved
storage modulus and creep resistance. The considerable increase in
storage modulus demonstrated that the carbon nanodots had a significant
reinforcing effect on PCL. The PCL films with r-nGO-CA were also evaluated
for their osteobioactivity and cytocompatibility. Bioactivity was
demonstrated by formation of hydroxyapatite (HA) minerals on the surface
of r-nGO-CA loaded nanocomposites. At the same time, the good cytocompatibility
of PCL was retained as illustrated by the good cell viability
to MG63 osteoblast-like cells giving promise for bone tissue engineering
applications
Green Strategy to Reduced Nanographene Oxide through Microwave Assisted Transformation of Cellulose
A green
strategy for fabrication of biobased reduced nanographene
oxide (r-nGO) was developed. Cellulose derived nanographene oxide
(nGO) type carbon nanodots were reduced by microwave assisted hydrothermal
treatment with superheated water alone or in the presence of caffeic
acid (CA), a green reducing agent. The carbon nanodots, r-nGO and
r-nGO-CA, obtained through the two different reaction routes without
or with the added reducing agent, were characterized by multiple analytical
techniques including FTIR, XPS, Raman, XRD, TGA, TEM, AFM, UV–vis,
and DLS to confirm and evaluate the efficiency of the reduction reactions.
A significant decrease in oxygen content accompanied by increased
number of sp<sup>2</sup> hybridized functional groups was confirmed
in both cases. The synergistic effect of superheated water and reducing
agent resulted in the highest C/O ratio and thermal stability, which
also supported a more efficient reduction. Interesting optical properties
were detected by fluorescence spectroscopy where nGO, r-nGO, and r-nGO-CA
all displayed excitation dependent fluorescence behavior. r-nGO-CA
and its precursor nGO were evaluated toward osteoblastic cells MG-63
and exhibited nontoxic behavior up to 200 μg mL<sup>–1</sup>, which gives promise for utilization in biomedical applications
International Nosocomial Infection Control Consortiu (INICC) report, data summary of 43 countries for 2007-2012. Device-associated module
We report the results of an International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2007-December 2012 in 503 intensive care units (ICUs) in Latin America, Asia, Africa, and Europe. During the 6-year study using the Centers for Disease Control and Prevention's (CDC) U.S. National Healthcare Safety Network (NHSN) definitions for device-associated health care–associated infection (DA-HAI), we collected prospective data from 605,310 patients hospitalized in the INICC's ICUs for an aggregate of 3,338,396 days. Although device utilization in the INICC's ICUs was similar to that reported from ICUs in the U.S. in the CDC's NHSN, rates of device-associated nosocomial infection were higher in the ICUs of the INICC hospitals: the pooled rate of central line–associated bloodstream infection in the INICC's ICUs, 4.9 per 1,000 central line days, is nearly 5-fold higher than the 0.9 per 1,000 central line days reported from comparable U.S. ICUs. The overall rate of ventilator-associated pneumonia was also higher (16.8 vs 1.1 per 1,000 ventilator days) as was the rate of catheter-associated urinary tract infection (5.5 vs 1.3 per 1,000 catheter days). Frequencies of resistance of Pseudomonas isolates to amikacin (42.8% vs 10%) and imipenem (42.4% vs 26.1%) and Klebsiella pneumoniae isolates to ceftazidime (71.2% vs 28.8%) and imipenem (19.6% vs 12.8%) were also higher in the INICC's ICUs compared with the ICUs of the CDC's NHSN