7 research outputs found
Condiciones Laborales y de Salud de Los Trabajadores de la Maquila del Tabaco. Ciudad El Paraíso, Honduras. Octubre 2003 a Marzo 2004.
El propósito es describir las características socio demográficas, las condiciones de trabajo y situación de salud de los trabajadores para aportar información y conocer la magnitud y trascendencia de esta problemática y tomar decisiones necesarias de prevención
Potential-Modulated Electrochemiluminescence of Carbon Nitride Nanosheets for Dual-Signal Sensing of Metal Ions
As
an emerging semiconductor, graphite-phase polymeric carbon nitride
(GPPCN) has drawn much attention not only in photocatalysis but also
in optical sensors such as electrochemiluminescence (ECL) sensing of
metal ions. However, when the concentrations of interfering metal
ions are several times higher than that of the target metal ion, it
is almost impossible to distinguish which metal ion changes the ECL
signals in real sample detection. Herein, we report that the dual-ECL
signals could be actuated by different ECL reactions merely from GPPCN
nanosheets at anodic and cathodic potentials, respectively. Interestingly,
the different metal ions exhibited distinct quenching/enhancement
of the ECL signal at different driven potentials, presumably ascribed
to the diversity of energy-level matches between the metal ions and
GPPCN nanosheets and catalytic interactions of the intermediate species
in ECL reactions. On this basis, without any labeling and masking
reagents, the accuracy and reliability of sensors based on the ECL
of GPPCN nanosheets toward metal ions were largely improved; thus,
the false-positive result caused by interferential metal ions could
be effectively avoided. As an example, the proposed GPPCN ECL sensor
with a detection limit of 1.13 nM was successfully applied for the
detection of trace Ni<sup>2+</sup> ion in tap and lake water
Reversible Assembly of Graphitic Carbon Nitride 3D Network for Highly Selective Dyes Absorption and Regeneration
Responsive
assembly of 2D materials is of great interest for a
range of applications. In this work, interfacial functionalized carbon
nitride (CN) nanofibers were synthesized by hydrolyzing bulk CN in
sodium hydroxide solution. The reversible assemble and disassemble
behavior of the as-prepared CN nanofibers was investigated by using
CO<sub>2</sub> as a trigger to form a hydrogel network at first. Compared
to the most widespread absorbent materials such as active carbon,
graphene and previously reported supramolecular gel, the proposed
CN hydrogel not only exhibited a competitive absorbing capacity (maximum
absorbing capacity of methylene blue up to 402 mg/g) but also overcame
the typical deficiencies such as poor selectivity and high energy-consuming
regeneration. This work would provide a strategy to construct a 3D
CN network and open an avenue for developing smart assembly for potential
applications ranging from environment to selective extraction
Metal-Free All-Carbon Nanohybrid for Ultrasensitive Photoelectrochemical Immunosensing of alpha-Fetoprotein
C<sub>60</sub> can accept up to six electrons reversibly and show
exceptional light absorption over the entire UV–vis spectrum,
making it a potential photoactive probe for photoelectrochemical (PEC)
bioassay. However, few successful works have been reported to apply
fullerenes in PEC biosensing, partially because of the low electronic
conductivity and poor interfacial interactions with targeted biomolecules.
Herein, we report the addressing of these two obstacles by coupling
high conductive graphite flake (Gr), graphene oxide (GO) with sufficient
oxygen-containing functional groups, and an alkylated C<sub>60</sub> (AC<sub>60</sub>) into a metal-free all-carbon nanohybrid (AC<sub>60</sub>-Gr-GO) via harnessing delicate noncovalent interactions
among them through a facile mechanical grinding. It was revealed that
the as-obtained AC<sub>60</sub>-Gr-GO nanohybrid not only showed conspicuous
enhancement of photocurrent up to 35 times but also offered rich anchors
for bioconjugation. With detection of alpha-fetoprotein as an example,
the AC<sub>60</sub>-Gr-GO based PEC immunosensor demonstrated a broad
linear detection range (1 pg·mL<sup>–1</sup> to 100 ng·mL<sup>–1</sup>) and a detection limit as low as 0.54 pg·mL<sup>–1</sup>, superior/competitive to PEC immunosensors for AFP
in previous reports. By a proper reinforcement in conductivity and
biointerface engineering, this work may provide a new way to use fullerenes
as photoactive materials in more general PEC biosensing
Chemically Modulated Carbon Nitride Nanosheets for Highly Selective Electrochemiluminescent Detection of Multiple Metal-ions
Chemical
structures of two-dimensional (2D) nanosheet can effectively
control the properties thus guiding their applications. Herein, we
demonstrate that carbon nitride nanosheets (CNNS) with tunable chemical
structures can be obtained by exfoliating facile accessible bulk carbon
nitride (CN) of different polymerization degree. Interestingly, the
electrochemiluminescence (ECL) properties of as-prepared CNNS were
significantly modulated. As a result, unusual changes for different
CNNS in quenching of ECL because of inner filter effect/electron transfer
and enhancement of ECL owing to catalytic effect were observed by
adding different metal ions. On the basis of this, by using various
CNNS, highly selective ECL sensors for rapid detecting multiple metal-ions
such as Cu<sup>2+</sup>, Ni<sup>2+</sup>, and Cd<sup>2+</sup> were
successfully developed without any labeling and masking reagents.
Multiple competitive mechanisms were further revealed to account for
such enhanced selectivity in the proposed ECL sensors. The strategy
of preparing CNNS with tunable chemical structures that facilely modulated
the optical properties would open a vista to explore 2D carbon-rich
materials for developing a wide range of applications such as sensors
with enhanced performances
Vx3-Functionalized Alumina Nanoparticles Assisted Enrichment of Ubiquitinated Proteins from Cancer Cells for Enhanced Cancer Immunotherapy
A simple and effective strategy was
developed to enrich ubiquitinated
proteins (UPs) from cancer cell lysate using the α-Al<sub>2</sub>O<sub>3</sub> nanoparticles covalently linked with ubiquitin binding
protein (Vx3) (denoted as α-Al<sub>2</sub>O<sub>3</sub>–Vx3)
via a chemical linker. The functionalized α-Al<sub>2</sub>O<sub>3</sub>–Vx3 showed long-term stability and high efficiency
for the enrichment of UPs from cancer cell lysates. Flow cytometry
analysis results indicated dendritic cells (DCs) could more effectively
phagocytize the covalently linked α-Al<sub>2</sub>O<sub>3</sub>–Vx3-UPs than the physical mixture of α-Al<sub>2</sub>O<sub>3</sub> and Vx3-UPs (α-Al<sub>2</sub>O<sub>3</sub>/Vx3-UPs).
Laser confocal microscopy images revealed that α-Al<sub>2</sub>O<sub>3</sub>–Vx3-UPs localized within the autophagosome of
DCs, which then cross-presented α-Al<sub>2</sub>O<sub>3</sub>–Vx3-UPs to CD8<sup>+</sup> T cells in an autophagosome-related
cross-presentation pathway. Furthermore, α-Al<sub>2</sub>O<sub>3</sub>–Vx3-UPs enhanced more potent antitumor immune response
and antitumor efficacy than α-Al<sub>2</sub>O<sub>3</sub>/cell
lysate or α-Al<sub>2</sub>O<sub>3</sub>/Vx3-UPs. This work highlights
the potential of using the Vx3 covalently linked α-Al<sub>2</sub>O<sub>3</sub> as a simple and effective platform to enrich UPs from
cancer cells for the development of highly efficient therapeutic cancer
vaccines
Additional file 4:Figure S1. of Small RNA sequencing reveals a role for sugarcane miRNAs and their targets in response to Sporisorium scitamineum infection
Length distribution of the unique sRNA sequences in the four libraries. RCK and YACK: ROC22 and YA05-179 under sterile water stress after 48Â h, respectively; RT and YAT: ROC22 and YA05-179 under Sporisorium scitamineum stress after 48Â h, respectively. (TIF 35Â kb