214 research outputs found
Structural and Electrical Investigation of Cobalt-Doped NiOx/Perovskite Interface for Efficient Inverted Solar Cells
Inorganic hole-transporting materials (HTMs) for stable and cheap inverted
perovskite-based solar cells are highly desired. In this context, NiOx, with low synthesis temperature,
has been employed. However, the low conductivity and the large number of defects limit the boost
of the efficiency. An approach to improve the conductivity is metal doping. In this work, we have
synthesized cobalt-doped NiOx nanoparticles containing 0.75, 1, 1.25, 2.5, and 5 mol% cobalt (Co) ions
to be used for the inverted planar perovskite solar cells. The best efficiency of the devices utilizing the
low temperature-deposited Co-doped NiOx HTM obtained a champion photoconversion efficiency
of 16.42%, with 0.75 mol% of doping. Interestingly, we demonstrated that the improvement is not
from an increase of the conductivity of the NiOx film, but due to the improvement of the perovskite
layer morphology. We observe that the Co-doping raises the interfacial recombination of the device
but more importantly improves the perovskite morphology, enlarging grain size and reducing the
density of bulk defects and the bulk recombination. In the case of 0.75 mol% of doping, the beneficial
effects do not just compensate for the deleterious one but increase performance further. Therefore,
0.75 mol% Co doping results in a significant improvement in the performance of NiOx-based inverted
planar perovskite solar cells, and represents a good compromise to synthesize, and deposit, the
inorganic material at low temperature, without losing the performance, due to the strong impact
on the structural properties of the perovskite. This work highlights the importance of the interface
from two different points of view, electrical and structural, recognizing the role of a low doping Co
concentration, as a key to improve the inverted perovskite-based solar cells’ performance
Up-Converting Lanthanide-Doped YAG Nanospheres
The development of lanthanide-doped Y3Al5O12 (Ln:YAG) garnet nanostructures is
a hot topic in the field of inorganic nanophosphors due to the current interest
in developing small nanoparticles for solid-state lighting (SSL), displays, lasers and
scintillation applications. In this study, we report the preparation of homogeneous
Ln:YAG (Ln: Ho/Yb ions) nanospheres through a combined two-steps coprecipitationsolvothermal synthesis at low temperature. The crystal growth takes place in ethylene
glycol, which is an inexpensive, non-toxic and easily available solvent. Monodisperse
and crystalline spherical YAG particles of 80 nm in diameter were obtained. Furthermore,
the protocol can be extended to other compositions (Tb/Yb, Tm/Yb. . .) to explore
different luminescent properties, without affecting the morphology of the material,
indicating the robustness and practical utility of the reported methodology. Thermal
treatment of the nanogarnets at 1200◦C is necessary for making materials optically
active upon both UV and NIR excitation. The spherical morphology of annealed samples
is preserved, what helps their further dispersion in solvents, barbotines, inks or printing
vehicles. The lanthanide-doped nanogarnets exhibited the characteristic blue, green
and red emissions from lanthanide upconversion photoluminescence (UCPL) upon NIR
excitation. The UCPL mechanism was studied and CIE chromate coordinates were
obtained. These nanogarnets were further evaluated as functional ceramic phosphors
by incorporating them into commercial glazes. The materials exhibited an exceptional
chemical stability in a harsh medium such as a fused glaze. Consequently, the visible
emissions of the nanoparticles were transferred to the whole glass matrix, thus providing
a functional glaze that emits intense blue and green light upon NIR excitation. These
luminescent nanogarnets have promising applications in smart enamels, but can
also be useful for lighting displays (white LEDs. . .), smart paintings or plastics, and
anti-counterfeiting systems
Glutathione reductase directly mediates the stimulation of yeast glucose-6-phosphate dehydrogenase by GSSG
Hepatic proteome changes in solea senegalensis exposed to contaminated estuarine sediments: a laboratory and in situ survey
Assessing toxicity of contaminated estuarine
sediments poses a challenge to ecotoxicologists due to the
complex geochemical nature of sediments and to the
combination of multiple classes of toxicants. Juvenile
Senegalese soles were exposed for 14 days in the laboratory and in situ (field) to sediments from three sites (a
reference plus two contaminated) of a Portuguese estuary.
Sediment characterization confirmed the combination of
metals, polycyclic aromatic hydrocarbons and organochlorines in the two contaminated sediments. Changes in liver
cytosolic protein regulation patterns were determined by a
combination of two-dimensional electrophoresis with de
novo sequencing by tandem mass spectrometry. From the
forty-one cytosolic proteins found to be deregulated, nineteen were able to be identified, taking part in multiple
cellular processes such as anti-oxidative defence, energy
production, proteolysis and contaminant catabolism (especially oxidoreductase enzymes). Besides a clear distinction
between animals exposed to the reference and contaminated sediments, differences were also observed between
laboratory- and in situ-tested fish. Soles exposed in the
laboratory to the contaminated sediments failed to induce,
or even markedly down-regulated, many proteins, with the
exception of a peroxiredoxin (an anti-oxidant enzyme) and
a few others, when compared to reference fish. In situ
exposure to the contaminated sediments revealed significant up-regulation of basal metabolism-related enzymes,
comparatively to the reference condition. Down-regulation
of basal metabolism enzymes, related to energy production
and gene transcription, in fish exposed in the laboratory to
the contaminated sediments, may be linked to sedimentbound contaminants and likely compromised the organisms’ ability to deploy adequate responses against insult.info:eu-repo/semantics/publishedVersio
Switchable All Inorganic Halide Perovskite Nanocrystalline Photoelectrodes for Solar-Driven Organic Transformations
All inorganic halide perovskite nanocrystals (NCs) are considered as fascinating
materials for a wide range of optoelectronic applications encompassing photovoltaics,
lasing, sensing, and photocatalysis due to their outstanding optoelectronic
properties. Herein, it is demonstrated that the photoelectrochemical
behavior of CsPbBr3 NC films can be tailored through engineering the selective
contacts and accepting species in the electrolyte. This concept has been successfully
applied to the photoelectrochemical oxidation of benzyl alcohol (BzOH)
to benzyl aldehyde (BzCHO) and the reverse photoelectrochemical reduction of
BzCHO to BzOH, demonstrating that CsPbBr3 NCs activate both reactions with
photocurrents up to 40 μA cm 2 toward BzCHO production and 5 μA cm 2 for
the reverse reaction at 0.15 V versus normal hydrogen electrode. The obtained
results highlight the huge potential and versatility of halide perovskite NCs for
photoelectrocatalytic applications, validating the implementation of these
materials for a wide range of solar-driven complex organic transformations, and
emphasizing the urgent need for stabilization strategies to move beyond the
proof-of-concept stage to relevant technological developments
Trazodone for the treatment of fibromyalgia: an open-label, 12-week study
Background:
Despite its frequent use as a hypnotic, trazodone has not been systematically assessed in fibromyalgia patients. In the present study have we evaluated the potential effectiveness and tolerability of trazodone in the treatment of fibromyalgia.
Methods:
A flexible dose of trazodone (50-300 mg/day), was administered to 66 fibromyalgia patients for 12 weeks. The primary outcome measure was the Pittsburgh Sleep Quality Index (PSQI). Secondary outcome measures included the Fibromyalgia Impact Questionnaire (FIQ), the Beck Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS), the Brief Pain Inventory (BPI), the Short-Form Health Survey (SF-36), and the Patients' Global Improvement Scale (PGI). Trazodone's emergent adverse reactions were recorded. Data were analyzed with repeated measures one-way ANOVA and paired Student's t test.
Results:
Trazodone markedly improved sleep quality, with large effect sizes in total PSQI score as well on sleep quality, sleep duration and sleep efficiency. Significant improvement, although with moderate effect sizes, were also observed in total FIQ scores, anxiety and depression scores (both HADS and BDI), and pain interference with daily activities. Unexpectedly, the most frequent and severe side effect associated with trazodone in our sample was tachycardia, which was reported by 14 (21.2%) patients.
Conclusions:
In doses higher than those usually prescribed as hypnotic, the utility of trazodone in fibromyalgia management surpasses its hypnotic activity. However, the emergence of tachycardia should be closely monitored.
Trial registration:
This trial has been registered with ClinicalTrials.gov number NCT-00791739
Trazodone plus pregabalin combination in the treatment of fibromyalgia: a two-phase, 24-week, open-label uncontrolled study
<p>Abstract</p> <p>Background</p> <p>Although trazodone is frequently used by fibromyalgia patients, its efficacy on this disease has not been adequately studied. If effective, pregabalin, whose beneficial effects on pain and sleep quality in fibromyalgia have been demonstrated, could complement the antidepressant and anxiolytic effects of trazodone. The aim of the present study was to assess the effectiveness of trazodone alone and in combination with pregabalin in the treatment of fibromyalgia.</p> <p>Methods</p> <p>This was an open-label uncontrolled study. Trazodone, flexibly dosed (50-300 mg/day), was administered to 66 fibromyalgia patients during 12 weeks; 41 patients who completed the treatment accepted to receive pregabalin, also flexibly dosed (75-450 mg/day), added to trazodone treatment for an additional 12-week period. Outcome measures included the Fibromyalgia Impact Questionnaire (FIQ), the Pittsburgh Sleep Quality Index (PSQI), the Beck Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS), the Brief Pain Inventory (BPI), the Short-Form Health Survey (SF-36), and the Patients' Global Improvement scale (PGI). Emergent adverse reactions were recorded. Data were analyzed with repeated measures one-way ANOVA and paired Student's t test.</p> <p>Results</p> <p>Treatment with trazodone significantly improved global fibromyalgia severity, sleep quality, and depression, as well as pain interference with daily activities although without showing a direct effect on bodily pain. After pregabalin combination additional and significant improvements were seen on fibromyalgia severity, depression and pain interference with daily activities, and a decrease in bodily pain was also apparent. During the second phase of the study, only two patients dropped out due to side effects.</p> <p>Conclusions</p> <p>Trazodone significantly improved fibromyalgia severity and associated symptomatology. Its combination with pregabalin potentiated this improvement and the tolerability of the drugs in association was good.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00791739">NCT00791739</a></p
- …