Titanium is one of the most abundant elements in the earth’s crust and while there are many examples of its bioactive properties and use by living organisms, there are few studies that have probed ...its biochemical reactivity in physiological environments. In the cosmetic industry, TiO2 nanoparticles are widely used. They are often incorporated in sunscreens as inorganic physical sun blockers, taking advantage of their semiconducting property, which facilitates absorbing ultraviolet (UV) radiation. Sunscreens are formulated to protect human skin from the redox activity of the TiO2 nanoparticles (NPs) and are mass-marketed as safe for people and the environment. By closely examining the biological use of TiO2 and the influence of biomolecules on its stability and solubility, we reassess the reactivity of the material in the presence and absence of UV energy. We also consider the alarming impact that TiO2 NP seepage into bodies of water can cause to the environment and aquatic life, and the effect that it can have on human skin and health, in general, especially if it penetrates into the human body and the bloodstream.
We report the fabrication of polyaniline nanofiber (PANI)-modified screen-printed electrode (PANI/SPE) incorporated in a poly-dimethylsiloxane (PDMS) microfluidic channel for the detection of ...circulating tumor cells. We employed this device to detect melanoma skin cancer cells through specific immunogenic binding of cell surface biomarker melanocortin 1 receptor (MC1R) to anti-MC1R antibody. The antibody-functionalized PANI/SPE was used in batch-continuous flow-through fashion. An aqueous cell suspension of ferri/ferrocyanide at a flow rate of 1.5 mL/min was passed over the immunosensor, which allowed for continuous electrochemical measurements. The sensor performed exceptionally well affording an ultralow limit of quantification of 1 melanoma cell/mL, both in buffer and when mixed with peripheral blood mononuclear cells, and the response was log-linear over the range of 10–9000 melanoma cells/10 mL.
•A microfluidics-based immunoelectrochemical sensor was developed.•An ultralow limit of quantification of 1 cell/mL was achieved.•The sensor performance was verified via cell culture experiments.•The sensor response is stable, repeatable, and linear over a wide range.•This system is potentially useful for rapid detection of circulating tumor cells.
Flexible fibre supercapacitors were fabricated by wet-spinning from carbon nanotube/carbon black dispersions, followed by straightforward surface treatments to sequentially deposit MnO2 and PEDOT:PSS ...to make ternary composite fibres. Dip coating the fibres after the initial wet-spinning coagulation creates a simple solution-based continuous process to produce fibre-based energy storage. Well-controlled depositions were achieved and have been optimised at each stage to yield the highest specific capacitance. A single ternary composite fibre exhibited a specific capacitance of 351 F g−1. Two ternary composite fibre electrodes were assembled together in a parallel solid-state device, with polyvinyl alcohol/H3PO4 gel used as both an electrolyte and a separator. The assembled flexible device exhibited a high specific capacitance of 51.3 F g−1 with excellent both charge-discharge cycling (84.2% capacitance retention after 1000 cycles) and deformation cycling stability (82.1% capacitance retention after 1000 bending cycles).
Display omitted
•Carbon-MnO2-PEDOT:PSS composite fibres have been prepared by all aqueous solution based depositions.•Ternary composite fibres show fexibility and excellent energy storage capacity.•Ternary fibres are assembled in solid-state supercapacitors with good capacitive performance for wearable electronics.
Display omitted
Cellulose fibers from “Banana Tabasco” plant rachis, were isolated using a combination of soft chemical treatments, and were mechanically comminuted with a high energy ball mill at ...different milling timings.
Infrared spectroscopy (FTIR-ATR) and nuclear magnetic resonance (1H NMR) were used to study the effects of grinding on the molecular structure and depolymerization of the comminuted cellulose. Changes in morphology, crystallinity index, particle size, thermal properties, and solubility, were also studied using different characterization techniques. Previously reported catalyst (Al2O3-TiO2-W with 5 wt% of W) which was successfully probed in the production of hydroxymethylfurfural (5-HMF) from glucose, was employed for the transformation of the comminuted cellulose into 5-HMF. The reactivity of the Al2O3-TiO2-W catalyst in the conversion of cellulose into 5-HMF, was successful for all comminuted cellulose samples; whereas for commercial cellulose, the catalyst did not work, possibly due to the high polymerization degree. For most of the samples the highest 5-HMF concentration obtained was between 43 and 50 mg/mL at 60 min of reaction. At 120 min, the sample comminuted for 1.5 h grinding showed the highest 5-HMF concentration of 46 mg/mL; this result was associated to the transformation of cellulose oligomers with the most appropriate chain size. The cellulose extracted from Tabasco Banana rachis by means of the methodology established in this study, presented favorable features for the conversion into 5-HMF.
Magnetic nanorods driven by rotating fields in water can be rapidly steered along any direction while generating strong and localized hydrodynamic flow fields. Here we show that, when raising the ...frequency of the rotating field, these nanopropellers undergo a dynamic transition from a rolling to a kayak-like motion due to the increase in viscous drag and acquire a finite inclination angle with respect to the plane perpendicular to the bottom surface. We explain these experimental observations with a theoretical model which considers the nanorod as a pair of ferromagnetic particles hydrodynamically interacting with a close stationary surface. Further, we quantify how efficiently microscopic cargoes can be trapped or expelled from the moving nanorod and use numerical simulations to unveil the generated hydrodynamic flow field. These propulsion regimes can be implemented in microfluidic devices to perform precise operations based on the selective sorting of microscopic cargoes.
Summary
Plant hydraulics is crucial for assessing the plants' capacity to extract and transport water from the soil up to their aerial organs. Along with their capacity to exchange water between ...plant compartments and regulate evaporation, hydraulic properties determine plant water relations, water status and susceptibility to pathogen attacks. Consequently, any variation in the hydraulic characteristics of plants is likely to significantly impact various mechanisms and processes related to plant growth, survival and production, as well as the risk of biotic attacks and forest fire behaviour. However, the integration of hydraulic traits into disciplines such as plant pathology, entomology, fire ecology or agriculture can be significantly improved. This review examines how plant hydraulics can provide new insights into our understanding of these processes, including modelling processes of vegetation dynamics, illuminating numerous perspectives for assessing the consequences of climate change on forest and agronomic systems, and addressing unanswered questions across multiple areas of knowledge.
Increasing temperature and drought can result in leaf dehydration and defoliation even in drought‐adapted tree species such as the Mediterranean evergreen Quercus ilex L. The stomatal regulation of ...leaf water potential plays a central role in avoiding this phenomenon and is constrained by a suite of leaf traits including hydraulic conductance and vulnerability, hydraulic capacitance, minimum conductance to water vapour, osmotic potential and cell wall elasticity. We investigated whether the plasticity in these traits may improve leaf tolerance to drought in two long‐term rainfall exclusion experiments in Mediterranean forests. Osmotic adjustment was observed to lower the water potential at turgor loss in the rainfall‐exclusion treatments, thus suggesting a stomatal closure at more negative water potentials and a more anisohydric behaviour in drier conditions. Conversely, leaf hydraulic conductance and vulnerability did not exhibit any plasticity between treatments so the hydraulic safety margins were narrower in the rainfall‐exclusion treatments. The sequence of leaf responses to seasonal drought and dehydration was conserved among treatments and sites but trees were more likely to suffer losses of turgor and hydraulic functioning in the rainfall‐exclusion treatments. We conclude that leaf plasticity might help the trees to tolerate moderate drought but not to resist severe water stress.
A recent survey of the European Academy of Allergy and Clinical Immunology (EAACI) Drug Allergy Interest Group (DAIG) on how European allergy specialists deal with beta‐lactam (BL) hypersensitivity ...demonstrated a significant heterogeneity in current practice, suggesting the need to review and update existing EAACI guidelines in order to make the diagnostic procedures as safe and accurate, but also as cost‐effective, as possible. For this purpose, a bibliographic search on large studies regarding BL hypersensitivity diagnosis was performed by an EAACI task force, which reviewed and evaluated the literature data using the GRADE system for quality of evidence and strength of recommendation. The updated guidelines provide a risk stratification in BL hypersensitivity according to index reaction(s), as well as an algorithmic approach, based on cross‐reactivity studies, in patients with a suspicion of BL hypersensitivity and an immediate need for antibiotic therapy, when referral to an allergist is not feasible. Furthermore, the update addresses availability and concentrations of skin test (ST) reagents, ST and drug provocation test (DPT) protocols, and diagnostic algorithms and administration of alternative BL in allergic subjects. Specifically, distinct diagnostic algorithms are suggested depending on risk stratification of the patient into high and low risk based on the morphology and chronology of the reaction, immediate (ie, occurring within 1‐6 hours after the last administered dose) or nonimmediate (ie, occurring more than 1 hour after the initial drug administration), and the reaction severity. Regarding the allergy workup, the main novelty of this document is the fact that in some low‐risk nonimmediate reactions ST are not mandatory, especially in children. For DPT, further studies are necessary to provide data supporting the standardization of protocols, especially of those regarding nonimmediate reactions, for which there is currently no consensus.
Purpose
Myopia has emerged as a significant public health concern. Effective methods have now been developed to delay its onset and progression. However, this information may not be reaching parents, ...and they are key players in terms of implementing the necessary preventive measures. This study investigated parental awareness of myopia, its implications and the strategies available for controlling it.
Methods
A self‐administered online survey was distributed to parents of children 6–16 years of age. To be eligible to respond, their child had to be myopic or at risk of developing myopia due to family history.
Results
A total of 330 parents completed the survey, of which 321 were included for analysis. Sixty‐seven percent of respondents had at least one myopic son/daughter, and most were between −1.00 and −1.75 D. Among parents of myopic children, 20.9% thought that their child's myopia progressed moderately. Sixty‐seven percent of parents had a significant level of concern about the progression of the myopia and felt that it was caused mainly by the use of electronic devices and genetics. A generalised linear model showed that parental concern was significantly predicted by the perception of evolution (p < 0.001) and the number of known health‐related consequences (p < 0.001). Almost 40% of parents were unaware of the existence of myopia control strategies. Relatives and eye care practitioners are the main sources of information. The most well‐known myopia control strategy was myopia control soft contact lenses (29.2%), although the option that most parents would opt for was spectacles with peripheral defocus lenses (47.1%). The selection of a contact‐lens‐based myopia control method correlated significantly with the age of the children (p < 0.001).
Conclusions
Society in general and parents in particular need more information about myopia, its consequences and the options available for its control. Eye care practitioners play an important role in this issue.
Conducting polymers (CPs) play a vital role in imparting electrochemical and photothermal properties to thermosensitive conducting hydrogels (TCH). The application of TCH is expanding not only for ...biomedical applications but also to address water scarcity. While the volume phase transition (VPT) phenomenon in thermosensitive polymers has been extensively studied, the contribution of CPs to this process and the underlying chemical interactions remain unclear and low explored. In this study, we present a novel conducting polymer hydrogel (CPH) utilizing the thermosensitive polymer poly(N-isopropylacrylamide) (PNIPAAm) enriched with poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles as a model system. This serves as a platform for both experimental and theoretical investigations into the influence of CPs on VPT. Through a comprehensive examination of hydrogel responses to temperature employing Raman spectroscopy, atomistic simulations using advanced hybrid methodologies, and artificial intelligence, we unveil a shielding effect of CP. This effect arises from robust chemical interactions with NIPAAm, inducing a selective dehydration of the hydrogel microenvironment. Remarkably, this mirrors the phenomenon observed during VPT triggered by an increase in the hydrogel temperature. Understanding the intricate interactions between conducting and thermosensitive polymers is imperative for the systematic development and fine-tuning of the performance of future CPHs. This knowledge ensures a more precise adaptation of these materials to their intended end applications.
PDF
