Abstract
Droplets microfluidics is broadening the range of Lab on a Chip solutions that, however, still suffer from the lack of an adequate level of integration of optical detection and sensors. In ...fact, droplets are currently monitored by imaging techniques, mostly limited by a time-consuming data post-processing and big data storage. This work aims to overcome this weakness, presenting a fully integrated opto-microfluidic platform able to detect, label and characterize droplets without the need for imaging techniques. It consists of optical waveguides arranged in a Mach Zehnder’s configuration and a microfluidic circuit both coupled in the same substrate. As a proof of concept, the work demonstrates the performances of this opto-microfluidic platform in performing a complete and simultaneous sequence labelling and identification of each single droplet, in terms of its optical properties, as well as velocity and lengths. Since the sensor is realized in lithium niobate crystals, which is also highly resistant to chemical attack and biocompatible, the future addition of multifunctional stages into the same substrate can be easily envisioned, extending the range of applicability of the final device.
•Realization of a fully integrated opto-microfluidics platform entirely made on lithium niobate (LiNbO3) crystals for real-time data analysis.•Detection of single droplet passage and estimation of ...its size without the need of any imaging processing.•High quality performances in term of optical triggering, reproducibility and stability in time.•Portable device with increased affordability better than 50% respect standard techniques.
In this work, we realized and tested an integrated opto-microfluidics platform entirely made on lithium niobate (LiNbO3) crystals, able to detect the single droplet passage and estimate its size without the need of any imaging processing. It is based on the coupling of a self-aligned integrated optical stage, made of an array of optical waveguides, to a microfluidic circuit such as a T-junction or Cross-junction engraved in the same substrate. The platform presented high quality performances in terms of optical triggering, reproducibility and stability in time, allowing in real-time data analysis. The comparison with standard approaches using microscopes and fast camera imagining acquisition and relative post-processing, showed an increased capability better than 50%. The demonstrated feasibility of integration of these two stages will allow the realization of a Lab-On-a-Chip on a monolithic substrate of lithium niobate, exploiting its multiple applications for manipulation of droplets.
Keratin (Ker) protein regenerated from readily available and low-cost wastes (e.g. raw wool, feathers and textile by-products) is a promising natural polymer for tissue engineering and drug delivery.
...Nevertheless, while showing good bioactivity and great drug carrier properties, keratin lacks of suitable mechanical characteristics. To overcome this drawback, keratin was blended with poly(butylene succinate) (PBS), a biodegradable and biocompatible polyester able to confer mechanical integrity to the keratin based materials.
Despite the poor compatibility at the molecular level between keratin and PBS, their 50-50 blends were successfully electrospun into manageable mats, made of randomly oriented nanofibers with mean diameter of 290 nm. Along with mechanical properties, PBS improves also the thermal stability of the keratin based nanofibrous mats. On the other hand, compared to PBS-only electrospun mats, the presence of keratin improves both swelling ability and biodegradability and amplifies the capacity of drug release as well as fibroblast proliferation of the blend mat.
•Immiscible Keratin-polybutylene succinate (PBS) solution has been successfully electrospun.•Homogeneous nanofibers of about 290 nm were obtained.•PBS confers mechanical properties and thermal stability to the keratin-based nanofibrous mat.•Keratin confer higher swelling and biodegradability to the keratin-based nanofibrous mat.•Keratin stimulates the fibroblast adhesion and growth.
We report here the preclinical profile of etoricoxib (MK-0663) 5-chloro-2-(6-methylpyridin-3-yl)-3-(4-methylsulfonylphenyl) pyridine, a novel orally active agent that selectively inhibits ...cyclooxygenase-2 (COX-2), that has been developed for high selectivity in vitro using whole blood assays and sensitive COX-1 enzyme assays at low substrate concentration. Etoricoxib selectively inhibited COX-2 in human whole blood assays in vitro, with an IC(50) value of 1.1 +/- 0.1 microM for COX-2 (LPS-induced prostaglandin E2 synthesis), compared with an IC(50) value of 116 +/- 8 microM for COX-1 (serum thromboxane B2 generation after clotting of the blood). Using the ratio of IC(50) values (COX-1/COX-2), the selectivity ratio for the inhibition of COX-2 by etoricoxib in the human whole blood assay was 106, compared with values of 35, 30, 7.6, 7.3, 2.4, and 2.0 for rofecoxib, valdecoxib, celecoxib, nimesulide, etodolac, and meloxicam, respectively. Etoricoxib did not inhibit platelet or human recombinant COX-1 under most assay conditions (IC(50) > 100 microM). In a highly sensitive assay for COX-1 with U937 microsomes where the arachidonic acid concentration was lowered to 0.1 microM, IC(50) values of 12, 2, 0.25, and 0.05 microM were obtained for etoricoxib, rofecoxib, valdecoxib, and celecoxib, respectively. These differences in potency were in agreement with the dissociation constants (K(i)) for binding to COX-1 as estimated from an assay based on the ability of the compounds to delay the time-dependent inhibition by indomethacin. Etoricoxib was a potent inhibitor in models of carrageenan-induced paw edema (ID(50) = 0.64 mg/kg), carrageenan-induced paw hyperalgesia (ID(50) = 0.34 mg/kg), LPS-induced pyresis (ID(50) = 0.88 mg/kg), and adjuvant-induced arthritis (ID(50) = 0.6 mg/kg/day) in rats, without effects on gastrointestinal permeability up to a dose of 200 mg/kg/day for 10 days. In squirrel monkeys, etoricoxib reversed LPS-induced pyresis by 81% within 2 h of administration at a dose of 3 mg/kg and showed no effect in a fecal 51Cr excretion model of gastropathy at 100 mg/kg/day for 5 days, in contrast to lower doses of diclofenac or naproxen. In summary, etoricoxib represents a novel agent that selectively inhibits COX-2 with 106-fold selectivity in human whole blood assays in vitro and with the lowest potency of inhibition of COX-1 compared with other reported selective agents.
The technological quest for flexible devices to be interfaced with the biological world has driven the recent reinvention of bioderived polymers as multifunctional active and passive constituent ...elements for electronic and photonic devices to use in the biomedical field. Keratin is one of the most important structural proteins in nature to be used as biomaterial platform in view of the recently reported advances in the extraction and processing from hair and wool fibers. In this article we report for the first time the simultaneous use of naturally extracted keratin as both active ionic electrolyte for water ions sensing and as bendable and insoluble substrate into the same multielectrode array-based device. We implemented the multifunctional system exclusively made by keratin as a bendable sensor for monitoring the humidity flow.
The enhancement of the functional and structural properties of keratin such as bendability and insolubility were obtained by unprecedented selective chemical doping. The mechanisms at the basis of the sensing of humidity in the device were investigated by cyclic voltammetry and rationalized by reversible binding and extraction of water ions from the volume of the keratin active layer, while the figures of merit of the biopolymer such as the ionic conductivity and relaxation time were determined by means of electrical impedance and dielectric relaxation spectroscopy. A reliable linear correlation between the controlled-humidity level and the amperometric output signal together with the assessment on measure variance are demonstrated. Collectively, the fine-tuned ionic-electrical characterization and the validation in controlled conditions of the free-standing insoluble all-keratin made microelectrode array ionic sensor pave the way for the effective use of keratin biopolymer in wearable or edible electronics where conformability, reliability and biocompatibility are key-enabling features.
•A microelectrode array was fabricated onto a biocompatible and suitable-chemically modified keratin free-standing substrate.•Naturally-extracted keratin was employed as active layer preserving the hygroscopic properties that permit humidity sensing.•Cyclic voltammetry, electrical impedance and dielectric spectroscopy confirm effective material-related sensing properties.
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► We demonstrate how a natural protein, silk-fibroin, can be integrated as an efficient dielectric into organic optoelectronic devices, replacing traditional inorganic oxide layers ...such as SiO
2, plastic PMMA, or other synthetic organic materials. ► We demonstrate how natural silk fibroin can be successfully used as a dielectric material for fabrication of competitive state of the art n- and p-type silk-based organic transistors. ► We demonstrate an advanced silk-based optoelectronic device namely, an unipolar n-type organic light-emitting transistors. ► We demonstrate how biologically based materials, and their technological integration, can enable eco-sustainable manufacturing processes.
We present the integration of a natural protein into electronic and optoelectronic devices by using silk fibroin as a thin film dielectric in an organic thin film field-effect transistor (OFET) ad an organic light emitting transistor device (OLET) structures. Both n- (perylene) and p-type (thiophene) silk-based OFETs are demonstrated. The measured electrical characteristics are in agreement with high-efficiency standard organic transistors, namely charge mobility of the order of 10
−2
cm
2/V
s and on/off ratio of 10
4. The silk-based optoelectronic element is an advanced unipolar n-type OLET that yields a light emission of 100
nW.
This work investigates the preparation of wool keratin sponges by freeze-drying procedure starting form keratin aqueous solutions. The study highlights the correlations between process parameters ...(protein concentration and freezing rate) and the chemical-physical properties of the final sponges.
In particular, as the keratin concentration increases from 1 to 20% wt, the mean pore size and the porosity decrease from 62 to 37μm and from 94 to 50% respectively, while the chemical stability in physiological conditions increases, as well as the thermal stability and the elastic modulus. On the other hand, the increase of the freezing rate affects the design of sponges that appear as stacked leaflets structures with oriented pores.
Moreover, in order to confer to keratin sponges antioxidant properties, polydopamine (PDA) nanoparticles were used as fillers. To this end, PDA nanoparticles of about 130nm were successfully dispersed in the sponges, bestowing time-dependent anti-oxidant properties on the scaffolds, with no significant modification of sponges morphological structure as well as reduction of the thermal stability and mechanical behaviour.
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•Porous keratin sponges were prepared through freeze-drying process starting from aqueous solutions of the protein and in the complete absence of organic solvents•The 3D-scaffolds properties can be controlled by a fine-tuning of the keratin concentration and freezing temperature•The pore size and porosity decreases with increasing the keratin concentration•Elsatic modulus as well as chemical and thermal stability increases with increasing the keratin concentration•Solutions at higher keratin concentration generated sponges with lower pore size and porosity, but higher elastic modulus and higher chemical and thermal stability•Polydopamine nanoparticles/keratin composite sponges displayed a time-dependent antioxidant activity•The tunable keratin based sponges show promising perspectives in tissue-engineering and regenerative medicine.
Isolation, mass production, and characterization in solution and in the solid state of the facial stereoisomer of tris(quinolin‐8‐olato)aluminum(III) (Alq3) is reported. A phase‐ transformation ...diagram shows how to selectively produce the two blue‐emitting polymorphs of the fac isomer (γ‐ and δ‐Alq3; see Figure) via a solid‐to‐solid reaction, opening the route to the development of blue‐light‐emitting Alq3‐based OLEDs.
RESUMO O objetivo deste estudo foi identificar as principais doenças de felinos na região sul do Rio Grande do Sul. Foram revisados os protocolos de necropsia e das amostras biológicas de felinos ...encaminhados ao Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas (LRD/UFPel), no período de 1978 a 2018. Nesse período foram recebidas 1633 amostras de felinos, sendo 363 (22%) entre os anos de 1978 e 1999 e 1270 (78%) entre os anos de 2000 e 2018. Com relação aos diagnósticos, 457 felinos (28%) apresentaram tumores benignos ou malignos, sendo os tegumentares e os mamários os mais frequentes. As doenças bacterianas, fúngicas, virais, parasitárias, sem agente definido e as intoxicações totalizaram 554 casos (33,9%), destacando-se a esporotricose, com 12,8% dos diagnósticos. Concluiu-se que, na região sul do RS, o encaminhamento de felinos para diagnóstico aumentou significativamente após o ano 2000, comprovando que a espécie passou a ter maior importância como animal de companhia. Concluiu-se, também, que as neoplasias têm papel relevante entre as doenças de felinos e que a esporotricose é uma das mais importantes zoonoses na região.
ABSTRACT The goal of this paper was to identify the main disease affecting felines in the southern region of Rio Grande do Sul. The necropsy protocols and feline biological materials submitted to the Regional Diagnostic Laboratory of the Veterinary College of the Federal University of Pelotas (LRD / UFPel) were reviewed, from 1978 to 2018. During this period 1633 feline samples were received, 363 (22%) between 1978 and 1999 and 1270 (78%) between 2000 and 2018. 59% of felines did not present a defined breed. As for diagnoses, 457 felines (28%) presented benign or malignant tumors, the most common being the integumentary and mammary tumors. Bacterial, fungal, viral, parasitic or undefined agent infections and intoxications were observed in 554 cases (33.9%), especially sporotrichosis with 12.8 % of the diagnoses. It was concluded that in southern RS the referral of cats for diagnosis increased significantly after the year 2000, proving that they became more significant as companion animals. It was also concluded that neoplasia play a relevant role among feline diseases, and that sporotrichosis is one of the most important zoonoses in the region.
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