1,077 research outputs found
Wettability influences cell behavior on superhydrophobic surfaces with different topographies
Surface wettability and topography are recognized as critical factors influencing cell behavior on biomaterials. So far only few works have reported cell responses on surfaces exhibiting extreme wettability in combination with surface topography. The goal of this work is to study whether cell behavior on superhydrophobic surfaces is influenced by surface topography and polymer type. Biomimetic superhydrophobic rough surfaces of polystyrene and poly(l-lactic acid) with different micro/nanotopographies were obtained from smooth surfaces using a simple phase-separation based method. Total protein was quantified and showed a less adsorption of bovine serum albumin onto rough surfaces as compared to smooth surfaces of the same material. The mouse osteoblastic MC3T3-E1 cell line and primary bovine articular chondrocytes were used to study cell attachment and proliferation. Cells attached and proliferate better in the smooth surfaces. The superhydrophobic surfaces allowed cells to adhere but inhibited their proliferation. This study indicates that surface wettability, rather than polymer type or the topography of the superhydrophobic surfaces, is a critical factor in determining cell behavior
A nationwide overview of 1-year mortality in cardiac arrest patients admitted to intensive care units in the Netherlands between 2010 and 2016
Aim: Worldwide, cardiac arrest (CA) remains a major cause of death. Most post-CA patients are admitted to the intensive care unit (ICU). The aim of this study is to describe mortality rates and possible changes in mortality rates in patients with CA admitted to the ICU in the Netherlands between 2010 and 2016. Methods: In this study, we included all adult CA patients registered in the National Intensive Care Evaluation (NICE) regist
Gold nanoparticles as a part of a photothermal therapy system.
Introduction
Photothermal therapy (PTT) is attracting increased attention for the treatment of superficial localized
tumors, relying on the induction of local hyperthermia of tumor cells upon their irradiation with light
beams1. PTT efficacy depends, however, on the heat generated and, on the depth reached by the light.
Some strategies to improve PTT efficacy includes the use of the near infrared (NIR, 650 to 900 nm)
radiation to enhance the penetration depth of the light, combined with gold nanoparticles (AuNPs) to
enhance the photothermal effect2.
Experimental Methods
Core AuNPs were synthesized by a novel method using tetrachloroauric acid and a mixture of reducing
agents, and subsequently coated with a combination of hyaluronic and oleic acids, for improving the NPs
biocompatibility, biodegradability, and lifetime. This coating also promotes the binding of specific cell
receptors of the tumor cells. The particles were physico-chemically characterized, and in vitro and in vivo
tests were carried out in breast cancer models to assess their safety and efficacy, when applied alone or
combined with NIR irradiation3.
Results and Discussion
AuNPs presented a predominant spherical morphology with sizes under 350 nm, polydispersity index lower
than 0.4 and enhanced absorbance in the NIR. The particles showed no toxicity in vitro and promising
efficacy in vivo when administering the NPs in situ and later irradiating them externally. Histopathological
analysis of tumors treated with both AuNPs and laser irradiation showed the presence of necrosis in most
of the tumors and no effect or practically absence in healthy surrounding cells, which are very encouraging
outcomes.
Conclusion
The results are promising, however, there is still room for improving the system, namely by reducing even
more the invasiveness of the treatment through the combined use of aerogels structures. Aerogel’s unique
properties4 make them ideal candidates to minimize the exposure of healthy tissues to laser radiation,
acting as light and thermal insulators, as well as to incorporate the nanoparticles into their skeletal
structure and thus potentiating a topical application of the particles. For these reasons, some exploratory
methods were carried to produce and design aerogels structures for PTT applications
Serra da Estrela cheeses free amino acids profiles by UPLC-DAD-MS/MS and their application for cheese origin assessment
Serra da Estrela cheese is a high-value Portuguese Protected Designation of Origin cheese, produced with raw ewe milk. Thus, information regarding its composition is of utmost relevance for both consumers and certified producers. In this work, the chromatographic profiles of free amino acids in cheeses (45 days of maturation, 6 producers located in 5 municipalities and produced from November 2017 to March 2018) were established by UPLC-DAD-MS/MS. The proposed method allowed detecting 19 free amino acids and cystine with overall limits of detection and quantification lower than 44 mol/L (1.4 mg/100 g cheese, wet matter) and then 134 mol/L (4.2 mg/100 g cheese, wet matter), respectively. In all cheeses, 17 free amino acids were quantified including 8 essential amino acids (histidine, leucine-isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine) and 9 non-essential amino acids (arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, proline, serine and tyrosine). The amounts of the free amino acids, essential free amino acids, branched chain free amino acids (leucine, isoleucine and valine) plus the free amino acids ratios (mg/g protein) were further used to identify the producer of Serra da Estrela cheeses. Linear discriminant analysis coupled with the simulated annealing variable selection algorithm was used allowing the correct classification of 96% and 90±8% of the samples, for leave-one-out and repeated K-fold cross-validation procedures, respectively. The satisfactory predictive performance pointed out the possibility of using cheeses amino acids profiles as origin biomarkers for authenticity control, warranting the correctness identification of the cheese producer/brand, which is quite relevant for ensuring the consumer confidence and satisfaction when purchasing this high-value dairy food.This work was financially supported by Associate Laboratory LSRELCM – UID/EQU/50020/2019, strategic funding UID/BIO/04469/2019-CEB and BioTecNorte operation (NORTE-01-0145-FEDER000004), and strategic project PEst-OE/AGR/UI0690/2014–CIMO funded by – funded by national funds through FCT/MCTES (PIDDAC). The authors would also like to acknowledge the funding provided by the approved Project, with reference 02/SAICT/ 2016/23290, entitled Characterization and Valorization of QSE PDO and its ability for health promotion (QCLASSE), financed by FCT. S. I. Falcão thanks National funding by FCT- Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio
Governing processes for reactive nitrogen compounds in the atmosphere in relation to ecosystem climatic and human health impacts
Reactive nitrogen (Nr) compounds have different fates in the atmosphere due to differences in governing processes of physical transport, deposition and chemical transformation. Nr compounds addressed here include reduced nitrogen (NHx: ammonia (NH3) and its reaction product ammonium (NH4+)), oxidized nitrogen (NOy: nitrogen monoxide (NO) + nitrogen dioxide (NO2) and their reaction products) as well as organic nitrogen compounds (organic N). Pollution abatement strategies need to take into account these differences in the governing processes of these compounds when assessing their impact on ecosystem services, biodiversity, human health and climate. NOx (NO + NO2) emitted from traffic affects human health in urban areas where the presence of buildings increases the residence time in streets. In urban areas this leads to enhanced exposure of the population to NOx concentrations. NOx emissions have little impact on nearby ecosystems because of the small dry deposition rates of NOx. These compounds need to be converted into nitric acid (HNO3) before removal through deposition is efficient. HNO3 sticks quickly to any surface and is thereby either dry deposited or incorporated into aerosols as nitrate (NO3−). In contrast to NOx compounds, NH3 has potentially high impacts on ecosystems near the main agricultural sources of NH3 because of its large ground-level concentrations along with large dry deposition rates. Aerosol phase NH4+ and NO3− contribute significantly to background PM2.5 and PM10 (mass of aerosols with a diameter of less than 2.5 and 10 μm, respectively) with an impact on radiation balance as well as potentially on human health. Little is known quantitatively and qualitatively about organic N in the atmosphere, other than that it contributes a significant fraction of wet-deposited N, and is present in both gaseous and particulate forms in the atmosphere. Further studies are needed to characterize the sources, air chemistry and removal rates of organic N emissions
Orthographic depth and its impact on Universal Predictors of Reading: a cross-language investigation
Alphabetic orthographies differ in the transparency of their letter-sound mappings, with English orthography being less
transparent than other alphabetic scripts. The outlier status of English has led scientists to question the generality of findings
based on English-language studies. We investigated the role of phonological awareness, memory, vocabulary, rapid naming, and
nonverbal intelligence in reading performance across five languages lying at differing positions along a transparency continuum
(Finnish, Hungarian, Dutch, Portuguese, and French). Results from a sample of 1,265 children in Grade 2 showed that phonological
awareness was the main factor associated with reading performance in each language. However, its impact was modulated by
the transparency of the orthography, being stronger in less transparent orthographies. The influence of rapid naming was rather
weak and limited to reading and decoding speed. Most predictors of reading performance were relatively universal across these
alphabetic languages, although their precise weight varied systematically as a function of script transparenc
Photoacoustic Spectroscopy For Depth-profile Analysis And Herbicide Monitoring In Leaves
Depth profiles of double-layer biological samples obtained by photoacoustic spectroscopy were studied using the two-signal phase-resolved method. The application of the method was demonstrated by singling out the spectra of the cuticle and the pigment layers of a leaf, and the pericarps and the endosperm layers of a corn kernel. The use of the method for monitoring temporal changes occurring in a leaf under the action of a herbicide was also investigated.112111487149
Effect of recombinant human erythropoietin in a rat model of moderate chronic renal failure – focus on inflammation, oxidative Stress and function/renoprotection
Background/Aims: Chronic renal failure (CRF) patients develop anaemia, thus promoting cardiovascular complications, which seems to be favoured by the low kidney erythropoietin (EPO) production. The renal insufficiency
degree might determine the moment to start recombinant human EPO (rhEPO) therapy. It has been attributed important
non-hematopoietic effects to rhEPO, which might underlie cardio and renoprotection. This work aimed to evaluate the effect of rhEPO in a rat model of moderate CRF, focusing on inflammation, oxidative stress and function/renoprotection.
Methods: Four groups (n=7) of male Wistar rats were evaluated during a 15 week follow-up period: control (without
treatment); rhEPO (50 IU/Kg/wk Recormon®); CRF and CRF+rhEPO. Blood samples were collected at the beginning and
3, 9 and 12 weeks after 3/4 nephrectomy, in order to evaluate: renal function, haematological parameters, iron metabolism
and serum proliferative (TGF-B1), inflammatory (TNF-a, CRP, IL-2 and IL-1B) and redox status (MDA, TAS and 3-NT)
markers. Kidney gene expression of Il2, Vegf, Nos2 and Nos3 were assessed by real-time PCR. Blood pressure, heart rate
and tissues trophy indexes were also estimated.
Results: Our data are consistent with a sustained moderate degree of CRF with development of moderate and corrected
anaemia and hypertension. The remnant kidney showed a proliferative profile, with increased mass (hypertrophism),
upregulated tissue Vegf gene expression, accompanied by increased levels of serum TGF-B1. Serum 3-NT was augmented, suggesting oxidative stress, which was accompanied by a trend to higher kidney Nos gene expression of both isoforms. rhEPO treatment was able to partially attenuate renal function markers, totally correct anaemia, also
demonstrating a proliferative and antioxidant action, suggesting renoprotection.
Conclusion: This study suggests that rhEPO therapy might be recommended in moderate CRF stages in order to efficiently correct not only the anaemia but also the underlying deleterious mechanisms, due to a proliferative and antioxidant action on the remnant kidney.info:eu-repo/semantics/publishedVersio
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