Surface Energy and Lewis Acid-base Characteristics of Lignocellulosic Fibers upon Modification by Chemical Vapor Deposition of Trichloromethylsilane: An Inverse Gas Chromatography Study

Supplemental data for this article can be accessed on the publisher’s website at http:// dx.doi.org/10.1080/02773813.2018.1454961The surface of a thermomechanical pulp (TMP), containing 26 wt% of lignin, was modified by silanization with trichloromethylsilane (TCMS) via chemical vapor deposition, and thoroughly analyzed for its physicochemical properties by inverse gas chromatography (attenuated total reflection-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy being used as complementary tools). For a 2-min TCMS-treated TMP, a decrease of the dispersive component of the surface energy from 38 to 14 mJ m−2 (at 40°C), and, at the same time, an increase of the Lewis acidic and Lewis basic characters were found. The surface of this sample, modified in a high extent, was similar to that of a bleached kraft pulp (<0.1 wt% of lignin) subjected to the same silanization process, which is suggested as being due, in both cases, to the formation of a methyl-silica coating on the fiber’s surface. The new silanized fibers obtained from cheap TMP can be used for the production of a new generation of biocomposites with a variety of matrices

Study in COMSOL of the generation of traveling waves in an AEF robot by piezoelectric actuation

[Abstract] This paper presents a study of motion of an artificial eukaryotic flagellum (AEF) microrobot in COMSOL Multiphysics®. The microrobot is essentially a body, consisting of an aluminum beam structure with two piezoelectric patches bonded on its surface. It requires the same voltage with different frequencies or phases be applied to each piezoelectric or use one of the piezoelectrics as absorber in order to generate a traveling wave on the body. Different types of actuation are simulated to demonstrate that a non-reciprocal motion can be obtained with this kind of configuration.[Abstract] Este artículo presenta un estudio del movimiento de un microrobot de eukaryotic flagellum (AEF) en COMSOL Multiphysics®. El microrobot es esencialmente un cuerpo, que consiste en una estructura de vigas de aluminio con dos parches piezoeléctricos adheridos en su superficie. Requiere que se aplique la misma tensión con diferentes frecuencias o fases a cada piezoeléctrico o use uno de los piezoeléctricos como absorbente para generar una onda viajera en el cuerpo. Se simulan diferentes tipos de actuación para demostrar que se puede obtener un movimiento no recíproco con este tipo de configuración.Ministerio de Economía y Competitividad; DPI2016-80547-

Frequency response of IPMC actuators: physical characterization and identification for control

[Abstract] Ionic polymer metal composite (IPMC) actuators have promising applications in robotics and medicine in a not distance future, which will require a big knowledge in different fields, such as, manufacturing, material characterization and control theory. In this paper, frequency response of several IPMC actuators, cut from the same bulk IPMC sheet with a micro laser etching machine, is analyzed. Specifically, the objective is to 1) characterize each actuator, i.e., determine how cutting affects to the parameters of the physical model of this kind of actuators, and 2) identify a model for each actuator for control purposes. The frequency responses have been obtained experimentally in LabVIEW by attaching a couple of gold electrodes to each IPMC unit and measuring the tip deection by means of a laser distance meter.[Resumen] Los actuadores de compuesto de polímero metálico iónico (IPMC) tienen aplicaciones prometedoras en robótica y medicina en un futuro no lejano, lo que requerirá un gran conocimiento en diferentes campos, como la fabricación, la caracterización de materiales y la teoría de control. En este documento, se analiza la respuesta de frecuencia de varios actuadores IPMC, cortados de la misma hoja de IPMC a granel con una máquina de grabado por láser micro. Específicamente, el objetivo es 1) caracterizar cada actuador, es decir, determinar cómo afecta el corte a los parámetros del modelo físico de este tipo de actuadores, y 2) identificar un modelo para cada actuador con fines de control. Las respuestas de frecuencia se han obtenido experimentalmente en LabVIEW al conectar un par de electrodos de oro a cada unidad IPMC y medir la división de la punta por medio de un medidor de distancia láser.Ministerio de Economía y Competitividad; DPI2016-80547-

Hexanucleotide Repeat Expansions in c9FTD/ALS and SCA36 Confer Selective Patterns of Neurodegeneration In Vivo

A G4C2 hexanucleotide repeat expansion in an intron of C9orf72 is the most common cause of frontal temporal dementia and amyotrophic lateral sclerosis (c9FTD/ALS). A remarkably similar intronic TG3C2 repeat expansion is associated with spinocerebellar ataxia 36 (SCA36). Both expansions are widely expressed, form RNA foci, and can undergo repeat-associated non-ATG (RAN) translation to form similar dipeptide repeat proteins (DPRs). Yet, these diseases result in the degeneration of distinct subsets of neurons. We show that the expression of these repeat expansions in mice is sufficient to recapitulate the unique features of each disease, including this selective neuronal vulnerability. Furthermore, only the G4C2 repeat induces the formation of aberrant stress granules and pTDP-43 inclusions. Overall, our results demonstrate that the pathomechanisms responsible for each disease are intrinsic to the individual repeat sequence, highlighting the importance of sequence-specific RNA-mediated toxicity in each disorder

Inhibition of Akt sensitises neuroblastoma cells to gold(III) porphyrin 1a, a novel antitumour drug induced apoptosis and growth inhibition

Background:Gold(III) porphyrin 1a is a new class of anticancer drug, which inhibits cell proliferation of wide range of human cancer cell lines and induces apoptosis in human nasopharyngeal carcinoma cells. However, the underlying signalling mechanism by which gold(III) porphyrin 1a modifies the intracellular apoptosis pathways in tumour cells has not been explained in detail in neuroblastoma cells.Methods:Cell proliferation and apoptosis were determined by measuring 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Annexin V binding, respectively. Western blot assay was used to detect proteins involved in apoptotic and Akt pathways. In vivo tumour growth was assessed by inoculating tumour cells to nude mice subcutaneously, and gold(III) porphyrin 1a was administrated intravenously.Results:This study assessed the antitumour effect and mechanism of gold(III) porphyrin 1a on neuroblastoma in vitro and in vivo. Gold(III) porphyrin 1a displayed a growth inhibition and induction of apoptosis in neuroblastoma cells effectively in vitro, which was accompanied with release of cytochrome c and Smac/DIABLO and caspases activation. Further studies indicated that gold(III) porphyrin 1a inhibited X-linked inhibitor of apoptosis (XIAP). However, we found that gold(III) porphyrin 1a can induce a survival signal, Akt activation within minutes and could last for at least 24 h. To further confirm association between activation of Akt and the effectiveness of gold(III) porphyrin 1a, neuroblastoma cells were treated with API-2, an Akt-specific inhibitor. API-2 sensitised cells to gold(III) porphyrin 1a-induced apoptosis and growth inhibition.Conclusion:These results suggested that Akt may be considered as a molecular brake that neuroblastoma cells rely on to slow down gold(III) porphyrin 1a-induced apoptosis and antiproliferation. Gold(III) porphyrin 1a is a mitochondrial apoptotic stimulus but also activates Akt, suggesting an involvement of Akt in mediating the effectiveness to growth inhibition and apoptosis by gold(III) porphyrin 1a and that inhibition of Akt can enhance the anticancer activity of gold(III) porphyrin 1a in neuroblastoma. © 2009 Cancer Research UK.published_or_final_versio

Hypoxia Inducible Factor 1-Alpha (HIF-1 Alpha) Is Induced during Reperfusion after Renal Ischemia and Is Critical for Proximal Tubule Cell Survival

Acute tubular necrosis (ATN) caused by ischemia/reperfusion (I/R) during renal transplantation delays allograft function. Identification of factors that mediate protection and/or epithelium recovery could help to improve graft outcome. We studied the expression, regulation and role of hypoxia inducible factor 1-alpha (HIF-1 α), using in vitro and in vivo experimental models of I/R as well as human post-transplant renal biopsies. We found that HIF-1 α is stabilized in proximal tubule cells during ischemia and unexpectedly in late reperfusion, when oxygen tension is normal. Both inductions lead to gene expression in vitro and in vivo. In vitro interference of HIF-1 α promoted cell death and in vivo interference exacerbated tissue damage and renal dysfunction. In pos-transplant human biopsies, HIF-1 α was expressed only in proximal tubules which exhibited normal renal structure with a significant negative correlation with ATN grade. In summary, using experimental models and human biopsies, we identified a novel HIF-1 α induction during reperfusion with a potential critical role in renal transplant

Anti-tumour necrosis factor discontinuation in inflammatory bowel disease patients in remission: study protocol of a prospective, multicentre, randomized clinical trial

Background: Patients with inflammatory bowel disease who achieve remission with anti-tumour necrosis factor (anti-TNF) drugs may have treatment withdrawn due to safety concerns and cost considerations, but there is a lack of prospective, controlled data investigating this strategy. The primary study aim is to compare the rates of clinical remission at 1?year in patients who discontinue anti-TNF treatment versus those who continue treatment. Methods: This is an ongoing, prospective, double-blind, multicentre, randomized, placebo-controlled study in patients with Crohn?s disease or ulcerative colitis who have achieved clinical remission for ?6?months with an anti-TNF treatment and an immunosuppressant. Patients are being randomized 1:1 to discontinue anti-TNF therapy or continue therapy. Randomization stratifies patients by the type of inflammatory bowel disease and drug (infliximab versus adalimumab) at study inclusion. The primary endpoint of the study is sustained clinical remission at 1?year. Other endpoints include endoscopic and radiological activity, patient-reported outcomes (quality of life, work productivity), safety and predictive factors for relapse. The required sample size is 194 patients. In addition to the main analysis (discontinuation versus continuation), subanalyses will include stratification by type of inflammatory bowel disease, phenotype and previous treatment. Biological samples will be obtained to identify factors predictive of relapse after treatment withdrawal. Results: Enrolment began in 2016, and the study is expected to end in 2020. Conclusions: This study will contribute prospective, controlled data on outcomes and predictors of relapse in patients with inflammatory bowel disease after withdrawal of anti-TNF agents following achievement of clinical remission. Clinical trial reference number: EudraCT 2015-001410-1

Mechanisms of hypoxic up-regulation of versican gene expression in macrophages

Hypoxia is a hallmark of many pathological tissues. Macrophages accumulate in hypoxic sites and up-regulate a range of hypoxia-inducible genes. The matrix proteoglycan versican has been identified as one such gene, but the mechanisms responsible for hypoxic induction are not fully characterised. Here we investigate the up-regulation of versican by hypoxia in primary human monocyte-derived macrophages (HMDM), and, intriguingly, show that versican mRNA is up-regulated much more highly (&gt;600 fold) by long term hypoxia (5 days) than by 1 day of hypoxia (48 fold). We report that versican mRNA decay rates are not affected by hypoxia, demonstrating that hypoxic induction of versican mRNA is mediated by increased transcription. Deletion analysis of the promoter identified two regions required for high level promoter activity of luciferase reporter constructs in human macrophages. The hypoxia-inducible transcription factor HIF-1 has previously been implicated as a key potential regulator of versican expression in hypoxia, however our data suggest that HIF-1 up-regulation is unlikely to be principally responsible for the high levels of induction observed in HMDM. Treatment of HMDM with two distinct specific inhibitors of Phosphoinositide 3-kinase (PI3K), LY290042 and wortmannin, significantly reduced induction of versican mRNA by hypoxia and provides evidence of a role for PI3K in hypoxic up-regulation of versican expression

Implications of the polymorphism of HLA-G on its function, regulation, evolution and disease association

The HLA-G gene displays several peculiarities that are distinct from those of classical HLA class I genes. The unique structure of the HLA-G molecule permits a restricted peptide presentation and allows the modulation of the cells of the immune system. Although polymorphic sites may potentially influence all biological functions of HLA-G, those present at the promoter and 3′ untranslated regions have been particularly studied in experimental and pathological conditions. The relatively low polymorphism observed in the MHC-G coding region both in humans and apes may represent a strong selective pressure for invariance, whereas, in regulatory regions several lines of evidence support the role of balancing selection. Since HLA-G has immunomodulatory properties, the understanding of gene regulation and the role of polymorphic sites on gene function may permit an individualized approach for the future use of HLA-G for therapeutic purposes