244 research outputs found
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FLIm and raman spectroscopy for investigating biochemical changes of bovine pericardium upon genipin cross-linking
Biomaterials used in tissue engineering and regenerative medicine applications benefit from longitudinal monitoring in a non-destructive manner. Label-free imaging based on fluorescence lifetime imaging (FLIm) and Raman spectroscopy were used to monitor the degree of genipin (GE) cross-linking of antigen-removed bovine pericardium (ARBP) at three incubation time points (0.5, 1.0, and 2.5 h). Fluorescence lifetime decreased and the emission spectrum redshifted compared to that of uncross-linked ARBP. The Raman signature of GE-ARBP was resonance-enhanced due to the GE cross-linker that generated new Raman bands at 1165, 1326, 1350, 1380, 1402, 1470, 1506, 1535, 1574, 1630, 1728, and 1741 cm-1. These were validated through density functional theory calculations as cross-linker-specific bands. A multivariate multiple regression model was developed to enhance the biochemical specificity of FLIm parameters fluorescence intensity ratio (R2 = 0.92) and lifetime (R2 = 0.94)) with Raman spectral results. FLIm and Raman spectroscopy detected biochemical changes occurring in the collagenous tissue during the cross-linking process that were characterized by the formation of a blue pigment which affected the tissue fluorescence and scattering properties. In conclusion, FLIm parameters and Raman spectroscopy were used to monitor the degree of cross-linking non-destructively. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
Optimizing space telescopes’ thermal performance through uncertainty analysis: identification of critical parameters and shaping test strategy development
The integration of uncertainty analysis methodologies allows for improving design efficiency, particularly in the context of instruments that demand precise pointing accuracy, such as space telescopes. Focusing on the VINIS Earth observation telescope developed by the Instituto de Astrofísica de Canarias (IAC), this paper reports an uncertainty analysis on a thermal model aimed at improving cost savings in the future testing phases. The primary objective was to identify critical parameters impacting thermal performance and reduce overdesign. Employing the Statistical Error Analysis (SEA) method across several operational scenarios, the research identifies key factors, including the Earth’s infrared temperature and albedo, and the spacecraft’s attitude and environmental conditions, as the variables with major influences on the system’s thermal performance. Ultimately, the findings suggest that uncertainty-based analysis is a potent tool for guiding thermal control system design in space platforms, promoting efficiency and reliability. This methodology not only provides a framework for optimizing thermal design and testing in space missions but also ensures that instruments like the VINIS telescope maintain optimal operating temperatures in diverse space environments, thereby increasing mission robustness and enabling precise resource allocation.Agencia Estatal de Investigación | Ref. PID2022-141669OA-I00Xunta de GaliciaCabildo de Tenerif
Evaluation of the thermo-elastic response of space telescopes using uncertainty assessment
The aerospace sector is evolving due to reduced launch costs and standardization of small satellite platforms. This research, aligned with European Guidelines for Thermo-Elastic Verification, addresses the pointing precision gap in small satellites by assessing space telescope performance using uncertainty propagation in thermo-elastic models. The methodology will be directly applied to an Earth observation space telescope, VINIS, currently under development by the Instituto de Astrofísica de Canarias (IAC). This procedure helps to identify key design elements impacting its functionality. Thirteen elements were identified as main contributors to the deformations in the optical bench. Due to the bench's crucial role in the telescope's performance, this paper also explores how results vary with different sandwich panel modelling techniques and the enhancements from design modifications. While the focus is on space telescopes, this approach has broader applicability to thermo-elastic analysis of various space instrumentsAgencia Estatal de Investigación | Ref. PID2022-141669OA-I00Xunta de Galicia | Ref. ED481A 2022/107Universidade de Vigo / CISU
Comprehensive analysis of GABAA-A1R developmental alterations in Rett Syndrome: setting the focus for therapeutic targets in the time frame of the disease
Rett syndrome, a serious neurodevelopmental disorder, has been associated with an altered expression of different synaptic-related proteins and aberrant glutamatergic and γ-aminobutyric acid (GABA)ergic neurotransmission. Despite its severity, it lacks a therapeutic option. Through this work we aimed to define the relationship between MeCP2 and GABAA.-A1 receptor expression, emphasizing the time dependence of such relationship. For this, we analyzed the expression of the ionotropic receptor subunit in different MeCP2 gene-dosage and developmental conditions, in cells lines, and in primary cultured neurons, as well as in different developmental stages of a Rett mouse model. Further, RNAseq and systems biology analysis was performed from post-mortem brain biopsies of Rett patients. We observed that the modulation of the MeCP2 expression in cellular models (both Neuro2a (N2A) cells and primary neuronal cultures) revealed a MeCP2 positive effect on the GABAA.-A1 receptor subunit expression, which did not occur in other proteins such as KCC2 (Potassium-chloride channel, member 5). In the Mecp2+/- mouse brain, both the KCC2 and GABA subunits expression were developmentally regulated, with a decreased expression during the pre-symptomatic stage, while the expression was variable in the adult symptomatic mice. Finally, the expression of the gamma-aminobutyric acid (GABA) receptor-related synaptic proteins from the postmortem brain biopsies of two Rett patients was evaluated, specifically revealing the GABA A1R subunit overexpression. The identification of the molecular changes along with the Rett syndrome prodromic stages strongly endorses the importance of time frame when addressing this disease, supporting the need for a neurotransmission-targeted early therapeutic intervention
Physiological and nutritional responses to ozone application in tomato seedling plants
Research on environmentally friendly techniques for the agroindustry is growing constantly. In this sense, the supply of ozone (O3) has been taken into consideration, especially for disinfection because of its high oxidizing power. However, there is not enough information about the application of dissolved O3 via fertigation in crops. For that reason, in this study, two trials were carried out simultaneously to determine the consequences of O3 application on plant growth and quality of tomato plants. The first trial aimed to assess the effects on tomato fertigated with the nutrient solution and the application of O3. The second trial was performed to establish the ideal O3 supply rate for tomato plants. In both experiments, we measured the biometric, physiological, and nutritional parameters of the tomato plant. The results obtained showed that the application of O3 treatment resulted in the highest overall dry weight gain, whereas O3 application decreased leaf proline and total soluble sugars concentrations. There was no clear effect on chlorophyll and total soluble sugars in tomato plants under O3 application. Regarding nutritional parameters, the application of O3 led to a higher content of P and K in tomato plants. These findings indicate that the use of dissolved O3 via fertigation may present several advantages for tomato plants’ growth and quality
A randomized phase II trial of platinum salts in basal-like breast cancer patients in the neoadjuvant setting. Results from the GEICAM/2006-03, multicenter study
Este artículo ha sido publicado en Breast Cancer Research and Treatment
Siguiendo las instruciones y dado que la revista dice que el artículo fue publicado tal cual se envió, hacemos un postprint copiando dicho texto enviado por la revista en un documento Word y luego convertido a PDF para así respetar el contenido, y sin dar acceso a los "extras" de la versión publicada.
Esta versión tiene Licencia Creative Commons CC-BY-NC-NDAbstract Chemotherapy remains as the only systemic treatment option available for basal-like breast cancer (BC) patients. Preclinical models and several phase II studies suggested that platinum salts are active drugs in this BC subtype though there is no randomized study supporting this hypothesis. This study investigates if the addition of carboplatin to a combination of an alkylating agent together with anthracyclines and taxanes is able to increase the efficacy in the neoadjuvant treatment context. Patients with operable breast cancer and immunophenotypically defined basal-like disease (ER-/PR-/HER2- and cytokeratin 5/6?
or EGFR?) were recruited. Patients were randomized to receive EC (epirubicin 90 mg/m2 plus cyclophosphamide
600 mg/m2 for 4 cycles) followed either by D (docetaxel 100 mg/m2 9 4 cycles; EC–D) or DCb (docetaxel 75 mg/
m2 plus carboplatin AUC 6 9 4 cycles; EC–DCb). The primary end point was pathological complete response
(pCR) in the breast following the Miller and Payne criteria. Ninety-four patients were randomized (46 EC–D, 48 EC–
DCb). pCR rate in the breast was seen in 16 patients (35 %) with EC–D and 14 patients (30 %) with EC–DCb
(P value = 0.61). pCR in the breast and axilla was seen in 30 % of patients in both arms. The overall clinical response
rate was 70 % (95 % CI 56–83) in the EC–D arm and 77 % (95 % CI 65–87) in the EC–DCb arm. Grade 3/4 toxicity
was similar in both arms. The addition of carboplatin to conventional chemotherapy with EC–D in basal-like breast
cancer patients did not improve the efficacy probably because they had already received an alkylating agent.
These findings should be taken into consideration when developing new agents for this disease.This trial was partially supported by Pfizer S.L.U
Lack of Annexin A6 exacerbates liver dysfunction and reduces lifespan of Niemann-Pick type C protein-deficient mice
Niemann-Pick type C (NPC) disease is a lysosomal storage disorder characterized by cholesterol accumulation caused by loss-of-function mutations in the Npc1 gene. NPC disease primarily affects the brain, causing neuronal damage and affecting motor coordination. In addition, considerable liver malfunction in NPC disease is common. Recently, we found that the depletion of annexin A6 (ANXA6), which is most abundant in the liver and involved in cholesterol transport, ameliorated cholesterol accumulation in Npc1 mutant cells. To evaluate the potential contribution of ANXA6 in the progression of NPC disease, double-knockout mice (Npc1-/-/Anxa6-/-) were generated and examined for lifespan, eurologic and hepatic functions, as well as liver histology and ultrastructure. Interestingly, lack of ANXA6 in NPC1-deficient animals did not prevent the cerebellar degeneration phenotype, but further deteriorated their compromised hepatic functions and reduced their lifespan. Moreover, livers of Npc1-/-/Anxa6-/- mice contained a significantly elevated number of foam cells congesting the sinusoidal space, a feature commonly associated with inflammation. We hypothesize that ANXA6 deficiency in Npc1-/- mice not only does not reverse neurologic and motor dysfunction, but further worsens overall liver function, exacerbating hepatic failure in NPC disease
Identification of tissue microRNAs predictive of sunitinib activity in patients with metastatic renal cell carcinoma
PURPOSE: To identify tissue microRNAs predictive of sunitinib activity in patients with metastatic renal-cell-carcinoma (MRCC) and to evaluate in vitro their mechanism of action in sunitinib resistance. METHODS: We screened 673 microRNAs using TaqMan Low-density-Arrays (TLDAs) in tumors from MRCC patients with extreme phenotypes of marked efficacy and resistance to sunitinib, selected from an identification cohort (n = 41). The most relevant differentially expressed microRNAs were selected using bioinformatics-based target prediction analysis and quantified by qRT-PCR in tumors from patients presenting similar phenotypes selected from an independent cohort (n = 101). In vitro experiments were conducted to study the role of miR-942 in sunitinib resistance. RESULTS: TLDAs identified 64 microRNAs differentially expressed in the identification cohort. Seven candidates were quantified by qRT-PCR in the independent series. MiR-942 was the most accurate predictor of sunitinib efficacy (p = 0.0074). High expression of miR-942, miR-628-5p, miR-133a, and miR-484 was significantly associated with decreased time to progression and overall survival. These microRNAs were also overexpressed in the sunitinib resistant cell line Caki-2 in comparison with the sensitive cell line. MiR-942 overexpression in Caki-2 up-regulates MMP-9 and VEGF secretion which, in turn, promote HBMEC endothelial migration and sunitinib resistance. CONCLUSIONS: We identified differentially expressed microRNAs in MRCC patients presenting marked sensitivity or resistance to sunitinib. MiR-942 was the best predictor of efficacy. We describe a novel paracrine mechanism through which high miR-942 levels in MRCC cells up-regulates MMP-9 and VEGF secretion to enhance endothelial migration and sunitinib resistance. Our results support further validation of these miRNA in clinical confirmatory studies
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Spaceflight Activates Lipotoxic Pathways in Mouse Liver
Spaceflight affects numerous organ systems in the body, leading to metabolic dysfunction that may have long-term consequences. Microgravity-induced alterations in liver metabolism, particularly with respect to lipids, remain largely unexplored. Here we utilize a novel systems biology approach, combining metabolomics and transcriptomics with advanced Raman microscopy, to investigate altered hepatic lipid metabolism in mice following short duration spaceflight. Mice flown aboard Space Transportation System -135, the last Shuttle mission, lose weight but redistribute lipids, particularly to the liver. Intriguingly, spaceflight mice lose retinol from lipid droplets. Both mRNA and metabolite changes suggest the retinol loss is linked to activation of PPARα-mediated pathways and potentially to hepatic stellate cell activation, both of which may be coincident with increased bile acids and early signs of liver injury. Although the 13-day flight duration is too short for frank fibrosis to develop, the retinol loss plus changes in markers of extracellular matrix remodeling raise the concern that longer duration exposure to the space environment may result in progressive liver damage, increasing the risk for nonalcoholic fatty liver disease
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