Stochastics theory of log-periodic patterns

We introduce an analytical model based on birth-death clustering processes to help understanding the empirical log-periodic corrections to power-law scaling and the finite-time singularity as reported in several domains including rupture, earthquakes, world population and financial systems. In our stochastics theory log-periodicities are a consequence of transient clusters induced by an entropy-like term that may reflect the amount of cooperative information carried by the state of a large system of different species. The clustering completion rates for the system are assumed to be given by a simple linear death process. The singularity at t_{o} is derived in terms of birth-death clustering coefficients.Comment: LaTeX, 1 ps figure - To appear J. Phys. A: Math & Ge

Genetic background influences murine prostate gene expression: implications for cancer phenotypes

Microarray analyses to quantitate transcript levels in the prostates of five inbred mouse strains identified differences in gene expression in benign epithelium that correlated with the differentiation state of adjacent tumors

Distribuição dos moluscos terrestres da ilha do Pico (Açores) e variabilidade de Oxychilus (Droutia) minor (Morelet, 1860)

XII Expedição Científica do Departamento de Biologia - Pico 2005.Os moluscos terrestres da ilha do Pico têm sido objecto de estudos vários, mas sobre eles de facto pouco se tem publicado. Arthur Morelet, na sua expedição aos Açores em companhia de Henri Drouët, visitou a ilha em 1857 e, em 1860, naquela que foi a primeira grande obra sobre a malacologia açoriana, elencou as espécies encontradas naquela visita. Ali Morelet (1860) descreveu Pupa [= Leiostyla] rugulosa com base num único indivíduo encontrado no Pico, tornando-se esta a primeira espécie endémica de moluscos terrestres adstrita àquela ilha. Se bem que trabalhos posteriores hajam registado esta espécie em outras ilhas (veja Cunha et al., 2005), impõe-se uma revisão deste grupo com base não apenas em caracteres conquiológicos mas sobretudo anatómicos e moleculares no intuito de serem compreendidas as posições taxonómicas e relações filogenéticas destes taxa nas várias ilhas. Para além desta espécie, aquele naturalista francês menciona para o Pico uma variedade â de Limax rufus [Arion lusitanicus], espécie espalhada por outras ilhas açorianas. Morelet (1860) serviu-se ainda das suas observações no Pico para a descrição de outras espécies que reconheceu estarem distribuídas pelas restantes ilhas; tal foi o caso dos ellobiídeos halofílicos Auricula [=Ovatella] vulcani, endemismo açórico, e Auricula bicolor e Auricula vespertina que são consideradas sinónimos de Myosotella myosotis. Para além do que acima foi indicado, apenas mais quatro espécies terrestres mereceram para Morelet menção expressa da ilha do Pico: Helix [= Caracollina] lenticula, uma introdução da Europa então ainda raramente observada nos Açores, Helix [= Heterostoma] paupercula, uma introdução da Madeira igualmente rara, e Bulimus [= Macaronapaeus] forbesianus, um endemismo circunscrito ao Grupo Central. No início do século XX, o barão W. Rothschild realizou uma expedição aos Açores cujas recolhas depositou no Natural History Museum, Londres; entre o material recolhido, mas nunca trabalhado, figuram sete exemplares de Macaronapaeus imaculadamente brancos (BMNH 1903-10-8.175-181), que se crê relacionados com o endemismo terceirense Macaronapaeus alabastrinus, mas cuja decisão aguarda revisão taxonómica apropriada. Nobre (1924) recolheu esta espécie nos arredores do Cais do Pico e menciona-a como Bulimus pruninus mas Backhuys (1975), ciente embora da lista de Nobre, nem se lhe refere; estes autores, porém, se bem que hajam contribuído imensamente para o conhecimento da malacofauna açórica, pouco acrescentaram à lista de Morelet em matéria de novidade endémica para a ilha do Pico

Fetal stem cells obtained from amniotic fluid and wharton's jelly expanded using platelet lysate for tissue engineering applications

Extra-embryonic tissues, such as amniotic fluid (AF) and Wharton´s Jelly (WJ) of umbilical cord, offer many advantages over both embryonic and adult stem cell sources. These tissues are routinely discarded at parturition and the extracorporeal nature of these cell sources facilitates isolation, as well as the comparatively large volume and ease of physical manipulation theoretically increases the number of stem cells that can be isolated. Autologous approaches to use MSCs, namely from bone marrow, have difficulties regarding the limited availability of large amounts of cells from the patient. Fetal stem cells appear to have even more pronounced immunomodulatory properties than adult MSCs (1, 2). This allogeneic escape mechanism may be of therapeutic value, because transplantation of allogeneic human MSCs in stock would be readily available, as opposed to the culture of autologous cells for subsequent transplantation. Cell expansion protocols are based on the use of media supplemented with fetal bovine serum (FBS) as a source of nutrientes and growth factors. The animal serum is not completely safe, once there is a possibility of contamination by animal viroses, prions or others contaminants and it is described that FBS used systematically in MSCs subcultivation induces more humoral immune response (3). Additionally anti-FBS antibodies could be detected in patients after receiving MSCs expanded in FBS (4). Platelet lysate (PL) has enormous possibilities in cell therapy, namely because of the high concentration of growth factors that promotes higher cell expansion, such as tissue regeneration (5). A recent study showed that proliferation of MSCs was much higher on PL gel compared to tissue culture plastic (6). The immunomodulatory properties of MSCs are maintained when expanded in culture medium supplemented with PL (7) Based on these premises we isolated fetal stem cells from AF obtained from amniocentesis and WJ from umbilical cords. These cells were plated and expanded in low density numbers in basal culture medium with FBS or either supplemented with PL. In each passage cells were counted for proliferation kinetics and prepared for flow cytometry analysis. Expanded populations were analysed both population size and complexity and for the MSCs well-known surface markers (CD34, CD45, CD73, CD44, CD106, CD105, CD29, CD90, CD31) and markers related with immune response (HLADR, 80, 83, 86) and embryonic markers SSEA-4 and TRA-1-60

Influência da cultura no bem-estar Materno-Fetal: Uma revisão Narrativa.

Na Gravidez a família é preponderante para o seu sucesso, pois é esta que transmite as suas crenças e costumes, de acordo com a sua cultura, que idealmente proporcionará um parto seguro, com mãe e recém-nascido saudáveis. Com esta revisão narrativa pretendemos conhecer os aspetos culturais que influenciam o comportamento das grávidas. Os artigos foram encontrados nas bases de dados PubMed, CINAHL, MEDLINE, MedicLatina, Nursing & Allied Health Collection, Web of Science e Scielo, através de descritores MeSH, entre 2016 e 2021, que abordassem a influencia dos fatores culturais no comportamento das grávidas. De acordo com a literatura analisada, os aspetos culturais centram-se maioritariamente na alimentação e na espiritualidade, tendendo a culpabilizar a mulher em todas as suas práticas enquanto grávida. Assim, os profissionais de saúde devem estar preparados para as possíveis dificuldades encontradas, devendo estar livres de tabus e preconceitos, para que consigam ajudar as mulheres na sua interação entre a sua cultura e o mundo hospitalar ocidental

P660Molecular insight in apoM-S1P-induced cardioprotection against ischemia/reperfusion injury

Purpose: Apolipoprotein M (apoM) is a plasma lipoprotein that mainly associates with high-density lipoproteins (HDL) and that serves as a carrier of the bioactive lipid Sphingosine-1-Phosphate (S1P). Recent studies indicate that S1P binding to G-protein-coupled receptors, known as S1P-receptors, in the heart activates signalling pathways promoting cardiomyocyte survival, but downstream targets are largely unknown. Here, we investigate the putative role of the apoM-S1P axis in relation to cardioprotection against ischemia/reperfusion (IR) injury. Methods and Results: ApoM transgenic (Apom-Tg) mice, in which plasma S1P is increased by >250%, and wild-type (WT) mice were subjected to 30 min of left coronary artery ligation and 24 hrs reperfusion in vivo. We found a reduction of infarct size in Apom-Tg mice (15±1%) in comparison with WT mice (29±4%, N=8-9, p<0.01). In agreement, neutrophil infiltration into the infarcted area was lower in Apom-Tg mice (14.8±0.2% vs. 25.9±5.1 in WT, N=3, p<0.05). Interestingly, 5 min of S1P treatment at the onset of reperfusion reduced infarct size in response to 30 min of no-flow global ischemia (control: 23±3%, S1P-treated: 11±2%, N=5, p<0.05) in ex vivo Langendorff perfused hearts, suggesting that S1P exerts a direct protective effect on cardiomyocytes. Moreover, the sensitivity to ex vivo IR of Apom-Tg mice was not different from WT mice, further supporting that the cardioprotective effect observed in vivo is due to increased plasmatic S1P in these mice. To obtain further insight into the mechanism underlying S1P-induced cardioprotection, neonatal rat ventricular cardiomyocytes were treated for 5 min with S1P after pre-incubation with PKC kinase inhibitors or with specific antagonists of S1P receptors. We found by Western blot that S1P induced phosphorylation of the gap junction protein Connexin43 (Cx43) on Serine 368 by a PKC-dependent mechanism and that this phosphorylation was mediated by S1P2 and S1P3 but not by S1P1 receptors. Finally, 5 min of S1P treatment reduced gap junctional communication between cardiomyocytes (9±1 cells, N=29) in comparison to control conditions (15±2 cells, N=34, p<0.01), as assessed by dye coupling assay. Conclusion: Increased plasma apoM-S1P in mice protects the heart against IR injury. The molecular mechanism might involve reduced cardiomyocyte death by activation of S1P2 and S1P3 receptors, which leads to PKC-dependent phosphorylation of Cx43 and reduction of cell-to-cell couplin

Performance of PCA3 and TMPRSS2:ERG urinary biomarkers in prediction of biopsy outcome in the Canary Prostate Active Surveillance Study (PASS).

BackgroundFor men on active surveillance for prostate cancer, biomarkers may improve prediction of reclassification to higher grade or volume cancer. This study examined the association of urinary PCA3 and TMPRSS2:ERG (T2:ERG) with biopsy-based reclassification.MethodsUrine was collected at baseline, 6, 12, and 24 months in the multi-institutional Canary Prostate Active Surveillance Study (PASS), and PCA3 and T2:ERG levels were quantitated. Reclassification was an increase in Gleason score or ratio of biopsy cores with cancer to ≥34%. The association of biomarker scores, adjusted for common clinical variables, with short- and long-term reclassification was evaluated. Discriminatory capacity of models with clinical variables alone or with biomarkers was assessed using receiver operating characteristic (ROC) curves and decision curve analysis (DCA).ResultsSeven hundred and eighty-two men contributed 2069 urine specimens. After adjusting for PSA, prostate size, and ratio of biopsy cores with cancer, PCA3 but not T2:ERG was associated with short-term reclassification at the first surveillance biopsy (OR = 1.3; 95% CI 1.0-1.7, p = 0.02). The addition of PCA3 to a model with clinical variables improved area under the curve from 0.743 to 0.753 and increased net benefit minimally. After adjusting for clinical variables, neither marker nor marker kinetics was associated with time to reclassification in subsequent biopsies.ConclusionsPCA3 but not T2:ERG was associated with cancer reclassification in the first surveillance biopsy but has negligible improvement over clinical variables alone in ROC or DCA analyses. Neither marker was associated with reclassification in subsequent biopsies

Specific Glucoside Transporters Influence Septal Structure and Function in the Filamentous, Heterocyst-Forming Cyanobacterium Anabaena sp Strain PCC 7120

T When deprived of combined nitrogen, some filamentous cyanobacteria contain two cell types: vegetative cells that fix CO2 through oxygenic photosynthesis and heterocysts that are specialized in N2 fixation. In the diazotrophic filament, the vegetative cells provide the heterocysts with reduced carbon (mainly in the form of sucrose) and heterocysts provide the vegetative cells with combined nitrogen. Septal junctions traverse peptidoglycan through structures known as nanopores and appear to mediate intercellular molecular transfer that can be traced with fluorescent markers, including the sucrose analog esculin (a coumarin glucoside) that is incorporated into the cells. Uptake of esculin by the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 was inhibited by the -glucosides sucrose and maltose. Analysis of Anabaena mutants identified components of three glucoside transporters that move esculin into the cells: GlsC (Alr4781) and GlsP (All0261) are an ATP-binding subunit and a permease subunit of two different ABC transporters, respectively, and HepP (All1711) is a major facilitator superfamily (MFS) protein that was shown previously to be involved in formation of the heterocyst envelope. Transfer of fluorescent markers (especially calcein) between vegetative cells of Anabaena was impaired by mutation of glucoside transporter genes. GlsP and HepP interact in bacterial two-hybrid assays with the septal junction-related protein SepJ, and GlsC was found to be necessary for the formation of a normal number of septal peptidoglycan nanopores and for normal subcellular localization of SepJ. Therefore, beyond their possible role in nutrient uptake in Anabaena, glucoside transporters influence the structure and function of septal junctions.Peer reviewe

Silk-Fibroin/Methacrylated Gellan Gum Hydrogel as an novel scaffold for application in meniscus cell-based tissue engineering

Introduction: Knee meniscus injury is highly prevalent and there is a demand for new cost-effective treatment solutions. Tissue engineering (TE) and regenerative medicine strategies using acellular scaffolds are being used in clinical application for total or partial meniscus replacement [1]. Although this strategy has been considered as a safe and promising approach, progressive volume reduction of the implant and early failure have been described. Advances in the field of meniscus TE are required and greatly depend on increased knowledge of meniscus biology, improvement of biomaterials and cell-based therapies [2]. Advanced scaffolds for meniscus TE should possess adequate mechanics, biodegradability and biocompatibility, and also be able to mimic and preserve the asymmetric vascular network of this complex tissue, i.e. enable controlling the segmental vascularization during the regeneration process. Silk fibroin scaffolds derived from Bombyx mori cocoon have been recognized as a versatile biomaterial for application in meniscus TE [3]. The purpose of this study is to: 1) contribute to the knowledge of meniscus aiming future clinical applications (namely, the aspects dealing with the characterization of cellular phenotypes and density, biomechanics and extracellular matrix composition) and 2) to develop an alternative and viable silk fibroin scaffold possessing adequate properties for either use in acellular or cellular approaches for partial and/or total meniscus replacement, and combine it with the methacrylated gellan gum hydrogel (iGG-MA) hydrogel, which is able to prevent the ingrowth of endothelial cells and blood vessels into the hydrogels [4,5]. Patients & Methods: Morphologically intact menisci were collected from 44 human donors (12 male, 32 female). All menisci (30 lateral and 14 medial) were divided into anterior, middle and posterior segments prior to mechanical, biological or histological characterization. Human meniscus cells (HMC´s) were isolated using an enzymatic standard protocol. HMC´s phenotype was characterized by flow cytometry analysis. Haematoxylin and eosin (H&E), safranin-O and collagen I staining were performed for segmental characterization of the extracellular matrix. For the evaluation of the viscoelastic properties, dynamic mechanical analysis (DMA) was performed using fresh tissue samples. The three segments of menisci were cut in cylindrical shapes with 4 mm diameter and analyzed at 37ºC in PBS (pH 7.4). The microstructure of freeze-dried meniscus was investigated by micro-computed tomography (micro-CT) analysis. Silk-based scaffolds (10 and 12 wt%) were produced by means of combining salt leaching and freeze-drying methods [3], in order to match human tissue biological and biomechanical features. HMC’s were seeded onto the different silk scaffolds at a cell density of 5x104 cells/disc. Then, the cell-laden scaffolds were cultured in static conditions, for times of culturing up to 21 days. After specific times of culturing (from 1 day up to 21 days), HMC´s adhesion, viability and proliferation were investigated by scanning electron microscopy (SEM), calcein-AM assay and DNA quantification tests, respectively. In addition, the mechanical properties of the cell-loaded scaffolds were evaluated by DMA. The HMC’s-laden hydrogel/silk scaffolds were produced by encapsulating the HMC’s into a 2 wt% iGG-MA hydrogel, followed by impregnation onto the 12 wt% silk scaffold. A chorioallantoic membrane (CAM) assay was used to investigate in vivo the control of segmental vascularization of the acellular and cell-laden hydrogel/silk scaffolds by the effect of iGG-MA hydrogel, until day 14 of embryonic development. Results & Discussion: The biological characterization of this meniscus tissue, although not yet completely accomplished, has evolved significantly in the last few years. In this work, DMA analysis has shown that medial meniscus has significantly higher stiffness (E' and Tan d) than lateral meniscus. There is also significant regional variation form anterior to posterior menisci segments regarding biomechanical features. Age, gender and bone mass index (BMI) also influences meniscus stiffness. The FACS analysis revealed that cells isolated from the human meniscus are a mixed population of cells, i.e. fibrochondrocyte-like and MSCs (cells are positive for CD105, CD73 and CD90, and lack CD34 and CD45). HMC’s maintained their phenotype for 21 days when cultured in tissue culture polystyrene plate (2D). The micro-CT analysis revealed that the human freeze-dried meniscus possessed a mean porosity of 58.0±20.3% and interconectivity of 41.9%±53.7. The mean pore size and trabeculae thickness was 220.7±111.5 µm and 159.7±78.6 µm, respectively. The knowledge arising from the present study allowed us to develop a novel polymeric scaffold made of silk fibroin, which was subsequently characterized without cells and after cell-loading. SEM analysis revealed that the HMC´s adhered to the surface of the scaffolds. The viability assay and DNA quantification showed that HMC´s were viable and proliferated well when cultured onto both silk-10 and silk-12 scaffolds, until 21 days. DMA analysis has shown that the moduli of the acellular scaffolds immersed in culture medium for 14 days were 27.6 ± 7.9 kPa and 61.1 ± 0.4 at 10 Hz, for silk-10 e silk-12, respectively. By its turn, the moduli determined at 10 Hz of the cell-laden scaffolds cultured after 14 days of culturing were 48.2± 19.8 and 140.1 ± 15.6 kPa, for silk-10 and silk-12, respectively. The in vivo study allowed investigating the number of macroscopic blood vessels converging to the implants. The evaluation of possible inflammation and endothelial cells ingrowths was performed by histological (H&E staining) and immunohistochemical methods (SNA-lectin staining). Results have shown that iGG-MA hydrogel prevented the endothelial cells adhesion and blood vessels infiltration into the HMC’s hydrogel/silk scaffolds, after 4 days of implantation, even in the presence of VEGF

Vehicular Storage of Hydrogen in Insulated Pressure Vessels

This paper describes the development of an alternative technology for storing hydrogen fuel onboard automobiles. Insulated pressure vessels are cryogenic-capable pressure vessels that can accept cryogenic liquid fuel, cryogenic compressed gas or compressed gas at ambient temperature. Insulated pressure vessels offer advantages over conventional H{sub 2} storage approaches. Insulated pressure vessels are more compact and require less carbon fiber than GH{sub 2} vessels. They have lower evaporative losses than LH{sub 2} tanks, and are much lighter than metal hydrides. After outlining the advantages of hydrogen fuel and insulated pressure vessels, the paper describes the experimental and analytical work conducted to verify that insulated pressure vessels can be used safely for vehicular H{sub 2} storage. The paper describes tests that have been conducted to evaluate the safety of insulated pressure vessels. Insulated pressure vessels have successfully completed a series of DOT, ISO and SAE certification tests. A draft procedure for insulated pressure vessel certification has been generated to assist in a future commercialization of this technology. An insulated pressure vessel has been installed in a hydrogen fueled truck and it is currently being subjected to extensive testing