Control no lineal del sistema Twin Rotor

El Twin Rotor MIMO System és un sistema mecànic amb múltiples entrades i múltiples sortides assimilable a un helicòpter, però d’escala més reduïda. Una diferència destacable entre el Twin Rotor MIMO System i una maqueta d’helicòpter és que les forces aerodinàmiques no varien segons l’angle d’atac de les pales de les hèlixs sinó segons la velocitat angular dels rotors de les hèlixs. Les equacions diferencials que modelen el sistema són no lineals i hi ha un fort acoblament entre les variables característiques del sistema, fet que planteja un repte des de el punt de vista del control. L’objectiu d’aquest projecte és dissenyar estructures de control que puguin implementar-se en aquest sistema, tenint en compte les seves fortes no linealitats. Aquestes estructures de control estan ordenades des de les més senzilles fins les més complexes, i es fa una comparativa del comportament del sistema utilitzant cada una de les estructures. Totes les estructures de control dissenyades en aquest projecte es fan linealitzant el sistema al voltant d’un punt d’equilibri, això permet fer una aproximació lineal del sistema sempre i quan es trobi proper a una configuració determinada, la del punt d’equilibri. Si es linealitza el sistema s’arriba a un sistema linealitzat d’ordre molt elevat, donat que és incòmode treballar amb sistemes d’ordre elevat es redueix l’ordre del sistema. S’han realitzat dues reduccions d’ordre diferents i s’ha comparat el comportament del sistema aplicant-hi les estructures de control dissenyades amb les dues reduccions d’ordre

A kinetic study of the formation of smectic phases in novel liquid crystal ionogens

[EN] A multi-rate non-isothermal kinetic analysis of the isotropic-melt to liquid crystalline phase transition of novel liquid crystalline ionogenic copolymers, LCIs, the 10-(4-methoxyazobenzene-4'-oxy)decyl methacrylate]-co-2-(acrylamido-2-methyl-1-propanesulfonic acid)s, 10-MeOAzB/AMPS, copolymers, has been performed by means of calorimetric experiments. An analytical methodology which includes the study of the phase transition rate parameter, the determination of the activation energies by using Kissinger and Flynn-Wall-Ozawa models, and the study of the phase transition kinetics by the use of the Avrami theory, has been applied. The formation of the mesophases from the isotropic state occurred close to thermodynamic equilibrium. The results evidence the presence of several individual processes in the formation of liquid crystalline phases from the melt and a strong dependence of phase transition rates and activation energies with acid contents. A decrease in the phase transition rate, related to a decrease in the overall change of the transition entropy, has been observed. The final inhibition of the liquid crystal (LC) behaviour is ascribed to an exponential increase in the activation energy of the phase transition, promoted by strong acid aggregation. An optimum composition of the 10-MeOAzB/AMPS copolymers to achieve the dual characteristics of LCIs (ionogenic and liquid crystalline behaviour) requires acid concentrations capable of promoting structure-forming effects on the LC phases and the evolution of phase separated morphologies.The authors would like to acknowledge the Spanish Ministry of Science and Innovation, through the Research Projects ENE2007-67584-C03, UPOVCE-3E-013, ENE2011-28735-C02-01, IT-2009-0074 and three FPI and FPU predoctoral grants, and the financial support of the Generalitat Valenciana, through the Grisolia and Forteza programs and the ACOMP/2011/189 program. The Vice-rectorate for Research of UPV is also thanked for additional support through the PAID 05-09-4331, PAID-05-11/2806, and PAID 06-11-2037 projects.Martinez-Felipe, A.; Badia, J.; Santonja Blasco, L.; Imrie, C.; Ribes Greus, MD. (2013). A kinetic study of the formation of smectic phases in novel liquid crystal ionogens. European Polymer Journal. 49(6):1553-1563. https://doi.org/10.116/j.eurpolymj.2013.01.021S1553156349

Expression of adrenomedullin and its receptor during embryogenesis suggests autocrine or paracrine modes of action

The present study reports the developmental patterns of expression of adrenomedullin (AM) in rat and mouse embryos. AM is a novel multifunctional peptide recently isolated from a human pheochromocytoma, which has been shown to promote growth in a variety of mammalian cell lines. We have applied several techniques to investigate the localization of both the AM peptide and its receptor throughout development. Immunocytochemical detection has been performed using different specific antibodies against AM and its gene-related peptide pro-AM N-terminal 20 peptide. In situ hybridization showed the localization of the messenger RNAs for AM and its receptor. Western blot analysis together with reverse transcription-PCR gave further support to the localization of AM and its receptor in a variety of embryonic tissues. The localization of the receptor paralleled that of AM itself, suggesting an autocrine or paracrine mode of action. The spatio-temporal pattern of expression of AM in cardiovascular, neural, and skeletal-forming tissues as well as in the main embryonic internal organs is described. The primitive placenta, especially the giant trophoblastic cells, shows high levels of AM and AM receptor. The heart is the first organ that expresses AM during development. The kidney, lung, and developing tooth, in which epithelial-mesenchymal interactions are taking place, show specific patterns of AM expression. In several regions of the embryo, the patterns of AM expression correspond to the degree of differentiation. The possible involvement of AM in the control of embryonic invasion, proliferation, and differentiation is discussed

Adrenomedullin expression in the mouse mammary gland: evidence for the mature form in milk

Adrenomedullin (AM) is a recently identified amidated peptide produced by a variety of tissue types. We have investigated the involvement of AM and its receptor (AM-R) in developing mouse mammary glands and have examined what influence ovarian hormones have on AM and AM-R expression in this system. Tissues from ductal morphogenesis, virgin adult, pregnancy, and lactation stages were assessed for AM and AM-R by molecular, biochemical and immunohistochemical techniques. Results from these studies indicated that messenger RNA for AM and AM-R and immunoreactivity for AM were expressed in the luminal epithelium of small and large ducts and in terminal end buds. Immunoreactive AM was identified as a cytoplasm component of ductal cells, with some cells also having nuclear staining. Western blot analysis of mammary gland tissues yielded two molecular mass species (M(r) 14,000 and 18,500) of AM immunoreactivity in the mammary gland for the above developmental stages, consistent with processed intermediate and prohormone forms respectively. Ovariectomy alone or followed by hormonal treatments did not alter the expression pattern for these two proteins. By Western blot, the fully processed AM form (M(r) 6000) was identified in milk extracts from lactating glands. These data suggest a potential role for AM and its receptor in the maintenance of mammary gland homeostasis and suggests a potential role for AM in development of the newborn

Expression of adrenomedullin and proadrenomedullin N-terminal 20 peptide in human and rat prostate

Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are two recently discovered hypotensive peptides translated from the same message transcript (preproAM mRNA). In this article we report the presence of AM, PAMP, and their mRNA in human and rat prostate and of AM receptor mRNA in rat prostate. PreproAM mRNA was found in the epithelium of normal human and rat prostate glands by in situ hybridization. In humans, it was mainly expressed in the basal cells. In rat, its expression was higher in the ducts than in the acini of all the prostate lobes. Immunocytochemistry identified a similar distribution pattern for AM compared with its mRNA but showed different locations for AM and PAMP immunoreactivity. The former was widespread in the epithelia, whereas the latter was almost exclusively found in neuroendocrine cells. In rat, Western blot analysis confirmed the presence of high levels of AM peptide in the ventral lobe and of its precursor in the ventral and dorsolateral lobes. Immunoreactivity for serotonin, chromogranin A, PAMP, and AM defined four subpopulations of prostate neuroendocrine-like cells in rat, a cell type that has not been previously described

Adrenomedullin functions as an important tumor survival factor in human carcinogenesis

Adrenomedullin (AM) is a pluripotent regulatory peptide initially isolated from a human pheochromocytoma (adrenal tumor) and subsequently shown to play a critical role in cancer cell division, tumor neovascularization, and circumvention of programmed cell death, thus it is an important tumor cell survival factor underlying human carcinogenesis. A variety of neural and epithelial cancers have been shown to produce abundant amounts of AM. Recent findings have implicated elevation of serum AM with the onset of malignant expression. In addition, patients with tumors producing high levels of this peptide have a poor prognostic clinical outcome. Given that most human epithelial cancers display a microenvironment of reduced oxygen tension, it is interesting to note that AM and several of its receptors are upregulated during hypoxic insult. The existence of such a regulatory pathway has been implicated as the basis for the overexpression of AM/AM-R in human malignancies, thereby generating a subsequent autocrine/paracrine growth advantage for the tumor cell. Furthermore, AM has been implicated as a potential immune suppressor substance, inhibiting macrophage function and acting as a newly identified negative regulator of the complement cascade, protective properties which may help cancer cells to circumvent immune surveillance. Hence, AM's traditional participation in normal physiology (cited elsewhere in this issue) can be extended to a primary player in human carcinogenesis and may have clinical relevance as a biological target for the intervention of tumor progression

Depressed adrenomedullin in the embryonic transforming growth factor-beta1 null mouse becomes elevated postnatally

Transforming growth factor-beta (TGF-beta) and adrenomedullin are multifunctional regulatory proteins which are expressed in developing embryonic and adult tissues. Because of their colocalization, TGF-beta1 and adrenomedullin may be able to coordinately act to influence development and differentiation. In order to learn more about the biology of adrenomedullin in the absence of the effects of TGF-beta1 in vivo, we examined adrenomedullin in the TGF-beta1 null mouse. A generally lower amount of adrenomedullin was detected by immunohistochemical staining analysis in multiple tissues from embryonic TGF-beta1 null mice compared to wildtype animals, including the heart, lung, brain, liver, and kidney, among others. In contrast, immunohistochemical staining for adrenomedullin was more intense in tissues of the postnatal TGF-beta1 null mouse compared to the wildtype mouse. These observations were confirmed by quantitative real time RT-PCR for adrenomedullin in both embryos and postnatal animals, as well as in cultured mouse embryo fibroblasts from TGF-beta1 null and wildtype mice. In addition, when cultured mouse embryo fibroblasts were treated with a neutralizing monoclonal antibody against TGF-beta1, the levels of adrenomedullin expression were statistically reduced compared to untreated cells. Our data show that expression of adrenomedullin is reduced in tissues of the developing embryonic TGF-beta1 null mouse compared to the wildtype mouse, but increases during postnatal development in TGF-beta1 null mice. The elevated expression of adrenomedullin which occurs postnatally in the TGF-beta1 null mouse may be a cause or a consequence of the multifocal wasting syndrome which is characteristic of postnatal TGF-beta1 null mice

Expression of heterogeneous nuclear ribonucleoprotein A2/B1 changes with critical stages of mammalian lung development

Recent reports have demostrated a link between expression of members of the family of heterogeneous nuclear ribonucleoproteins (hnRNPs) and cancer. Overexpression of hnRNP A2/B1 correlated with the eventual development of lung cancer in three different clinical cohorts. We have studied the expression of hnRNP A2/B1 messenger RNA (mRNA) and protein during mammalian development. The expression of hnRNP A2/B1 mRNA and protein are parallel but change dynamically during critical periods in mouse pulmonary development. hnRNP A2/B1 is first detected in the lung in the early pseudoglandular period, peaks at the beginning of the canalicular period, and remains high during the saccular (alveolar) period. In mouse and rat, hnRNP A2/B1 expression is first evident in the earliest lung buds. As lung development progresses, the cuboidal epithelial cells of the distal primitive alveoli show high levels of the ribonucleoprotein, which is almost undetectable in the proximal conducting airways. The expression of hnRNP A2/ B1 is restricted in mature lung. Similar dynamic pattern of expression through lung development was also found in rat and human lung. Upregulated expression of hnRNP A2/B1 at critical periods of lung development was comparable to the level of expression found in lung cancers and preneoplastic lesions and is consistent with hnRNP A2/B1 overexpression playing an oncodevelopmental role

Expression of complement factor H by lung cancer cells: effects on the activation of the alternative pathway of complement

The complement system is important in immunosurveillance against tumors. However, malignant cells are usually resistant to complement-mediated lysis. In this study, we examine the expression of factor H, an inhibitor of complement activation, and factor H-like protein 1 (FHL-1), its alternatively spliced form, in lung cancer. We also evaluate the potential effect of factor H/FHL-1 in the protection of lung cancer cells against the activation of the complement cascade. By Northern blot analysis we demonstrate a high expression of factor H and FHL-1 in most non-small cell lung cancer cell lines, although neuroendocrine pulmonary tumors (small cell lung carcinoma and carcinoid cell lines) had undetectable levels. Western blot analysis of conditioned medium showed the active secretion of factor H and FHL-1 by cells that were positive by Northern blot. Expression of factor H/FHL-1 mRNA was also shown in a series of non-small cell lung cancer biopsies by in situ hybridization. Interestingly, many cultured lung cancer cells were able to bind fluorescence-labeled factor H to their surfaces. Deposition of C3 fragments from normal human serum on H1264, a lung adenocarcinoma cell line, was more efficient when factor H/FHL-1 activity was blocked by specific antibodies. Blocking factor H/FHL-1 activity also enhanced the release of anaphylatoxin C5a and moderately increased the susceptibility of these cells to complement-mediated cytotoxicity. In summary, we demonstrate the expression of factor H and FHL-1 by some lung cancer cells and analyze the contribution of these proteins to the protection against complement activation

Expression of proadrenomedullin derived peptides in the mammalian pituitary: co-localization of follicle stimulating hormone and proadrenomedullin N-20 terminal peptide-like peptide in the same secretory granules of the gonadotropes

Expression of proadrenomedullin-derived peptides in the rat, cow and human pituitary was studied by a variety of techniques. Immunocytochemical detection showed a widespread expression of adrenomedullin peptide in the adenohypophysis and the neural lobe, with low expression in the intermediate pituitary. Proadrenomedullin N-20 terminal peptide (PAMP)-immunoreactivity was also present in the anterior pituitary but showed a more marked heterogeneous distribution, with cells going from very strong to negative immunostaining. Lower levels of PAMP were found in the neural lobe. Interestingly, the distribution of adrenomedullin and PAMP immunoreactivity in the anterior pituitary did not completely overlap. In the present study, we concentrated our efforts to determine which cell type of the adenohypophysis expresses PAMP. Paraffin and semithin serial sections immunostained for PAMP and the classical pituitary hormones revealed that a subpopulation of the gonadotropes expresses high levels of PAMP-immunoreactive material. Ultrastructural analysis clearly showed PAMP-immunoreactivity in the follicle stimulating hormone (FSH)-containing large secretory granules of the gonadotropes, suggesting simultaneous secretion of PAMP and FSH by this cell type. Three mouse adenohypophysis-derived cell lines (AtT20, GH3, and alphaT3-1 derived from corticotropes, lacto/somatotropes and gonadotropes, respectively) were also analysed and showed expression of both proadrenomedullin-derived peptides and their mRNA. Functional studies in these three cell lines showed that neither adrenomedullin nor PAMP was able to stimulate cAMP production in our experimental conditions. Taken together, our results support that proadrenomedullin derived peptides are expressed in the pituitary in cell-specific and not overlapping patterns, that could be explained by differences in postranslational processing. Our data showing costorage of PAMP and FSH in the same secretory granules open a way by which PAMP could be involved in the control of reproductive physiology in a coordinated manner with FSH