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101.
102.
José-Luis Usó-Doménech Josué Antonio Nescolarde Selva Mónica Belmonte Requena 《Foundations of Science》2016,21(4):615-630
In the Reality we know, we cannot say if something is infinite whether we are doing Physics, Biology, Sociology or Economics. This means we have to be careful using this concept. Infinite structures do not exist in the physical world as far as we know. So what do mathematicians mean when they assert the existence of ω (the mathematical symbol for the set of all integers)? There is no universally accepted philosophy of mathematics but the most common belief is that mathematics touches on another worldly absolute truth. Many mathematicians believe that mathematics involves a special perception of an idealized world of absolute truth. This comes in part from the recognition that our knowledge of the physical world is imperfect and falls short of what we can apprehend with mathematical thinking. The objective of this paper is to present an epistemological rather than an historical vision of the mathematical concept of infinity that examines the dialectic between the actual and potential infinity. 相似文献
103.
Yesica R. Nievas Veronica M. Coceres Victor Midlej Wanderley de Souza Marlene Benchimol Antonio Pereira-Neves Ajay A. Vashisht James A. Wohlschlegel Patricia J. Johnson Natalia de Miguel 《Cellular and molecular life sciences : CMLS》2018,75(12):2211-2226
Trichomonas vaginalis is a common sexually transmitted parasite that colonizes the human urogenital tract, where it remains extracellular and adheres to epithelial cells. Infections range from asymptomatic to highly inflammatory, depending on the host and the parasite strain. Despite the serious consequences associated with trichomoniasis disease, little is known about parasite or host factors involved in attachment of the parasite-to-host epithelial cells. Here, we report the identification of microvesicle-like structures (MVs) released by T. vaginalis. MVs are considered universal transport vehicles for intercellular communication as they can incorporate peptides, proteins, lipids, miRNA, and mRNA, all of which can be transferred to target cells through receptor–ligand interactions, fusion with the cell membrane, and delivery of a functional cargo to the cytoplasm of the target cell. In the present study, we demonstrated that T. vaginalis release MVs from the plasma and the flagellar membranes of the parasite. We performed proteomic profiling of these structures demonstrating that they possess physical characteristics similar to mammalian extracellular vesicles and might be selectively charged with specific protein content. In addition, we demonstrated that viable T. vaginalis parasites release large vesicles (LVs), membrane structures larger than 1 µm that are able to interact with other parasites and with the host cell. Finally, we show that both populations of vesicles present on the surface of T vaginalis are induced in the presence of host cells, consistent with a role in modulating cell interactions. 相似文献
104.
Sanna S Jackson AU Nagaraja R Willer CJ Chen WM Bonnycastle LL Shen H Timpson N Lettre G Usala G Chines PS Stringham HM Scott LJ Dei M Lai S Albai G Crisponi L Naitza S Doheny KF Pugh EW Ben-Shlomo Y Ebrahim S Lawlor DA Bergman RN Watanabe RM Uda M Tuomilehto J Coresh J Hirschhorn JN Shuldiner AR Schlessinger D Collins FS Davey Smith G Boerwinkle E Cao A Boehnke M Abecasis GR Mohlke KL 《Nature genetics》2008,40(2):198-203
105.
Donadi EA Castelli EC Arnaiz-Villena A Roger M Rey D Moreau P 《Cellular and molecular life sciences : CMLS》2011,68(3):369-395
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. 相似文献
106.
Hashibe M McKay JD Curado MP Oliveira JC Koifman S Koifman R Zaridze D Shangina O Wünsch-Filho V Eluf-Neto J Levi JE Matos E Lagiou P Lagiou A Benhamou S Bouchardy C Szeszenia-Dabrowska N Menezes A Dall'Agnol MM Merletti F Richiardi L Fernandez L Lence J Talamini R Barzan L Mates D Mates IN Kjaerheim K Macfarlane GJ Macfarlane TV Simonato L Canova C Holcátová I Agudo A Castellsagué X Lowry R Janout V Kollarova H Conway DI McKinney PA Znaor A Fabianova E Bencko V Lissowska J Chabrier A Hung RJ 《Nature genetics》2008,40(6):707-709
Alcohol is an important risk factor for upper aerodigestive cancers and is principally metabolized by alcohol dehydrogenase (ADH) enzymes. We have investigated six ADH genetic variants in over 3,800 aerodigestive cancer cases and 5,200 controls from three individual studies. Gene variants rs1229984 (ADH1B) and rs1573496 (ADH7) were significantly protective against aerodigestive cancer in each individual study and overall (P = 10(-10) and 10(-9), respectively). These effects became more apparent with increasing alcohol consumption (P for trend = 0.0002 and 0.065, respectively). Both gene effects were independent of each other, implying that multiple ADH genes may be involved in upper aerodigestive cancer etiology. 相似文献
107.
Money demand functions have long been known to be frequently subject to structural change. Since their use for optimal monetary policy design is basically a forecasting exercise, it is crucial to analyse the effect of time instability on the quality of their forecasts. We discuss in this paper whether instability of demand for money functions precludes their use for policy experiments, analysing a 1963–84 sample for the UK which has been widely used in the literature. © 1998 John Wiley & Sons, Ltd. 相似文献
108.
Roman Goetzke Antonio Sechi Laura De Laporte Sabine Neuss Wolfgang Wagner 《Cellular and molecular life sciences : CMLS》2018,75(18):3297-3312
Mechanical stimulation affects growth and differentiation of stem cells. This may be used to guide lineage-specific cell fate decisions and therefore opens fascinating opportunities for stem cell biology and regenerative medicine. Several studies demonstrated functional and molecular effects of mechanical stimulation but on first sight these results often appear to be inconsistent. Comparison of such studies is hampered by a multitude of relevant parameters that act in concert. There are notorious differences between species, cell types, and culture conditions. Furthermore, the utilized culture substrates have complex features, such as surface chemistry, elasticity, and topography. Cell culture substrates can vary from simple, flat materials to complex 3D scaffolds. Last but not least, mechanical forces can be applied with different frequency, amplitude, and strength. It is therefore a prerequisite to take all these parameters into consideration when ascribing their specific functional relevance—and to only modulate one parameter at the time if the relevance of this parameter is addressed. Such research questions can only be investigated by interdisciplinary cooperation. In this review, we focus particularly on mesenchymal stem cells and pluripotent stem cells to discuss relevant parameters that contribute to the kaleidoscope of mechanical stimulation of stem cells. 相似文献
109.
Mireia Pérez-Verdaguer Jesusa Capera María Ortego-Domínguez Joanna Bielanska Núria Comes Rafael J. Montoro Marta Camps Antonio Felipe 《Cellular and molecular life sciences : CMLS》2018,75(21):4059-4075
The voltage-dependent potassium channel Kv1.3 participates in peripheral insulin sensitivity. Genetic ablation of Kv1.3 triggers resistance to diet-induced weight gain, thereby pointing to this protein as a pharmacological target for obesity and associated type II diabetes. However, this role is under intense debate because Kv1.3 expression in adipose tissue raises controversy. We demonstrated that Kv1.3 is expressed in white adipose tissue from humans and rodents. Moreover, other channels, such as Kv1.1, Kv1.2, Kv1.4 and especially Kv1.5, from the same Shaker family are also present. Although elevated insulin levels and adipogenesis remodel the Kv phenotype, which could lead to multiple heteromeric complexes, Kv1.3 markedly participates in the insulin-dependent regulation of glucose uptake in mature adipocytes. Adipocyte differentiation increased the expression of Kv1.3, which is targeted to caveolae by molecular interactions with caveolin 1. Using a caveolin 1-deficient 3T3-L1 adipocyte cell line, we demonstrated that the localization of Kv1.3 in caveolar raft structures is important for proper insulin signaling. Insulin-dependent phosphorylation of the channel occurs at the onset of insulin-mediated signaling. However, when Kv1.3 was spatially outside of these lipid microdomains, impaired phosphorylation was exhibited. Our data shed light on the putative role of Kv1.3 in weight gain and insulin-dependent responses contributing to knowledge about adipocyte physiology. 相似文献
110.
Jose Maria Aguilar-Camacho Jose Luis Carballo Jose Antonio Cruz-Barraza 《Journal of Natural History》2018,52(19-20):1311-1332
Two new species of Tedania (Porifera: Demospongiae: Poecilosclerida) are described from the Mexican Pacific. Tedania (Tedania) tropicalis sp. nov. is an encrusting to massive sponge having ectosomal tylotes with microspined heads, choanosomal styles and onychaetes. Tedania (Tedania) fulvum sp. nov. is a thinly encrusting sponge having ectosomal tylotes with smooth heads, choanosomal styles and onychaetes. Tables for all the Tedania (subgenera Tedania and Tedaniopsis) and Trachytedania species described worldwide are included. We suggest that species of Tedania and Trachytedania bearing ectosomal diactinal spicules (excluding Tedania (Stylotedania)) can be separated in two main groups: those having choanosomal monactinal spicules and those with choanosomal diactinal spicules.
www.zoobank.org/urn:lsid:zoobank.org:pub:5B212DC3-3827-44D5-8E63-3E652BCB29E6 相似文献