964 resultados para Lamina propria
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Questo elaborato di tesi ha lo scopo di illustrare un'applicazione realizzata per dispositivi Android in grado di localizzare l'utente all'interno di un ambiente indoor sfruttando l'utilizzo dei Beacon e dare una valutazione dei risultati ottenuti. L'utente potrà registrare i dispositivi Beacon in suo possesso all'interno dell'applicazione, caricare la planimetria di un ambiente e configurarlo indicando esattamente quale Beacon si trova in una determinata posizione. Infine potrà scegliere quale tra i tre algoritmi implementati (Prossimità, Triangolazione e Fingerprinting) utilizzare per visualizzare la propria posizione sulla mappa. I tre algoritmi sono stati sottoposti a vari test che hanno permesso di analizzare le differenze tra di essi in termini di accuratezza e le performance generali dell'applicativo.
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Negli ultimi anni, l'avanzamento incredibilmente rapido della tecnologia ha portato allo sviluppo e alla diffusione di dispositivi elettronici portatili aventi dimensioni estremamente ridotte e, allo stesso tempo, capacità computazionali molto notevoli. Più nello specifico, una particolare categoria di dispositivi, attualmente in forte sviluppo, che ha già fatto la propria comparsa sul mercato mondiale è sicuramente la categoria dei dispositivi Wearable. Come suggerisce il nome, questi sono progettati per essere letteralmente indossati, pensati per fornire continuo supporto, in diversi ambiti, a chi li utilizza. Se per interagire con essi l’utente non deve ricorrere obbligatoriamente all'utilizzo delle mani, allora si parla di dispositivi Wearable Hands Free. Questi sono generalmente in grado di percepire e catture l’input dell'utente seguendo tecniche e metodologie diverse, non basate sul tatto. Una di queste è sicuramente quella che prevede di modellare l’input dell’utente stesso attraverso la sua voce, appoggiandosi alla disciplina dell’ASR (Automatic Speech Recognition), che si occupa della traduzione del linguaggio parlato in testo, mediante l’utilizzo di dispositivi computerizzati. Si giunge quindi all’obiettivo della tesi, che è quello di sviluppare un framework, utilizzabile nell’ambito dei dispositivi Wearable, che fornisca un servizio di riconoscimento vocale appoggiandosi ad uno già esistente, in modo che presenti un certo livello di efficienza e facilità di utilizzo. Più in generale, in questo documento si punta a fornire una descrizione approfondita di quelli che sono i dispositivi Wearable e Wearable Hands-Free, definendone caratteristiche, criticità e ambiti di utilizzo. Inoltre, l’intento è quello di illustrare i principi di funzionamento dell’Automatic Speech Recognition per passare poi ad analisi, progettazione e sviluppo del framework appena citato.
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Lo scopo di questa attività è approfondire le conoscenze sul processo di riempimento a caldo noto come nitro-hot-fill (NHF) utilizzato per contenitori in PET. Il nostro obiettivo è quello di simulare su scala di laboratorio il processo industriale al fine di ottimizzarne i parametri e aumentare la stabilità dei contenitori anche attraverso l’utilizzo di materie prime con caratteristiche migliorate utilizzando formulazioni adatte ai trattamenti a caldo. Il processo consiste nel riempimento della bottiglia ad una temperatura tra gli 80°/85°C, successivo al quale vi è l’iniezione di azoto al fine di evitare l’implosione durante il raffreddamento fino a temperatura ambiente. Questo settore del mercato è in forte crescita, molte bevande infatti hanno la necessità di un contenitore asettico; il processo di NHF ha il vantaggio di utilizzare il calore del prodotto stesso al fine di rendere la bottiglia sterile. Da qui nascono le criticità legate al processo, occorre prendere diversi accorgimenti al fine di rendere processabile in questo modo una bottiglia, infatti l’aumento di pressione interna dovuto all’iniezione di azoto si accompagna una temperatura vicina alla temperatura di transizione vetrosa. La nostra attività di ricerca ha focalizzato la propria attenzione sul design della bottiglia, sul processo di stiro-soffiaggio, sull’influenza dell’umidità assorbita nel PET, sul materiale utilizzato e su altri parametri di processo al fine di produrre contenitori in grado di resistere al riempimento NHF.
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Aimed to identify, for assessing the tillering dynamics and morphogenesis , strategy (s ) suitable ( s) defoliation management to optimize the appearance of tillers and biomass of Urochloa Brizantha syn. Brachiaria brizantha cv. Marandu ( marandugrass ) throughout the year. The experiment was conducted from January 2013 to May 2014 were studied three strategies defoliation: Marandugrass with 30 cm throughout the experimental period (constant height); Marandugrass 15 cm in winter, the spring 30 cm and 45 cm in summer (increasing height); and Marandugrass 45 cm in winter, the spring 30 cm and 15 cm in summer (descending height). The experimental design was completely randomized in a split plot in time, with four replications. In winter, in the spring and summer, the following variables were calculated: appearance rate (TApP), mortality (TMoP) and survival (TSoP) of tillers, balance (BAL) between TApP and TMoP, stability index (IE) numbers of tillers and leaf elongation rates and stem, length of leaf blade and stem, leaf senescence rate, phyllochron and duration of life of the sheet. The TAPP was higher in the early spring and summer. For TMoP, the highest values were in the late spring and summer. The balance between TApP and TMoP was negative in winter and late spring, regardless of defoliation strategy. There was no difference in IE between the heights of the canopy during winter and late spring .. The number of tillers was higher in early spring and summer and lower in winter and late spring. The defoliation strategies have not changed phyllochron, leaf elongation rate. In spring and summer, there were increases in the rates of appearance, elongation and leaf senescence and, furthermore, decreased life span and phyllochron sheet. The plant height with increasing showed a lower rate of senescence and lower culm length in the spring. To increase the number of tillers marandu, it is advantageous to handle the plant with increasing height, ie, 15 cm in autumn and winter, the spring 30 cm and 45 cm in summer.The maintaining of B. brizantha cv. Marandu with fixed height of 30 cm or with variations between 15 and 45cm from the fall/winter to summer, does not influence the appearance and the growth of leaves per tiller, which indicates great flexibility on management defoliation in this forage plant.
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In questo TFM affronteremo un argomento di grande attualità le cui radici risalgono, però, a un passato ben più remoto: la questione del burocratese, termine con accezione negativa coniato in tempi relativamente recenti per descrivere lo stile comunicativo della pubblica amministrazione che, lungi dal restare confinato in un ambito specialistico della comunicazione, pervade ormai ogni sfera della vita quotidiana, rendendola sempre più complessa in un momento storico delicato dove l’equivoco è dietro l’angolo e spesso cela non pochi pericoli. Il presente lavoro si divide sostanzialmente in due parti. Nella prima, tracceremo una premessa teorica toccando le seguenti tematiche: il ruolo del/la docente di italiano LS (con particolare attenzione all’insegnamento agli adulti), le motivazioni scientifiche e personali che stanno alla base della scelta di questo argomento per un TFM, un breve ripasso delle principali tappe che hanno definito il dibattito sulla questione linguistica in Italia, le caratteristiche linguistiche e testuali del linguaggio burocratico amministrativo e un breve excursus sulle direttive e suggerimenti per la sua semplificazione. Nella seconda parte del lavoro (dal capitolo 3) sarà presentata in dettaglio l’unità didattica dal titolo Parla come mangi!, messa in pratica con un gruppo di studenti e studentesse di italiano di nivel avanzado 1 (B2 del QCER) della Escuela Oficial de Idiomas di Alcorcón, nell’ambito del tirocinio propedeutico all’ottenimento del titolo di Máster en formación del Profesorado de ESO, Bachillerato, FP y enseñanzas de idiomas. L’obiettivo finale delle attività proposte è stato quello di permettere alla classe di familiarizzare con le strutture lessicali, morfosintattiche e testuali del burocratese. Attraverso attività disegnate per il coinvolgimento delle quattro abilità fondamentali e suddivise in tre grandi categorie (pubblica amministrazione, trasporti e comunicazione formale scritta), gli alunni e le alunne hanno messo alla prova e migliorato la propria competenza sociolinguistica in contesti dove l’eccessiva formalità spesso mette in difficoltà gli/le stessi/e nativi/e.
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Both low-dimensional bar-coded metal oxide layers, which exhibit molecular hinging, and free-standing organic nanostructures can be obtained from unique nanofibers of vanadium oxide (VOx). The nanofibers are successfully synthesized by a simple chemical route using an ethanolic solution of vanadium pentoxide xerogel and dodecanethiol resulting in a double bilayered laminar turbostratic structure. The formation of vanadium oxide nanofibers is observed after hydrothermal treatment of the thiol-intercalated xerogel, resulting in typical lengths in the range 2–6 µm and widths of about 50–500 nm. We observe concomitant hinging of the flexible nanofiber lamina at periodic hinge points in the final product on both the nanoscale and molecular level. Bar-coded nanofibers comprise alternating segments of organic–inorganic (thiols–VOx) material and are amenable to segmented, localized metal nanoparticle docking. Under certain conditions free-standing bilayered organic nanostructures are realized.
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We report the comparative structural-vibrational study of nanostructures of nanourchins, nanotubes, and nanorods of vanadium oxide. The tube walls comprise layers of vanadium oxide with the organic surfactant intercalated between atomic layers. Both Raman scattering and infrared spectroscopies showed that the structure of nanourchins, nanotubes, and nanorods of vanadium oxide nanocomposite are strongly dependent on the valency of the vanadium, its associated interactions with the organic surfactant template, and on the packing mechanism and arrangement of the surfactant between vanadate layers. Accurate assignment of the vibrational modes to the V-O coordinations has allowed their comparative classification and relation to atomic layer structure. Although all structures are formed from the same precursor, differences in vanadate conformations due to the hydrothermal treatment and surfactant type result in variable degrees of crystalline order in the final nanostructure. The nanotube-containing nanourchins contain vanadate layers in the nanotubes that are in a distorted γ- V5+ conformation, whereas the the nanorods, by comparison, show evidence for V5+ and V4+ species-containing ordered VOx lamina.
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Tissue engineering of biomimetic skeletal muscle may lead to development of new therapies for myogenic repair and generation of improved in vitro models for studies of muscle function, regeneration, and disease. For the optimal therapeutic and in vitro results, engineered muscle should recreate the force-generating and regenerative capacities of native muscle, enabled respectively by its two main cellular constituents, the mature myofibers and satellite cells (SCs). Still, after 20 years of research, engineered muscle tissues fall short of mimicking contractile function and self-repair capacity of native skeletal muscle. To overcome this limitation, we set the thesis goals to: 1) generate a highly functional, self-regenerative engineered skeletal muscle and 2) explore mechanisms governing its formation and regeneration in vitro and survival and vascularization in vivo.
By studying myogenic progenitors isolated from neonatal rats, we first discovered advantages of using an adherent cell fraction for engineering of skeletal muscles with robust structure and function and the formation of a SC pool. Specifically, when synergized with dynamic culture conditions, the use of adherent cells yielded muscle constructs capable of replicating the contractile output of native neonatal muscle, generating >40 mN/mm2 of specific force. Moreover, tissue structure and cellular heterogeneity of engineered muscle constructs closely resembled those of native muscle, consisting of aligned, striated myofibers embedded in a matrix of basal lamina proteins and SCs that resided in native-like niches. Importantly, we identified rapid formation of myofibers early during engineered muscle culture as a critical condition leading to SC homing and conversion to a quiescent, non-proliferative state. The SCs retained natural regenerative capacity and activated, proliferated, and differentiated to rebuild damaged myofibers and recover contractile function within 10 days after the muscle was injured by cardiotoxin (CTX). The resulting regenerative response was directly dependent on the abundance of SCs in the engineered muscle that we varied by expanding starting cell population under different levels of basic fibroblast growth factor (bFGF), an inhibitor of myogenic differentiation. Using a dorsal skinfold window chamber model in nude mice, we further demonstrated that within 2 weeks after implantation, initially avascular engineered muscle underwent robust vascularization and perfusion and exhibited improved structure and contractile function beyond what was achievable in vitro.
To enhance translational value of our approach, we transitioned to use of adult rat myogenic cells, but found that despite similar function to that of neonatal constructs, adult-derived muscle lacked regenerative capacity. Using a novel platform for live monitoring of calcium transients during construct culture, we rapidly screened for potential enhancers of regeneration to establish that many known pro-regenerative soluble factors were ineffective in stimulating in vitro engineered muscle recovery from CTX injury. This led us to introduce bone marrow-derived macrophages (BMDMs), an established non-myogenic contributor to muscle repair, to the adult-derived constructs and to demonstrate remarkable recovery of force generation (>80%) and muscle mass (>70%) following CTX injury. Mechanistically, while similar patterns of early SC activation and proliferation upon injury were observed in engineered muscles with and without BMDMs, a significant decrease in injury-induced apoptosis occurred only in the presence of BMDMs. The importance of preventing apoptosis was further demonstrated by showing that application of caspase inhibitor (Q-VD-OPh) yielded myofiber regrowth and functional recovery post-injury. Gene expression analysis suggested muscle-secreted tumor necrosis factor-α (TNFα) as a potential inducer of apoptosis as common for muscle degeneration in diseases and aging in vivo. Finally, we showed that BMDM incorporation in engineered muscle enhanced its growth, angiogenesis, and function following implantation in the dorsal window chambers in nude mice.
In summary, this thesis describes novel strategies to engineer highly contractile and regenerative skeletal muscle tissues starting from neonatal or adult rat myogenic cells. We find that age-dependent differences of myogenic cells distinctly affect the self-repair capacity but not contractile function of engineered muscle. Adult, but not neonatal, myogenic progenitors appear to require co-culture with other cells, such as bone marrow-derived macrophages, to allow robust muscle regeneration in vitro and rapid vascularization in vivo. Regarding the established roles of immune system cells in the repair of various muscle and non-muscle tissues, we expect that our work will stimulate the future applications of immune cells as pro-regenerative or anti-inflammatory constituents of engineered tissue grafts. Furthermore, we expect that rodent studies in this thesis will inspire successful engineering of biomimetic human muscle tissues for use in regenerative therapy and drug discovery applications.
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During the last glacial termination, the upper North Pacific Ocean underwent dramatic and rapid changes in oxygenation that lead to the transient intensification of oxygen minimum zones (OMZs), recorded by the widespread occurrence of laminated sediments on circum-Pacific continental margins. We present a new laminated sediment record from the mid-depth (1100 m) northern Bering Sea margin that provides insight into these deglacial OMZ maxima with exceptional, decadal-scale detail. Combined ultrahigh-resolution micro-X-ray-fluorescence (micro-XRF) data and sediment facies analysis of laminae reveal an alternation between predominantly terrigenous and diatom-dominated opal sedimentation. The diatomaceous laminae are interpreted to represent spring/summer productivity events related to the retreating sea ice margin.We identified five laminated sections in the deglacial part of our site. Lamina counts were carried out on these sections and correlated with the Bølling-Allerød and Preboreal phases in the North Greenland Ice Core (NGRIP) oxygen isotope record, indicating an annual deposition of individual lamina couplets (varves). The observed rapid decadal intensifications of anoxia, in particular within the Bølling-Allerød, are tightly coupled to short-term warm events through increases in regional export production. This dependence of laminae formation on warmer temperatures is underlined by a correlation with published Bering Sea sea surface temperature records and d18O data of planktic foraminifera from the Gulf of Alaska. The rapidity of the observed changes strongly implies a close atmospheric teleconnection between North Pacific and North Atlantic regions.We suggest that concomitant increases in export production and subsequent remineralization of organic matter in the Bering Sea, in combination with oxygen-poor waters entering the Being Sea, drove down oxygen concentrations to values below 0.1ml/l and caused laminae preservation. Calculated benthic-planktic ventilation ages show no significant variations throughout the last deglaciation, indicating that changes in formation rates or differing sources of North Pacific mid-depth waters are not prime candidates for strengthening the OMZ at our site. The age models established by our correlation procedure allow for the determination of calendar age control points for the Bølling-Allerød and the Preboreal that are independent of the initial radiocarbon-based chronology. Resulting surface reservoir ages range within 730-990 yr during the Bølling-Allerød, 800-1100 yr in the Younger Dryas, and 765-775 yr for the Preboreal.
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The distribution of diatoms, coccolithophores and planktic foraminifers mirrored the hydrographic and trophic conditions of the surface ocean (0-100 m) across the upwelling area off the Oman coast to the central Arabian Sea during May/June 1997 and July/August 1995. The number of diatoms was increased in waters with local temperature minimum and enhanced nutrient concentration (nitrate, phosphate, silicate) caused by upwelling. Vegetative cells of Chaetoceros dominated the diatom assemblage in the coastal upwelling area. Towards the more nutrient depleted and stratified surface waters to the southeast, the number of diatoms decreased, coccolithophore and planktic foraminiferal numbers increased, and floral and faunal composition changed. In particular, the transition between the eutrophic upwelling region off Oman and the oligotrophic central Arabian Sea was marked by moderate nutrient concentration, and high coccolithophore and foraminifer numbers. Florisphaera profunda, previously often referred as a 'lower-photic-zone-species', was frequent in water depths as shallow as 20 m, and at high nutrient concentration up to 14 µmol NO3/l and 1.2 µmol PO4/. To the oligotrophic southeast of the divergence, cell densities of coccolithophores declined and Umbellosphaera irregularis prevailed throughout the water column down to 100 m depth. In general, total coccolithophore numbers were limited by nutrient threshold concentration, with low numbers (<10*10**3 cells/l) at high [NO3] and [PO4], and high numbers (>70*10**3 cells/l) at low [NO3] and [PO4]. The components of the complex microplankton succession, diatoms, coccoliths and planktic foraminifers (and possibly others), should ideally be used as a combined paleoceanographic proxy. Consequently, models on plankton ecology should be resolved at least for the seasonality, to account for the bias of paleoceanographic transfer calculations.
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Foulden Maar is a highly resolved maar lake deposit from the South Island of New Zealand comprising laminated diatomite punctuated by numerous diatomaceous turbidites. Basaltic clasts found in debris flow deposits at the base of the cored sedimentary sequence yielded two new 40Ar/39Ar dates of 24.51±0.24 Ma and 23.38±0.24 Ma (2sigma). The younger date agrees within error with a previously published 40Ar/39Ar date of 23.17±0.19 Ma from a basaltic dyke adjacent to the maar crater. The diatomite is inferred to have been deposited over several tens of thousands of years in the latest Oligocene/earliest Miocene, and may have overlapped with the period of rapid glaciation and subsequent deglaciation of Antarctica known as the Mi-1 event. Sediment magnetic properties and SEM measurements indicate that the magnetic signal is dominated by pseudo-single domain pyrrhotite. The most likely source of detrital pyrrhotite is schist country rock fragments from the inferred tephra ring created by the phreatomagmatic eruption that formed the maar. Variations in magnetic concentration and lamina thickness indicate a decrease in erosional input and increase in diatom productivity throughout the depositional period, suggesting a long-term (tens of thousands of years) climatic change in New Zealand in the latest Oligocene/earliest Miocene.
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Flux of bulk components, carbonate- and silicate-bearing skeleton organisms, and the d15N-isotopic signal were investigated on a 1-year time-series sediment trap deployed at the pelagic NU mooring site (Namibia Upwelling, ca. 29°S, 13°E) in the central Benguela System. The flux of bulk components mostly shows bimodal seasonality with major peaks in austral summer and winter, and moderate to low export in austral fall and spring. The calcium carbonate fraction dominates the export of particulates throughout the year, followed by lithogenic and biogenic opal. Planktonic foraminifera and coccolithophorids are major components of the carbonate fraction, while diatoms clearly dominate the biogenic opal fraction. Bulk d15N isotopic composition of particulate matter is positively correlated with the total mass flux during summer and fall, while negatively correlated during winter and spring. Seasonal changes in the intensity of the main oceanographic processes affecting the NU site are inferred from variations in bulk component flux, and in the flux and diversity patterns of individual species or group of species. Influence from the Namaqua (Hondeklip) upwelling cell through offshore migration of chlorophyll filaments is stronger in summer, while the winter flux maximum seems to reflect mainly in situ production, with less influence from the coastal and shelf upwelling areas. On a yearly basis, dominant microorganisms correspond well with the flora and fauna of tropical/subtropical waters, with minor contribution of near-shore organisms. The simultaneous occurrence of species with different ecological affinities mirrors the fact that the mooring site was located in a transitional region with large hydrographic variability over short-time intervals.
CTCF modulates Estrogen Receptor function through specific chromatin and nuclear matrix interactions
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Enhancer regions and transcription start sites of estrogen-target regulated genes are connected by means of Estrogen Receptor long-range chromatin interactions. Yet, the complete molecular mechanisms controlling the transcriptional output of engaged enhancers and subsequent activation of coding genes remain elusive. Here, we report that CTCF binding to enhancer RNAs is enriched when breast cancer cells are stimulated with estrogen. CTCF binding to enhancer regions results in modulation of estrogen-induced gene transcription by preventing Estrogen Receptor chromatin binding and by hindering the formation of additional enhancer-promoter ER looping. Furthermore, the depletion of CTCF facilitates the expression of target genes associated with cell division and increases the rate of breast cancer cell proliferation. We have also uncovered a genomic network connecting loci enriched in cell cycle regulator genes to nuclear lamina that mediates the CTCF function. The nuclear lamina and chromatin interactions are regulated by estrogen-ER. We have observed that the chromatin loops formed when cells are treated with estrogen establish contacts with the nuclear lamina. Once there, the portion of CTCF associated with the nuclear lamina interacts with enhancer regions, limiting the formation of ER loops and the induction of genes present in the loop. Collectively, our results reveal an important, unanticipated interplay between CTCF and nuclear lamina to control the transcription of ER target genes, which has great implications in the rate of growth of breast cancer cells.
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L’obiettivo del seguente elaborato è fornire una proposta di traduzione in italiano di un estratto del romanzo in lingua tedesca “Ein Kind unserer Zeit” di Ödön von Horváth. Dopo una breve introduzione e l’inquadramento dell’autore e della sua opera, vi è una premessa alla traduzione in cui vengono descritti gli strumenti teorici utilizzati. Alla traduzione vera e propria segue un capitolo di commento, che analizza i passaggi più significativi e le soluzioni adoperate.
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Questa tesi si propone di fare luce sulla figura e sulle idee di Aleksandra Michajlovna Kollontaj (San Pietroburgo 1987 – Mosca 1952), attivista per i diritti delle donne, bolscevica e membro del partito comunista sovietico, nel quadro della storia dell’Unione Sovietica dal 1917 all’inizio degli anni ’30 del Novecento. Verrà presentato l’articolo "Novaja ženščina", in cui l’autrice delinea un modello per tutte le future cittadine sovietiche: la cosiddetta 'donna nuova', che rifiuta la 'schiavitù' del ruolo esclusivo di madre e moglie e afferma la propria libertà attraverso il lavoro e l’impegno sociale Si riprenderanno le vicende del romanzo della Kollontaj "Vasilisa Malygina". L’eroina che dà il titolo all’opera è la trasposizione letteraria della donna nuova e rappresenta le contraddizioni di una 'creatura di transizione' fra l’epoca prerivoluzionaria e quella sovietica. In seguito verranno messe il luce le contraddizioni nelle proposte della Kollontaj. Per ultimo verrà delineato un quadro delle libertà civili introdotte nella Russia degli anni ’20 e il successivo ritorno, con la salita al potere di Stalin, alla repressione delle libertà e a un rigido controllo statale su tutti gli ambiti della vita. Si sottolineerà come il corso della storia non permise alle idee proposte dalla Kollontaj di affermarsi nella quotidianità della vita sovietica.