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21.
Dott. Alessandro Marcello 《Plant biosystems》2013,147(2):269-280
Riassunto Lo sviluppo del gametofito femminile di Campsis radicans (L.) Seem. (Bi-gnonaceae) è di tipo normale, monomegasporiale, otto-nucleato. Le cellule somatiche dell'ovulo durante lo sviluppo del gametofito e la loro trasformazione in tessuto nutritizio presentano particolari fenomeni interessanti non solo dal punto di vista morfologico, ma anche da quello microchimico. L'ispessimento attivo della membrana delle cellule dell'ipostasi è preceduto dall'acquisto di un intenso potere cromotropo e di un aspetto mucillaginoso : il passaggio delle sostanze pectiche della membrana cellulare da uno stato di inerzia ad uno di accrescimento coinciderebbe secondo ogni verosimiglianza con l'acquisto di radicali solforici da parte dei loro polisaccaridi. L'amido del gametofito adulto in via di degenerazione acquista un intenso potere cromatropo determinato dai prodotti della sua demolizione 相似文献
22.
Simone Accordini Angelo Guido Corsico Isa Cerveri Leonardo Antonicelli Francesco Attena Roberto Bono Lucio Casali Marcello Ferrari Alessandro Fois Pierpaolo Marchetti Pietro Pirina Roberta Tassinari Giuseppe Verlato Roberto de Marco 《Respiratory research》2013,14(1):16
Background
No study has been carried out on the time trend in the prevalence of chronic bronchitis (CB) in recent years, despite its clinical and epidemiological relevance. We evaluated the trend in CB prevalence during the past decade among young Italian adults.Methods
A screening questionnaire was mailed to general population samples of 20–44 year-old subjects in two cross-sectional surveys: the Italian Study on Asthma in Young Adults (ISAYA) (1998/2000; n = 18,873, 9 centres) and the screening stage of the Gene Environment Interactions in Respiratory Diseases (GEIRD) study (2007/2010; n = 10,494, 7 centres). CB was defined as having cough and phlegm on most days for a minimum of 3 months a year and for at least 2 successive years. The prevalence rates and the risk ratios (RRs) for the association between CB and each potential predictor were adjusted for gender, age, season of response, type of contact, cumulative response rate, and centre.Results
CB prevalence was 12.5% (95% CI: 12.1-12.9%) in 1998/2000 and 12.6% (95% CI: 11.7-13.7%) in 2007/2010; it increased among never smokers (from 7.6 to 9.1%, p = 0.003), current light smokers (<15 pack-years; from 15.1 to 18.6%, p < 0.001), and unemployed/retired subjects (from 14.3 to 19.1%, p = 0.001). In this decade, the prevalence of current smoking decreased (from 33.6 to 26.9%, p < 0.001), whereas the prevalence of unemployment/premature retirement (from 5.3 to 6.0%, p = 0.005), asthma (from 5.0 to 6.2%, p = 0.003), and allergic rhinitis (from 19.5 to 24.5%, p < 0.001) increased. In both 1998/2000 and 2007/2010, the likelihood of having CB was significantly higher for women, current smokers, asthmatic patients, and subjects with allergic rhinitis. During this period, the strength of the association between CB and current heavy smoking (≥15 pack-years) decreased (RR: from 4.82 to 3.57, p = 0.018), whereas it increased for unemployment/premature retirement (from 1.11 to 1.53, p = 0.019); no change was observed for gender, asthma, and allergic rhinitis.Conclusions
Despite the significant reduction in current smoking, CB prevalence did not vary among young Italian adults. The temporal pattern of CB prevalence can only be partly explained by the increase of unemployment/premature retirement, asthma and allergic rhinitis, and suggests that other factors could have played a role. 相似文献23.
Adelaide Greco Monica Ragucci Anna Rita Daniela Coda Alessandro Rosa Sara Gargiulo Raffaele Liuzzi Matteo Gramanzini Sandra Albanese Sabina Pappatà Marcello Mancini Arturo Brunetti Marco Salvatore 《PloS one》2013,8(10)
Background
Ultrasound is a valuable non-invasive tool used in obstetrics and gynecology to monitor the growth and well being of the human fetus. The laboratory mouse has recently emerged as an appropriate model for fetal and perinatal studies because morphogenetic processes in mice exhibit adequate homology to those in humans, and genetic manipulations are relatively simple to perform in mice. High-frequency ultrasound (HFUS) has recently become available for small animal preclinical imaging and can be used to study pregnancy and development in the mouse. The objective of the current study was to assess the main applications of HFUS in the evaluation of fetal growth and placental function and to better understand human congenital diseases.Methodology/Principal Findings
On each gestational day, at least 5 dams were monitored with HFUS; a total of ∼200 embryos were examined. Because it is not possible to measure each variable for the entire duration of the pregnancy, the parameters were divided into three groups as a function of the time at which they were measured. Univariate analysis of the relationship between each measurement and the embryonic day was performed using Spearman’s rank correlation (Rs). Continuous linear regression was adopted for multivariate analysis of significant parameters. All statistical tests were two-sided, and a p value of 0.05 was considered statistically significant.Conclusions/Significance
The study describes the main applications of HFUS to assess changes in phenotypic parameters in the developing CD1 mouse embryo and fetus during pregnancy and to evaluating physiological fetal and placental growth and the development of principal organs such as the heart, kidney, liver, brain and eyes in the embryonic mouse. A database of normal structural and functional parameters of mouse development will provide a useful tool for the better understanding of morphogenetic and cardiovascular anomalies in transgenic and mutant mouse models. 相似文献24.
Agathe Hess Lianchun Yu Isabelle Klein Marine De Mazancourt Gilles Jebrak Hervé Mal Olivier Brugière Michel Fournier Maurice Courbage Gaelle Dauriat Elisabeth Schouman-Clayes Christine Clerici Laurence Mangin 《PloS one》2013,8(10)
Breathing is maintained and controlled by a network of automatic neurons in the brainstem that generate respiratory rhythm and receive regulatory inputs. Breathing complexity therefore arises from respiratory central pattern generators modulated by peripheral and supra-spinal inputs. Very little is known on the brainstem neural substrates underlying breathing complexity in humans. We used both experimental and theoretical approaches to decipher these mechanisms in healthy humans and patients with chronic obstructive pulmonary disease (COPD). COPD is the most frequent chronic lung disease in the general population mainly due to tobacco smoke. In patients, airflow obstruction associated with hyperinflation and respiratory muscles weakness are key factors contributing to load-capacity imbalance and hence increased respiratory drive. Unexpectedly, we found that the patients breathed with a higher level of complexity during inspiration and expiration than controls. Using functional magnetic resonance imaging (fMRI), we scanned the brain of the participants to analyze the activity of two small regions involved in respiratory rhythmogenesis, the rostral ventro-lateral (VL) medulla (pre-Bötzinger complex) and the caudal VL pons (parafacial group). fMRI revealed in controls higher activity of the VL medulla suggesting active inspiration, while in patients higher activity of the VL pons suggesting active expiration. COPD patients reactivate the parafacial to sustain ventilation. These findings may be involved in the onset of respiratory failure when the neural network becomes overwhelmed by respiratory overload We show that central neural activity correlates with airflow complexity in healthy subjects and COPD patients, at rest and during inspiratory loading. We finally used a theoretical approach of respiratory rhythmogenesis that reproduces the kernel activity of neurons involved in the automatic breathing. The model reveals how a chaotic activity in neurons can contribute to chaos in airflow and reproduces key experimental fMRI findings. 相似文献
25.
During recent years, several studies have revealed that human-dog relationships are based on a well-established and complex bond. There is now evidence suggesting that the dog–human affectional bond can be characterized as an “attachment”. The present study investigated possible association between the owners'' attachment profile assessed throughout a new semi-projective test (the 9 Attachment Profile) and the owner-dog attachment bond evaluated using a modified version of those used in studying human infants: Ainsworth''s “strange situation”. The findings represented the first evidence for the presence of a correlation between the owners'' attachment profile and the owner-dog attachment bond throughout procedure and behavioural analyses involving controlled observations. 相似文献
26.
Polito Francesca Famà Fausto Oteri Rosaria Raffa Giovanni Vita Gianluca Conti Alfredo Daniele Sacco Macaione Vincenzo Passalacqua Marcello Cardali Salvatore Di Giorgio Rosa Maria Gioffrè Maria Angileri Flavio F. Germanò Antonino Aguennouz M’Hammed 《Molecular biology reports》2020,47(4):2941-2949
Molecular Biology Reports - TBI is the main cause of death and disability in individuals aged 1–45 in Western countries. One of the main challenges of TBI at present is the lack of specific... 相似文献
27.
Roger Fuoco Patrizia Bogani Gabriele Capodaglio Massimo Del Bubba Ornella Abollino Stefania Giannarelli Maria Michela Spiriti Beatrice Muscatello Saer Doumett Clara Turetta Roberta Zangrando Vincenzo Zelano Marcello Buiatti 《Journal of plant physiology》2013
Recently our findings have shown that the integration of the gene coding for the rat gluco-corticoid receptor (GR receptor) in Nicotiana langsdorffii plants induced morphophysiological effects in transgenic plants through the modification of their hormonal pattern. Phytohormones play a key role in plant responses to many different biotic and abiotic stresses since a modified hormonal profile up-regulates the activation of secondary metabolites involved in the response to stress. In this work transgenic GR plants and isogenic wild type genotypes were exposed to metal stress by treating them with 30 ppm cadmium(II) or 50 ppm chromium(VI). Hormonal patterns along with changes in key response related metabolites were then monitored and compared. Heavy metal up-take was found to be lower in the GR plants. The transgenic plants exhibited higher values of S-abscisic acid (S-ABA) and 3-indole acetic acid (IAA), salicylic acid and total polyphenols, chlorogenic acid and antiradical activity, compared to the untransformed wild type plants. Both Cd and Cr treatments led to an increase in hormone concentrations and secondary metabolites only in wild type plants. Analysis of the results suggests that the stress responses due to changes in the plant's hormonal system may derive from the interaction between the GR receptor and phytosteroids, which are known to play a key role in plant physiology and development. 相似文献
28.
Philippe Mayaux Jean-Fran?ois Pekel Baudouin Desclée Fran?ois Donnay Andrea Lupi Frédéric Achard Marco Clerici Catherine Bodart Andreas Brink Robert Nasi Alan Belward 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2013,368(1625)
This paper presents a map of Africa''s rainforests for 2005. Derived from moderate resolution imaging spectroradiometer data at a spatial resolution of 250 m and with an overall accuracy of 84%, this map provides new levels of spatial and thematic detail. The map is accompanied by measurements of deforestation between 1990, 2000 and 2010 for West Africa, Central Africa and Madagascar derived from a systematic sample of Landsat images—imagery from equivalent platforms is used to fill gaps in the Landsat record. Net deforestation is estimated at 0.28% yr−1 for the period 1990–2000 and 0.14% yr−1 for the period 2000–2010. West Africa and Madagascar exhibit a much higher deforestation rate than the Congo Basin, for example, three times higher for West Africa and nine times higher for Madagascar. Analysis of variance over the Congo Basin is then used to show that expanding agriculture and increasing fuelwood demands are key drivers of deforestation in the region, whereas well-controlled timber exploitation programmes have little or no direct influence on forest-cover reduction at present. Rural and urban population concentrations and fluxes are also identified as strong underlying causes of deforestation in this study. 相似文献
29.
Marcello?PiliaEmail author Teja?Guda Stefanie?M?Shiels Mark?R?Appleford 《Journal of biological engineering》2013,7(1):23
Background
The effects of microchannel diameter in hydroxyapatite (HAp) substrates on osteoblast behavior were investigated in this study. Microchannels of 100, 250 and 500 μm diameter were created on hydroxyapatite disks. The changes in osteoblast precursor growth, differentiation, extra cellular matrix (ECM) secretion and cell attachment/orientation were investigated as a function of microchannel diameter.Results
Curvature did not impact cellular differentiation, however organized cellular orientation was achieved within the 100 and 250 μm microchannels (mc) after 6 days compared to the 12 days it took for the 500mc group, while the flat substrate remained disorganized. Moreover, the 100, 250 and 500mc groups expressed a specific shift in orientation of 17.45°, 9.05°, and 22.86° respectively in 24 days. The secreted/mineralized ECM showed the 100 and 250mc groups to have higher modulus (E) and hardness (h) (E?=?42.6GPa; h?=?1.6GPa) than human bone (E?=?13.4-25.7GPa; h?=?0.47-0.74GPa), which was significantly greater than the 500mc and control groups (p?<?0.05). It was determined that substrate curvature affects the cell orientation, the time required for initial response, and the shift in orientation with time.Conclusions
These findings demonstrate the ability of osteoblasts to organize and mineralize differentially in microchannels similar to those found in the osteons of compact bone. These investigations could lead to the development of osteon-like scaffolds to support the regeneration of organized bone.30.