687 research outputs found
Graphene oxide affects in vitro fertilization outcome by interacting with sperm membrane in an animal model
We realized the exposure of boar spermatozoa to graphene oxide (GO) at concentration of 0.5, 1, 5, 10 and 50 μg/mL in an in vitro system able to promote the capacitation, i.e. the process that allows sperm cells to became fertile. Interestingly, we found that the highest GO concentration (5, 10 and 50 μg/mL) are toxic for spermatozoa, while the lowest ones (0.5 and 1 μg/mL) seem to significantly increase the sperm cells fertilizing ability (p >.05) in an in vitro fertilization experiment. To explain this finding, we investigated the effect of GO on sperm membrane structure (atomic force microscopy) and function (confocal microscopy and flow cytometry, substrate adhesion). As a result, we found that GO is able to interact with spermatozoa membranes and, in particular, it seems to be able to extract the cholesterol, which is a key player in spermatozoa physiology, from plasma membrane of boar spermatozoa incubated under capacitation conditions. In our opinion, these results are very important because they allow identifying either a plausible mechanism of GO toxicity on spermatozoa and new strategies to manage sperm capacitation
Leptoproduction of neutrino pairs in the nuclear coulomb field
20 páginas, 6 figuras, 2 tablas.-- PACS. 13.60. - Photon and charged-lepton interactions with hadrons.[EN] The cross-section for production of v-V pairs by highenergy
leptons in the nuclear Coulomb field is calculated in the standard
theory, allowing for arbitrary polarization of the incoming lepton beam.
The differential distributions of the outgoing charged lepton are studied,
showing that the scattered lepton peaks at low energies and emerges at
appreciable angles. Incoherent contributions to the cross-section are
also discussed.[IT] Si calcola la sezione d'urto per la produzione di coppie v-V per leptoni ad alta energia
nel campo nucleare di Coulomb nella teoria standard, tenendo conto della polarizzazione
arbitraria nel fascio leptonico incidente. Si studiano le distribuzioni differenziali
del leptone canco uscente, mostrando che il leptone diffuso forma un picco ad alta energia
ed emerge per angoli di un'ampiezza notevole. Si discutono anche i contributi incoerenti
alla sezione d'urto.This work has been supported in part by Comisión Asesora de Investigación
Científica y Técnica, Spain. One of us (AP) acknowledges Caja de Ahorros de
Valencia for a fellowship.Peer reviewe
Social participation and tooth loss, vision, and hearing impairments among older Brazilian adults
BACKGROUND: Vision and hearing impairments can reduce participation in social activities. Given the prominent role of the mouth in face-to-face interactions, this study evaluated the associations of tooth loss, vision, and hearing impairments with social participation among older adults. METHODS: This analysis included 1947 participants, aged 60+ years, who participated in three waves (2006, 2010, and 2015) of the Health, Wellbeing and Aging Study (SABE) in Brazil. Social participation was measured by the number of formal and informal social activities (requiring face-to-face interaction) participants were regularly involved in. Teeth were counted during clinical examinations and categorized as 0, 1–19, and 20+ teeth. Reports on vision and hearing impairments were classified into three categories (good, regular, and poor). The associations of each impairment with the 9-year change in the social participation score were tested in negative binomial mixed-effects models adjusting for time-variant and time-invariant covariates. RESULTS: Each impairment was associated with the baseline social participation score and the annual rate of change in the social participation score. Participants with 1–19 (incidence rate ratio: 0.96, 95% CI: 0.91–1.01) and no teeth (0.92, 95% CI: 0.87–0.97), those with regular (0.98, 95% CI: 0.95–1.01) and poor vision (0.86, 95% CI: 0.81–0.90), and those with regular (0.94, 95% CI: 0.91–0.98) and poor hearing (0.91, 95% CI: 0.87–0.95) had lower baseline social participation scores than those with 20+ teeth, good vision, and good hearing, respectively. Furthermore, participants with 1–19 (0.996, 95% CI: 0.990–1.002) and no teeth (0.994, 95% CI: 0.987–0.999), those with regular (0.996, 95% CI: 0.992–0.999) and poor vision (0.997, 95% CI: 0.991–1.003), and those with regular (0.997, 95% CI: 0.992–1.001) and poor hearing (0.995, 95% CI: 0.990–0.999) had greater annual declines in the social participation score than those with 20+ teeth, good vision and good hearing, respectively. CONCLUSION: This 9-year longitudinal study shows that tooth loss, vision, and hearing impairments are associated with reduced social participation among older adults
The beginning of the Neolithic era in Central Italy
This paper presents the general profile of the first farming communities of Central Italy in the Early Neolithic Era. Data shows the spread of early Neolithic cultures in the Italian peninsula at the beginning of the VI millennium B.C. The first Neolithic groups appeared in the southern regions of the peninsula and moved northwards following two trajectories along the Tyrrhenian and Adriatic coasts. The process of Neolithisation was initiated by peoples who probably came from different areas and traditions creating, over time, two distinct areas within the Italian peninsula, each with its own specific cultural features. Finally the article looks at how intensive exchanges both of complex knowledge and raw materials occurred between these two distinct cultural worlds
Efficient Cas9 multiplex editing using unspaced sgRNA arrays engineering in a Potato virus X vector
[EN] Systems based on the clustered, regularly interspaced, short palindromic repeat (CRISPR) and CRISPR-associated proteins (Cas) have revolutionized genome editing in many organisms, including plants. Most CRISPR-Cas strategies in plants rely on genetic transformation using Agrobacterium tumefaciens to supply the gene editing reagents, such as Cas nucleases or the synthetic guide RNA (sgRNA). While Cas nucleases are constant elements in editing approaches, sgRNAs are target-specific and a screening process is usually required to identify those most effective. Plant virus-derived vectors are an alternative for the fast and efficient delivery of sgRNAs into adult plants, due to the virus capacity for genome amplification and systemic movement, a strategy known as virus-induced genome editing. We engineered Potato virus X (PVX) to build a vector that easily expresses multiple sgRNAs in adult solanaceous plants. Using the PVX-based vector, Nicotiana benthamiana genes were efficiently targeted, producing nearly 80% indels in a transformed line that constitutively expresses Streptococcus pyogenes Cas9. Interestingly, results showed that the PVX vector allows expression of arrays of unspaced sgRNAs, achieving highly efficient multiplex editing in a few days in adult plant tissues. Moreover, virus-free edited progeny can be obtained from plants regenerated from infected tissues or infected plant seeds, which exhibit a high rate of heritable biallelic mutations. In conclusion, this new PVX vector allows easy, fast and efficient expression of sgRNA arrays for multiplex CRISPR-Cas genome editing and will be a useful tool for functional gene analysis and precision breeding across diverse plant species, particularly in Solanaceae crops.This work was supported by grants BIO2017-83184-R and PID2019-108203RB-I00 from Ministerio de Ciencia e Innovacion (Spain) through the Agencia Estatal de Investigacion (co-financed European Regional Development Fund), and H2020-760331 Newcotiana from the European Commission. M.U. and S.S. are the recipients of fellowships FPU17/05503 and BES-2017-0890098, respectively, from Ministerio de Ciencia e Innovacion (Spain)Uranga-Ruiz De Eguino, M.; Aragones, V.; Selma García, S.; Vázquez-Vilar, M.; Orzáez Calatayud, DV.; Daròs, J. (2021). Efficient Cas9 multiplex editing using unspaced sgRNA arrays engineering in a Potato virus X vector. The Plant Journal. 106(2):555-565. https://doi.org/10.1111/tpj.15164555565106
Use of gonadotropins in ovarian stimulation in Spain: Delphi consensus
Ovarian stimulation; In vitro fertilisation; Poor responderEstimulació ovàrica; Fecundació in vitro; Resposta pobreEstimulación ovárica; Fecundación in vitro; Respuesta pobreTwo-round Delphi study carried out in Spain. Three theme-based blocks were set out: 1) Patient profiles: therapeutic goal and parameters to be analysed according to POSEIDON patient profiles; 2) Ovarian stimulation protocols with antagonists: monotherapy (FSH) vs combined therapy (FSH + LH/HMG); 3) Safety and effectiveness of the devices. The antral follicle count and the anti-Müllerian hormone level were considered indicators that can be used to predict ovarian response. More than 80% of the participants agreed that FSH monotherapy is the recommended regimen in normal/hyper-responsive patients of < 35 years of age; that 150–300 IU is the dose to be used in ovarian stimulation in monotherapy depending on clinical parameters; and that FSH monotherapy improves patients’ comfort compared to two combined drugs. It was unanimously considered that the type of device used by the patient influences the comfort of the treatment.This project has been funded by Gedeon Richter. The sponsor took no part in designing, implementing, interpreting or writing the document. All the authors have accepted the participation in the group and give their consent for the publication of the document
Measurement of the neutron electric dipole moment via spin rotation in a non-centrosymmetric crystal
We have measured the neutron electric dipole moment using spin rotation in a
non-centrosymmetric crystal. Our result is d_n = (2.5 +- 6.5(stat) +-
5.5(syst)) 10^{-24} e cm. The dominating contribution to the systematic
uncertainty is statistical in nature and will reduce with improved statistics.
The statistical sensitivity can be increased to 2 10^{-26} e cm in 100 days
data taking with an improved setup. We state technical requirements for a
systematic uncertainty at the same level.Comment: submitted to Phys. Lett.
A Water-Soluble Polysaccharide from the Fruit Bodies of Bulgaria inquinans (Fries) and Its Anti-Malarial Activity
A water-soluble polysaccharide (BIWS-4b) was purified from the fruit bodies of Bulgaria inquinans (Fries). It is composed of mannose (27.2%), glucose (15.5%) and galactose (57.3%). Its molecular weight was estimated to be 7.4 kDa (polydispersity index, Mw/Mn: 1.35). Structural analyses indicated that BIWS-4b mainly contains (1 → 6)-linked, (1 → 5)-linked and (1 → 5,6)-linked β-Galf units; (1 → 4)-linked and non-reducing terminal β-Glcp units; and (1 → 2)-linked, (1 → 6)-linked, (1 → 2,6)-linked and non-reducing terminal α-Manp units. When examined by the 4-day method and in a prophylactic assay in mice, BIWS-4b exhibited markedly suppressive activity against malaria while enhancing the activity of artesunate. Immunological tests indicated that BIWS-4b significantly enhanced macrophage phagocytosis and splenic lymphocyte proliferation in malaria-bearing mice and normal mice. The anti-malarial activity of BIWS-4b might be intermediated by enhancing immune competence and restoring artesunate-suppressed immune function. Thus, BIWS-4b is a potential adjuvant of anti-malaria drugs
Memristance can explain Spike-Time-Dependent-Plasticity in Neural Synapses
Interdisciplinary research broadens the view of particular problems yielding fresh and possibly unexpected insights. This is the case of neuromorphic engineering where technology and neuroscience cross-fertilize each other. For example, consider on one side the recently discovered memristor, postulated in 1974, thanks to research in nanotechnology electronics. On the other side, consider the mechanism known as Spike-Time-Dependent-Plasticity (STDP) which describes a neuronal synaptic learning mechanism that outperforms the traditional Hebbian synaptic plasticity proposed in 1949. STDP was originally postulated as a computer learning algorithm, and is being used by the machine intelligence and computational neuroscience community. At the same time its biological and physiological foundations have been reasonably well established during the past decade. If memristance and STDP can be related, then (a) recent discoveries in nanophysics and nanoelectronic principles may shed new lights into understanding the intricate molecular and physiological mechanisms behind STDP in neuroscience, and (b) new neuromorphic-like computers built out of nanotechnology memristive devices could incorporate the biological STDP mechanisms yielding a new generation of self-adaptive ultra-high-dense intelligent machines. Here we show that by combining memristance models with the electrical wave signals of neural impulses (spikes) converging from pre- and post-synaptic neurons into a synaptic junction, STDP behavior emerges naturally. This result serves to understand how neural and memristance parameters modulate STDP, which might bring new insights to neurophysiologists in searching for the ultimate physiological mechanisms responsible for STDP in biological synapses. At the same time, this result also provides a direct mean to incorporate STDP learning mechanisms into a new generation of nanotechnology computers employing memristors
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