161 research outputs found
Análisis del daño en componentes hÃbridos CFRPs/Ti debido a mecanizado durante el comportamiento en servicio de uniones estructurales aeronáuticas
[ES] En el sector aeronáutico, se encuentra bastante extendida la aplicación de los componentes hÃbridos del tipo Carbon Fiber Reinforced Polymers / Titanio. Este tipo de material se emplea, por ejemplo, en revestimientos de determinadas secciones del fuselaje de un avión. Los materiales compuestos ofrecen prestaciones de resistencia y rigidez especÃficas que los convierten en materiales ideales en diversas aplicaciones industriales, especialmente en la aeronáutica pero es necesario considerar sus potenciales causas de fallo como son la delaminación.
Una de las problemáticas actuales que presentan este tipo de materiales es la unión con otros componentes estructurales. Es frecuente el empleo de adhesivos y remaches. Cuando se trata de uniones remachadas, es fundamental controlar el sucesivo empleo de una misma broca de taladrado para evitar la introducción de daño en el material. El compromiso con la seguridad obliga en muchas ocasiones a desechar una broca tras un número determinado de usos con el objeto de minimizar la introducción de defectos en el agujero que favorezcan la aparición de delaminación en el material.
El objeto de este trabajo es analizar por elementos finitos el daño y progresión del fallo en stacks de CFRPs/Ti taladrados. Para ello se realizará un estudio que permita estimar el alcance de la presencia de defectos iniciales en el comportamiento en servicio del material. Para ello se aplicarán criterios de fallo interactivos para detectar la iniciación del fallo y técnicas numéricas para cuantificar el avance del daño. Asimismo, se analizará la influencia de parámetros como la secuencia de apilado y espesor de láminas para determinar el alcance del denominado efecto de borde.Borrego MartÃnez, A. (2020). Análisis del daño en componentes hÃbridos CFRPs/Ti debido a mecanizado durante el comportamiento en servicio de uniones estructurales aeronáuticas. Universitat Politècnica de València. http://hdl.handle.net/10251/149036TFG
Association between Birth Plan Use and Maternal and Neonatal Outcomes in Southern Spain: A Case-Control Study
Background: Birth plans are used for pregnant women to express their wishes and expectations about childbirth. The aim of this study was to compare obstetric and neonatal outcomes between women with and without birth plans. Methods: A multicentre, retrospective case–control study at tertiary hospitals in southern Spain between 2009 and 2013 was conducted. A total of 457 pregnant women were included, 178 with and 279 without birth plans. Women with low-risk gestation, at full-term and having been in labour were included. Sociodemographic, obstetric and neonatal variables were analysed and comparisons were established. Results: Women with birth plans were older, more educated and more commonly primiparous. Caesarean sections were less common in primiparous women with birth plans (18% vs. 29%, p = 0.027); however, no significant differences were found in instrumented births, 3rd–4th-degree tears or episiotomy rates. Newborns of primiparous women with birth plans obtained better results on 1 min Apgar scores, umbilical cord pH and advanced neonatal resuscitation. No significant differences were found on 5 min Apgar scores or other variables for multiparous women. Conclusions: Birth plans were related to less intervention, a more natural process of birth and better outcomes for mothers and newborns. Birth plans can improve the welfare of the mother and newborn, leading to birth in a more natural way
Conformable nanowire-in-nanofiber hybrids for low-threshold optical gain in the ultraviolet
The miniaturization of diagnostic devices that exploit optical detection
schemes requires the design of light-sources combining small size, high
performance for effective excitation of chromophores, and mechanical
flexibility for easy coupling to components with complex and non-planar shapes.
Here, ZnO nanowire-in-fiber hybrids with internal architectural order are
introduced, exhibiting a combination of polarized stimulated emission, low
propagation losses of light modes, and structural flexibility. Ultrafast
transient absorption experiments on the electrospun material show optical gain
which gives rise to amplified spontaneous emission, with threshold lower than
the value found in films. These systems are highly flexible and can
conveniently conform to curved surfaces, which makes them appealing active
elements for various device platforms, such as bendable lasers, optical
networks and sensors, as well as for application in bioimaging,
photo-crosslinking, and optogenetics.Comment: 50 pages, 17 figures, 1 table, ACS Nano, 202
Genetic control of renal tumorigenesis by the mouse Rtm1 locus
BACKGROUND: The genetic basis of susceptibility to renal tumorigenesis has not yet been established in mouse strains. Mouse lines derived by bidirectional phenotypic selection on the basis of their maximal (AIRmax) or minimal (AIRmin) acute inflammatory responsiveness differ widely in susceptibility to spontaneous and urethane-induced renal tumorigenesis. To map the functional loci modulating renal tumor susceptibility in these mice, we carried out a genome-wide genetic linkage study, using SNP arrays, in an (AIRmax x AIRmin)F2 intercross population treated with a single urethane dose at 1 week of age and phenotyped for renal tumors at 35 weeks of age. RESULTS: AIRmax mice did not develop renal tumors spontaneously nor in response to urethane, whereas in AIRmin mice renal tumors formed spontaneously (in 52% of animals) and after urethane induction (89%). The tumors had a papillary morphology and were positive for alpha-methylacyl-CoA racemase and negative for CD10. By analysis of 879 informative SNPs in 662 mice, we mapped a single quantitative trait locus modulating the incidence of renal tumors in the (AIRmax x AIRmin)F2 intercross population. This locus, which we named Renal tumor modifier QTL 1 (Rtm1), mapped to chromosome 17 at 23.4 Mb (LOD score = 15.8), with SNPs rs3696835 and rs3719497 flanking the LOD score peak. The A allele of rs3719497 from AIRmin mice was associated with a 2.5-fold increased odds ratio for renal tumor development. The LOD score peak included the Tuberous sclerosis 2 (Tsc2) gene which has already been implicated in kidney disease: loss of function by germline retroviral insertion is associated with spontaneous renal tumorigenesis in the Eker rat, and heterozygous-null Tsc2((+/-)) mice develop renal cystadenomas. CONCLUSIONS: We mapped Rtm1 as a single major locus modulating renal tumorigenesis in a murine intercross population. Thus, the AIR mouse lines can be considered a new genetic model for studying the role of germline and somatic molecular alterations in kidney neoplastic disease
Prevalence and Mode of Birth in Late Fetal Mortality in Spain, 2016–2019
Background: The rate of cesarean sections in late fetal mortality remains high. We aimed to determine the prevalence of late fetal mortality in Spain and risk factors for cesarean birth in women with stillbirth ≥ 28 weeks gestation between 2016–2019. (2) Methods: A retrospective observational study with national data between 2016–2019. A total of 3504 births with fetal dead were included. Sociodemographic, obstetrical and neonatal variables were analyzed using univariate and multivariate logistic regression (MLR), with cesarean birth with a stillborn ≥ 28 weeks gestation as the dependent variable. (3) Results: The late fetal mortality rate was 2.8 × 1000; 22.7% of births were by cesarean section. Factors associated with cesarean were having a multiple birth (aOR 6.78); stillbirth weight (aOR 2.41); birth taking place in towns with over 50,000 inhabitants (aOR 1.34); and mother’s age ≥ 35 (aOR 1.23). (4) Conclusions: The late fetal mortality rate increased during the period. The performance of cesarean sections was associated with the mother’s age, obstetric factors and place of birth. Our findings encourage reflection on how to best put into practice national clinical and socio-educational prevention strategies, as well as the approved protocols on how childbirth should be correctly conducted
Report 4: The Dissemination Potential of a European Network
The report that follows represents an extraordinary and unique exchange of information. Unfolding
here are the capabilities for dissemination and exploitation in the EU-funded Thematic Network
‘Dietitians Implementing Education and Training Standards’ in Europe (DIETS).
At the beginning of the Network there were 112 Partners and about 500 registered users of the
DIETS website, but over a three-year period this has increased to 123 Partners and well over 1000
users.
The activity of these Partners and their determination to publicise the Network and, more
importantly, the role of the dietitian, has been immense and sometimes difficult to capture.
However, captured in this report are the learning and change to practice that has resulted, as well
as closer engagement between HEIs and their dietetic departments across Europe. Some of the
good practice described here will be of value to others starting this type of journey.
This network of HEIs, their dietetic colleagues and others will endure long after the DIETS Network
has finished its work, largely due to the enthusiasm of the Partners and the social network that has
been built and embedded. The ultimate benefit to dietitians, through education, lifelong learning
and their contribution to nutritional health in Europe will continue to unfold
Report 1: building a technologically informed information and communication network in europe
This report represents an extraordinary and unique exchange of information across Europe through the creation of a website and learning how to use technology more effectively. Over the three-year period the capabilities conducted as part the EU funded Thematic Network „Dietitians Implementing Education and Training Standards‟ in Europe (DIETS) are presented here. The number of users registered to access the intranet (password-protected) section of the website grew rapidly from 0 at launch to 965 by the end of the third year.
A great deal of learning and change to practice has resulted as well as closer engagement between HEIs and their dietetic departments across Europe. This Network of HEIs and their dietetic colleagues will endure long after the DIETS Network has finished its work, largely due to the enhanced ITC capabilities. The ultimate benefit to the dietetic profession, their education and lifelong learning and their contribution to nutritional health in Europe will continue to unfol
Factors Associated with Postpartum Sexual Dysfunction in Spanish Women: A Cross-Sectional Study
(1) Background: Female sexual dysfunction (FSD) has a high prevalence globally, and perinatal factors favor FSD, especially in the postpartum period. The aim was to determine the prevalence and factors influencing FSD in the postpartum period; (2) Methods: An observational study carried out in three primary care centers in southern Spain, with women in the postpartum period who had a single low-risk birth. One hundred and seventeen women answered the Female Sexual Function questionnaire during the 4th month postpartum, between January 2020 and December 2021. Sociodemographic, obstetric, neonatal variables and level of self-esteem were analyzed. A multiple logistic regression model was carried out; (3) Results: 78.4% had high level of self-esteem. FSD prevalence was 89.7%. Factors related to FSD were having an instrumental vaginal delivery, women with university studies, and prenatal preparation. Maternal age ≥ 35, multiparity, pathological processes in the child, a medium–low level of self-esteem and newborn weight were associated with disorders in some of domains of sexual function; (4) Conclusions: FSD is highly prevalent in the postpartum period and is associated with preventable factors. A preventive approach by health professionals to these factors is essential. Health services should implement postpartum follow-up programs, which may coincide in time and place with newborn follow-up programs
Crystal Structure of the C-type Lectin-like Domain from the Human Hematopoietic Cell Receptor CD69
CD69, one of the earliest specific antigens acquired during lymphoid activation, acts as a signal-transducing receptor involved in cellular activation events, including proliferation and induction of specific genes. CD69 belongs to a family of receptors that modulate the immune response and whose genes are clustered in the natural killer (NK) gene complex. The extracellular portion of these receptors represent a subfamily of C-type lectin-like domains (CTLDs), which are divergent from true C-type lectins and are referred to as NK-cell domains (NKDs). We have determined the three-dimensional structure of human CD69 NKD in two different crystal forms. CD69 NKD adopts the canonical CTLD fold but lacks the features involved in Ca(2+) and carbohydrate binding by C-type lectins. CD69 NKD dimerizes noncovalently, both in solution and in crystalline state. The dimer interface consists of a hydrophobic, loosely packed core, surrounded by polar interactions, including an interdomain beta sheet. The intersubunit core shows certain structural plasticity that may facilitate conformational rearrangements for binding to ligands. The surface equivalent to the binding site of other members of the CTLD superfamily reveals a hydrophobic patch surrounded by conserved charged residues that probably constitutes the CD69 ligand-binding site.Fil: Llera, Andrea Sabina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones BioquÃmicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones BioquÃmicas de Buenos Aires; ArgentinaFil: Viedma, Fernando. Universidad Autónoma de Madrid; EspañaFil: Sánchez Madrid, Francisco. Universidad Autónoma de Madrid; EspañaFil: Tormo, José. Universidad Autónoma de Madrid; Españ
F-Actin nucleated on chromosomes coordinates their capture by microtubules in oocyte meiosis.
Capture of each and every chromosome by spindle microtubules is essential to prevent chromosome loss and aneuploidy. In somatic cells, astral microtubules search and capture chromosomes forming lateral attachments to kinetochores. However, this mechanism alone is insufficient in large oocytes. We have previously shown that a contractile F-actin network is additionally required to collect chromosomes scattered in the 70-µm starfish oocyte nucleus. How this F-actin-driven mechanism is coordinated with microtubule capture remained unknown. Here, we show that after nuclear envelope breakdown Arp2/3-nucleated F-actin "patches" form around chromosomes in a Ran-GTP-dependent manner, and we propose that these structures sterically block kinetochore-microtubule attachments. Once F-actin-driven chromosome transport is complete, coordinated disassembly of F-actin patches allows synchronous capture by microtubules. Our observations indicate that this coordination is necessary because early capture of chromosomes by microtubules would interfere with F-actin-driven transport leading to chromosome loss and formation of aneuploid eggs
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