335 research outputs found

    Evaluación del porcentaje de material núcleo en conductos radiculares obturados con puntas de gutapercha y de Real Seal de distintas conicidades

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    Objetivo. El objetivo del presente estudio fue evaluar el porcentaje de aterial núcleo en conductos radiculares de dientes monorradiculares obturados mediante compactación lateral y puntas de gutapercha o de Real Seal de conicidades 2% y 4% junto con un sellador. Material y métodos. Se emplearon 40 conductos de dientes maxilares anteriores. Se prepararon los conductos mediante rotación horaria continua hasta un calibre 30/.04. Se obturaron mediante compactación lateral en frío. Se formaron al azar cuatro grupos de diez especimenes cada uno: Grupo A (punta de gutapercha conicidad 2% y Topseal); Grupo B (punta de gutapercha conicidad 4% y Topseal); Grupo C (puntas de Real Seal conicidad 2% y su cemento); Grupo D (puntas de Real Seal conicidad 4% y su cemento). Transcurridas 48 horas se efectuaron cortes transversales de las raíces a 2, 4 y 6 mm del ápice. Se observaron mediante un estereomicroscopio, efectuando fotografías de cada corte, se digitalizaron y mediante un programa informático se evaluó el porcentaje que ocupaba el material núcleo respecto al área total de la sección del conducto. Resultados. No se observaron diferencias significativas entre todos los grupos, solo en las comparaciones de dos a dos en tres subgrupos. Conclusiones. Bajo las condiciones de nuestro estudio, no hallamos diferencias significativas en cuanto al porcentaje de material núcleo respecto al total del área de la sección de conductos radiculares obturados mediante puntas de gutapercha o Real Seal de conicidades 2% y 4%

    Fracturas proximales de fémur. Osteosíntesis con tornillo-placa deslizante versus clavo gamma

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    Presentamos un estudio retrospectivo de noventa fracturas del fémur proximal tratados con clavo GAMMA o tornillo-placa dinámico de cadera (DHS). No encontramos diferencias en la duración de la intervención, pérdida hemática, ni estancia hospitalaria. Sin embargo, la serie con clavo GAMMA inició el apoyo más temprano, aunque en la revisión al final del seguimiento no había diferencias significativas en cuanto a la función de la cadera. El fracaso de la síntesis ocurrió en cuatro casos con el DHS, pero las complicaciones intraoperatorias fueron más frecuentes con el clavo GAMMA, principalmente elevada incidencia de fracturas de la diáfisis femoral, asociado en parte al diseño del implante. Recomendamos el empleo del clavo GAMMA sólo para las fracturas inestables del fémur proximal.We report a prospective study of ninety fractures of proximal femur treated by either the GAMMA nail or the dynamic hip screw (DHS). We found no difference in operating time, blood loss or stay in the hospital. However, the GAMMA nail group had a earlier full weight-bearing, but there was no significant difference in hip function at final review. There was failure of proximal fixation in four cases with the DHS. More intra-operative complications were recorded in the GAMMA nail group, mainly a high incidence of femoral shaft fracture which we relate in part to the design of the implant. We only recommend the use of the GAMMA nail for unstable intertrochanteric fractures of the proximal femur

    Synthesis and photochromic behaviour of new methyl induced linear and angular thieno-2H-chromenes

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    New methyl induced linear and angular thieno-2H-chromenes 4, 5 and 6 were prepared by reaction of new methylated 6-hydroxybenzo[b]thiophenes 2 (a, b and c) and propargylic alcohols 3a and 3b, using acidic Alumina Brockmann I as catalyst and drying agent. Compounds 2 were prepared in good to excellent yields in a “one pot” three step reaction from the corresponding bromo compounds 1. The photochromic behaviour of compounds 4, 5 and 6b was evaluated with the aid of a classical set of spectrokinetic parameters, and compared to reference compounds that are benzoannellated in the 5,6 and 6,7 positions of the chromene (naphthopyrans) and also to thieno-2H-chromenes 7 and 8, previously prepared, which are analogues of 5a. The resistance to fatigue (photodegradation) under continuous irradiation was also evaluated.Fundação para a Ciência e Tecnologia. Escola Superior de Tecnologia e Gestão do Instituto Politécnico de Bragança

    Checklist for the Multidisciplinary Approach to United Airway in Patients with Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) and asthma

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    Dear Editor, The united airways concept calls for a multidisciplinary approach to asthma and/or chronic rhinitis/rhinosinusitis (CRS), aimed at integral airway treatment1, 2 and better coordination among specialists.3 Failure to treat rhinitis/rhinosinusitis is associated with poor asthma control, especially of severe asthma.4, 5 Biological treatments targeting type 2 (T2) inflammatory mediators in severe respiratory diseases offer a new therapeutic option directed against the pathophysiological mechanism of these difficult-to-control united airways diseases (UAD)..

    Can we identify individuals with an ALPL variant in adults with persistent hypophosphatasaemia?

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    Hypophosphatasia (HPP) is an inborn error of metabolism characterized by low levels of serum alkaline phosphatase (ALP). Scarce evidence exists about features that should signal the potential association between hypophosphatasaemia and HPP in adults. The aim of this study is to estimate the prevalence of ALPL variants in subjects with persistent hypophosphatasaemia and determine the associated clinical and laboratory features. For this cross-sectional study, laboratory records of 386,353 subjects were screened by measurement of ALP activity. A total of 85 (0.18%) subjects with persistent hypophosphatasaemia (≥2 serum alkaline phosphatase-ALP-measurements ≤35 IU/L and none > 45 IU/L) were included (secondary causes previously discarded). ALPL genetic testing and a systematized questionnaire to retrieve demographic, clinical and laboratory data were performed. Descriptive analysis and logistic regression models were employed to identify the clinical and laboratory characteristics associated with ALPL variants. Results: Forty subjects (47%) had a variant(s) in ALPL. With regard to clinical characteristics, the presence of an ALPL variant was significantly associated only with musculoskeletal pain (OR: 7.6; 95% IC: 1.9-30.9). Nevertheless, a trend to present more dental abnormalities (OR: 3.6; 95% IC: 0.9-13.4) was observed. Metatarsal stress fractures were also more frequent (4 vs 0; p < 0.05) in this group. Regarding laboratory features, median ALP levels were lower in subjects with ALPL variants (26 vs 29 IU/L; p < 0.005). Interestingly, the threshold of ALP levels < 25 IU/L showed a specificity, positive predictive value and positive likelihood ratio of 97.8, 94.4% and 19.8 to detect a positive ALPL test, respectively. Conclusions: In subjects with persistent hypophosphatasaemia -secondary causes excluded- one out of two presented ALPL variants. Musculoskeletal pain and ALP levels < 25 IU/L are associated with this variant(s). In this scenario, ALP levels < 25 IU/L seem to be very useful to identify individuals with the presence of an ALPL variantGenetic testing was supported by a grant from Alexion Pharmaceuticals Inc., which had no role in the study design or data analysi

    Risk of miscarriage after chorionic villus sampling.

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    OBJECTIVE: To estimate the risk of miscarriage associated to chorionic villus sampling (CVS). METHODS: This was a retrospective cohort study performed in eight fetal-medicine units in Spain, Belgium and Bulgaria. Two populations were included: first, all singleton pregnancies attending to their first-trimester assessment in Murcia, Spain, and second, all singleton pregnancies having a CVS following first-trimester assessment at any of the participating centers. We used propensity score matching analysis to estimate the association between CVS and miscarriage. We compared risks of miscarriage of CVS and non-CVS groups after propensity score matching (1:1 ratio). This procedure creates two comparable groups balancing the maternal and pregnancy characteristics that lead to CVS, in a similar way in which randomization operates in a randomized clinical trial. RESULTS: The study population consisted of 22,250 participants in the non-CVS group and 3,613 in the CVS group. The incidence of miscarriage in the CVS group was 2.1% (77/3,613), which was significantly higher than the 0.9% (207/22,250) in the non-CVS group (p <0.001). The propensity score algorithm matched 2,122 CVS cases with 2,122 non-CVS cases including 40 (1.9%) and 55 (2.6%) miscarriages in the CVS and non-CVS groups, respectively (OR 0.72 [95% CI 0.48 to 1.10]; p = 0.146). However, we found a significant interaction between the CVS risk of miscarriage and the risk of aneuploidies, suggesting a different effect of the CVS for different baseline characteristics in such a way that, when the risk of aneuploidies is low, the risk after CVS increases (OR 2.87 [95% CI 1.13 to 7.30]) but when the risk is high, the risk after CVS is paradoxically reduced (OR 0.47 [95% CI 0.28 to 0.76]), presumably due to prenatal diagnosis and termination of major aneuploidies that would have otherwise resulted in spontaneous miscarriage. CONCLUSIONS: The risk of miscarriage in women having a CVS is about 1% higher than in women without CVS, although this excess risk is not entirely due to the invasive procedure but to some extent the demographic and pregnancy characteristics of the patient undergoing CVS. After accounting for these risk factors and confining the analysis to low-risk pregnancies, CVS seems to increase the risk of miscarriage about three times above the patient's background-risk. Although this is a substantial increase in relative terms, in pregnancies without risk factors, the risk of miscarriage after CVS will still remain low and similar to or slightly higher than that of the general population. For example, if her risk of aneuploidy is 1 in a 1,000 (0.1%), her risk of miscarriage after CVS will increase to 0.3% (0.2% higher)

    Non-Full Sbox Linearization: Applications to Collision Attacks on Round-Reduced Keccak

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    The Keccak hash function is the winner of the SHA-3 competition and became the SHA-3 standard of NIST in 2015. In this paper, we focus on practical collision attacks against round-reduced Keccak hash function, and two main results are achieved: the first practical collision attacks against 5-round Keccak-224 and an instance of 6-round Keccak collision challenge. Both improve the number of practically attacked rounds by one. These results are obtained by carefully studying the algebraic properties of the nonlinear layer in the underlying permutation of Keccak and applying linearization to it. In particular, techniques for partially linearizing the output bits of the nonlinear layer are proposed, utilizing which attack complexities are reduced significantly from the previous best results

    Differential chloride homeostasis in the spinal dorsal horn locally shapes synaptic metaplasticity and modality-specific sensitization

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    Inhibition in spinal nociceptive pathways is weaker and more labile in lamina I —where thermal input is primarily processed— than in lamina II that encodes predominantly high threshold mechanical input. This explains why noxious thermal input makes spinal circuits prone to catastrophic sensitization

    Cryptanalysis of 1-Round KECCAK

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    In this paper, we give the first pre-image attack against 1- round KECCAK-512 hash function, which works for all variants of 1- round KECCAK. The attack gives a preimage of length less than 1024 bits by solving a system of 384 linear equations. We also give a collision attack against 1-round KECCAK using similar analysis
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