163 research outputs found
Hiatal herniation following total gastrectomy
The authors present a case of early hiatal hernia (HH), 30 days after surgery, that recurred a week after. Our purpose in this case report is to discuss briefly the potential cause and to enhance the importance of CT
Equivalences of Zt×Z22-cocyclic Hadamard matrices
One of the most promising structural approaches to resolving the
Hadamard Conjecture uses the family of cocyclic matrices over Zt × Z2
2.
Two types of equivalence relations for classifying cocyclic matrices over
Zt × Z2
2 have been found. Any cocyclic matrix equivalent by either of
these relations to a Hadamard matrix will also be Hadamard.
One type, based on algebraic relations between cocycles over any fi-
nite group, has been known for some time. Recently, and independently,
a second type, based on four geometric relations between diagrammatic
visualisations of cocyclic matrices over Zt × Z2
2, has been found. Here
we translate the algebraic equivalences to diagrammatic equivalences and
show one of the diagrammatic equivalences cannot be obtained this way.
This additional equivalence is shown to be the geometric translation of
matrix transposition
Introduction and evaluation of the ACS BCon basic course in Zaragoza, Spain
Background: The American College of Surgeons Bleeding Control Basic (BCon) course aimed at teaching hemorrhage control techniques in the USA had not yet been taught in Spain. The purpose of this study is to assess its implementation among students and healthcare employees in the Lozano Blesa University Hospital of Zaragoza, a middle-sized Spanish city.
Methods: The study was conducted in a University Hospital and at the University of Zaragoza, scheduling four free B-Con sessions from 2017 to 2018. Two groups were identified as forming the population: healthcare employees and medical students. An anonymous questionnaire was completed at the end of the course regarding content, applicability, usefulness, relevance, and satisfaction. Study variables were ranked from 0 to 10: poor (when graded from 0 to 3), fair (4 to 6) and good (7 to 10). Results were compared between the groups, expressed in percentages and ¿ 2 tested to analyze significant differences if any.
Results: Among the 83 individuals who completed the course, 46 were medical students and 37 healthcare employees; 61% women and 39% men; aged 21 years to 52 years. Attendees evaluated satisfaction with the highest grade (84%), followed by usefulness (73%), applicability (70%), and relevance (66%). There was no variable graded as poor. The comparison of perceptions between groups did not reveal statistical differences based on a 0.05 significance level.
Conclusion: We concluded that the B-Con course was valued as good for relevance, usefulness, applicability, and satisfaction by the majority of the studied population.
Level of Evidence: Level III
Endocrine morbidity in midline brain defects: Differences between septo-optic dysplasia and related disorders
Background
Septo-optic dysplasia (SOD) is a heterogeneous congenital condition. The aim of this study was to investigate the clinical phenotypes of a large cohort of children with SOD, Multiple Pituitary Hormone Deficiency (MPHD) and Optic Nerve Hypoplasia (ONH), with a focus on endocrine testing.
Methods
Retrospective single-centre longitudinal study of children with SOD (n:171), MPHD (n:53) and ONH (n:35). SOD+ and SOD- indicate patients with or without hypopituitarism, respectively.
Findings
All deficits were more frequent and occurred earlier in MPHD than SOD+ [Hazard Ratios (HR): 0·63(0·45,0·89) for GH, 0·48(0·34,0·69) for TSH, 0·55(0·38,0·80) for ACTH, 0·28(0·11,0·68) for gonadotropins], except Diabetes Insipidus (DI) [HR: 2·27(0·88,5·9)]. Severe hypothalamo-pituitary (H-P) abnormalities were more frequent in MPHD [80·0% vs 41·6%, p<0·0001 for Ectopic Posterior Pituitary (EPP)]. Stalk and PP abnormalities were associated with more severe endocrine phenotypes and placed a subgroup of SOD+ at risk of developing deficits earlier. SOD and ONH shared heterogeneous phenotypes ranging from pubertal delay to precocity and from leanness to extreme obesity, whilst MPHD had GnD and obesity only. Mortality was recorded in 4·2% (6/144) SOD and 3·2% (1/31) ONH, and only in patients with multisystem phenotypes.
Interpretation
More than a single disease, SOD represents a spectrum of malformative conditions involving different brain structures and characterised by a dynamic and sequential nature of endocrine. In contrast, MPHD displays a more homogeneous phenotype of (mainly) anterior pituitary early-onset failure. Stalk and PP abnormalities place a subgroup of SOD+ at a higher risk of early-onset deficits. Additionally, there are striking differences between the SOD and MPHD cohorts in terms of pubertal progression. The shared phenotypes between ONH and SOD could be partly explained by common hypothalamic dysfunction. The differences between the cohorts are important as they may aid in planning management and preventing morbidity by dictating earlier interventions
Macroevolutionary dynamics of nectar spurs, a key evolutionary innovation.
Floral nectar spurs are widely considered a key innovation promoting diversification in angiosperms by means of pollinator shifts. We investigated the macroevolutionary dynamics of nectar spurs in the tribe Antirrhineae (Plantaginaceae), which contains 29 genera and 300-400 species (70-80% spurred). The effect of nectar spurs on diversification was tested, with special focus on Linaria, the genus with the highest number of species. We generated the most comprehensive phylogeny of Antirrhineae to date and reconstructed the evolution of nectar spurs. Diversification rate heterogeneity was investigated using trait-dependent and trait-independent methods, and accounting for taxonomic uncertainty. The association between changes in spur length and speciation was examined within Linaria using model testing and ancestral state reconstructions. We inferred four independent acquisitions of nectar spurs. Diversification analyses revealed that nectar spurs are loosely associated with increased diversification rates. Detected rate shifts were delayed by 5-15 Myr with respect to the acquisition of the trait. Active evolution of spur length, fitting a speciational model, was inferred in Linaria, which is consistent with a scenario of pollinator shifts driving diversification. Nectar spurs played a role in diversification of the Antirrhineae, but diversification dynamics can only be fully explained by the complex interaction of multiple biotic and abiotic factors.This work was supported by the Marie Curie Intra-European Fellowship LINARIA-SPECIATION (FP7-PEOPLE-2013-IEF, reference 624396), an Isaac Newton Trust Research Grant (Trinity College, Cambridge), a Juan de la Cierva fellowship to M.F.-M. (Spanish Ministry of Economy and Competitivity, reference IJCI-2015-23459) and a Generalitat Valenciana postdoctoral grant to A.J. (Ministry of Education, Culture and Sport, reference BEST/2014/264)
Sensing the turbulent large-scale motions with their wall signature
This study assesses the capability of extended proper orthogonal decomposition (EPOD) and convolutional neural networks (CNNs) to reconstruct large-scale and very-large-scale motions (LSMs and VLSMs respectively) employing wall-shear-stress measurements in wall-bounded turbulent flows. Both techniques are used to reconstruct the instantaneous LSM evolution in the flow field as a combination of proper orthogonal decomposition (POD) modes, employing a limited set of instantaneous wall-shear-stress measurements. Due to the dominance of nonlinear effects, only CNNs provide satisfying results. Being able to account for nonlinearities in the flow, CNNs are shown to perform significantly better than EPOD in terms of both instantaneous flow-field estimation and turbulent-statistics reconstruction. CNNs are able to provide a more effective reconstruction performance employing more POD modes at larger distances from the wall and employing lower wall-measurement resolutions. Furthermore, the capability of tackling nonlinear features of CNNs results in estimation capabilities that are weakly dependent on the distance from the wall.This work has been partially supported by Grant No. DPI2016-79401-R funded by the Spanish State Research Agency (SRA) and the European Regional Development Fund (ERDF). A.G. acknowledges Dr. A. Sánchez for insightful discussions about CNN architecture. The authors acknowledge Dr. R. Vinuesa for insightful comments and discussions
Noninvasive assessment of an engineered bioactive graft in myocardial infarction: impact on cardiac function and scar healing
Cardiac tissue engineering, which combines cells and biomaterials, is promising for limiting the sequelae of myocardial infarction (MI). We assessed myocardial function and scar evolution after implanting an engineered bioactive impedance graft (EBIG) in a swine MI model. The EBIG comprises a scaffold of decellularized human pericardium, green fluorescent protein-labeled porcine adipose tissue-derived progenitor cells (pATPCs), and a customized-design electrical impedance spectroscopy
(EIS) monitoring system. Cardiac function was evaluated noninvasively by using magnetic resonance imaging (MRI). Scar healing was evaluated by using the EIS system within the implanted graft. Additionally, infarct size, fibrosis, and inflammation were explored by histopathology. Upon sacrifice 1 month after the intervention, MRI detected a significant improvement in left ventricular ejection fraction (7.5%64.9% vs. 1.4%63.7%; p = .038) and stroke volume (11.565.9 ml vs. 364.5 ml; p = .019) in EBIG-treated animals. Noninvasive EIS data analysis showed differences in both impedance magnitude ratio (20.02 6 0.04 per day vs. 20.48 6 0.07 per day; p = .002) and phase angle slope (20.18°60.24° per day vs.23.52°60.84° per day; p = .004) in EBIG compared with control animals. Moreover, in EBIG-treated animals, the infarct size was 48% smaller (3.4%60.6% vs. 6.5%61%; p = .015), less inflammation was found by means of CD25+ lymphocytes (0.65 6 0.12 vs. 1.26 6 0.2; p = .006), and a lower collagen I/III ratio was detected (0.4960.06 vs. 1.6660.5; p = .019). An EBIG composed of acellular pericardium refilled with pATPCs significantly reduced infarct size and improved cardiac function in a preclinical model of MI. Noninvasive EIS monitoring was useful for tracking differential scar healing in EBIG-treated animals, which was confirmed by less inflammation and altered collagen deposit.Peer ReviewedPostprint (published version
Liver tissue remodeling following ablation with irreversible electroporation in a porcine model
Irreversible electroporation (IRE) is a method of non-thermal focal tissue ablation characterized by irreversibly permeabilizing the cell membranes while preserving the extracellular matrix. This study aimed to investigate tissue remodeling after IRE in a porcine model, especially focusing on the extracellular matrix and hepatic stellate cells. IRE ablation was performed on 11 female pigs at 2,000 V/cm electric field strength using a versatile high-voltage generator and 3 cm diameter parallel-plate electrodes. The treated lobes were removed during surgery at 1, 3, 7, 14, and 21 days after IRE. Tissue remodeling and regeneration were assessed by histopathology and immunohistochemistry. Throughout the treated area, IRE led to extensive necrosis with intact collagenous structures evident until day 1. From then on, the necrosis progressively diminished while reparative tissue gradually increased. During this process, the reticulin framework and the septal fibrillar collagen remained in the necrotic foci until they were invaded by the reparative tissue. The reparative tissue was characterized by a massive proliferation of myofibroblast-like cells accompanied by a complete disorganization of the extracellular matrix with the disappearance of hepatic architecture. Hepatic stellate cell markers were associated with the proliferation of myofibroblast-like cells and the reorganization of the extracellular matrix. Between 2 and 3 weeks after IRE, the lobular architecture was almost completely regenerated. The events described in the present study show that IRE may be a valid model to study the mechanisms underlying liver regeneration after extensive acute injury
- …