1,283 research outputs found
Exploring manufacturing process and degradation products of gilt and painted leather
In this work, we studied the manufacturing processes and the conservation state of gilt and painted leather fragments from Palazzo Chigi in Ariccia (Italy) by using different analytical techniques. Leather fragments present a silver leaf superimposed onto leather support. A gold varnish and different painted layers decorate it all. A top-down analytical approach was used to investigate this complex multilayer structure, which adopted techniques with different sampling depths. Organic and inorganic constitutive materials together with related degradation products were studied by time of flight secondary ion mass spectrometry (ToF-SIMS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and macro X-ray fluorescence (MA-XRF). The findings have revealed the presence of different elements and species as calcium and iron in the leather support, which was attributed to the un-hairing process in the leather tanning. Regarding what concerns the silver leaf, where the varnish cracked, silver chlorides, oxides, and sulfides were detected as degradation products of the silver leaf. Proteinaceous compounds were also identified where the silver leaf is unprotected by the varnish. These ion signals reveal a potential use of animal glue on both sides of the silver leaf to promote durable adhesion. In the gold varnish, the surface analysis revealed organic compounds such as resins and oils. In particular, the copresence of linoleic, arachidonic, and lignoceric acid ion signals in the yellow area suggests the use of aloe as a colorant. Lead ions in the same area were detected and attributed to the use of lead as siccative. Blue areas were obtained by using indigo and lead white in addition to an oil binder. This is confirmed by the detection of indigotin, fatty acid, and lead soap ion signals. A copper-based pigment was used to depict the green areas and copper oxalates were identified as its degradation products. Lastly, no significant information about the red colorant was obtained. Colophony is present as a component of the final varnish
Dynamics of black hole-neutron star binaries in young star clusters
Young star clusters are likely the most common birthplace of massive stars across cosmic time and influence the formation of compact binaries in several ways. Here, we simulate the formation of black hole-neutron star binaries (BHNSs) in young star clusters, by means of the binary population synthesis code MOBSE interfaced with the N-body code NBODY6++GPU. BHNSs formed in young star clusters (dynamical BHNSs) are significantly more massive than BHNSs formed from isolated binaries (isolated BHNSs): ~40 per cent of the dynamical BHNS mergers have a total mass of > 15 M0, while only ~0.01 per cent of the isolated BHNS mergers have mass in excess of this value. Hence, our models strongly support a dynamical formation scenario for GW190814, given its total mass of ~26 M0, if this event is a BHNS merger. All our dynamical BHNSs are ejected from their parent star cluster before they reach coalescence. Thus, a significant fraction of BHNS mergers occurring in the field might have originated in a young star cluster. The mass spectrum of BHNS mergers from gravitational-wave detections will provide a clue to differentiate between dynamical and isolated formation of BHNSs
Transannular patching is a valid alternative for tetralogy of Fallot and complete atrioventricular septal defect repair
Objective: We report our experience with repair of tetralogy of Fallot associated with complete atrioventricular
septal defect, addressing in particular the need for a pulmonary valve in the right ventricular outflow tract.
Methods: Between 1992 and 2006, 33 children with tetralogy of Fallot and complete atrioventricular septal defect
were admitted; 26 had Down’s syndrome (79%). Thirty-two children had complete repair (18 primary, 14
staged); of the 15 who received initial palliation, 1 died before complete repair. Right ventricular outflow tract
obstruction was relieved by transannular patch in 14 cases (42%), infundibular patch with preservation of the
pulmonary valve in 7 (21%), and right ventricle–to–pulmonary artery conduit in 11 (33%).
Results: There were no hospital deaths. Actuarial survival was 96% 3.9% at 5 years and 85.9 1.1% at 10
years. Multivariate analysis showed that type of relief of right ventricular outflow tract obstruction did not influence
survival (P ¼ .16), nor did the choice to use a valved conduit (P ¼ .82). Primary correction (P ¼ .05) and
lower weight at repair (P ¼ .05) were associated with higher probability of survival. Mean follow-up was 69.3
5.9 months (range 0.2–282 months). There were 2 late deaths. Overall freedom from reoperation was 69% at 5
years and 38%at 10 years. Right ventricular outflow tract reconstruction without use of a valved conduit allowed
a significantly higher freedom from reinterventions (P<.05).
Conclusions: Tetralogy of Fallot associated with complete atrioventricular septal defect can be corrected at low
risk with favorable intermediate survival. Use of right ventricle–to–pulmonary artery conduit can be avoided in
two thirds of patients with no impact on survival, possibly improving overall freedom from reintervention
Transannular patching is a valid alternative for tetralogy of Fallot and complete atrioventricular septal defect repair
Objective: We report our experience with repair of tetralogy of Fallot associated with complete atrioventricular
septal defect, addressing in particular the need for a pulmonary valve in the right ventricular outflow tract.
Methods: Between 1992 and 2006, 33 children with tetralogy of Fallot and complete atrioventricular septal defect
were admitted; 26 had Down’s syndrome (79%). Thirty-two children had complete repair (18 primary, 14
staged); of the 15 who received initial palliation, 1 died before complete repair. Right ventricular outflow tract
obstruction was relieved by transannular patch in 14 cases (42%), infundibular patch with preservation of the
pulmonary valve in 7 (21%), and right ventricle–to–pulmonary artery conduit in 11 (33%).
Results: There were no hospital deaths. Actuarial survival was 96% 3.9% at 5 years and 85.9 1.1% at 10
years. Multivariate analysis showed that type of relief of right ventricular outflow tract obstruction did not influence
survival (P ¼ .16), nor did the choice to use a valved conduit (P ¼ .82). Primary correction (P ¼ .05) and
lower weight at repair (P ¼ .05) were associated with higher probability of survival. Mean follow-up was 69.3
5.9 months (range 0.2–282 months). There were 2 late deaths. Overall freedom from reoperation was 69% at 5
years and 38%at 10 years. Right ventricular outflow tract reconstruction without use of a valved conduit allowed
a significantly higher freedom from reinterventions (P<.05).
Conclusions: Tetralogy of Fallot associated with complete atrioventricular septal defect can be corrected at low
risk with favorable intermediate survival. Use of right ventricle–to–pulmonary artery conduit can be avoided in
two thirds of patients with no impact on survival, possibly improving overall freedom from reintervention
Estrogen-dependent dynamic profile of eNOS-DNA associations in prostate cancer
In previous work we have documented the nuclear translocation of endothelial NOS (eNOS) and its participation in combinatorial complexes with Estrogen Receptor Beta (ERβ) and Hypoxia Inducible Factors (HIFs) that determine localized chromatin remodeling in response to estrogen (E2) and hypoxia stimuli, resulting in transcriptional regulation of genes associated with adverse prognosis in prostate cancer (PCa). To explore the role of nuclear eNOS in the acquisition of aggressive phenotype in PCa, we performed ChIP-Sequencing on chromatin-associated eNOS from cells from a primary tumor with poor outcome and from metastatic LNCaP cells. We found that: 1. the eNOS-bound regions (peaks) are widely distributed across the genome encompassing multiple transcription factors binding sites, including Estrogen Response Elements. 2. E2 increased the number of peaks, indicating hormone-dependent eNOS re-localization. 3. Peak distribution was similar with/without E2 with ≈ 55% of them in extragenic DNA regions and an intriguing involvement of the 5′ domain of several miRs deregulated in PCa. Numerous potentially novel eNOS-targeted genes have been identified suggesting that eNOS participates in the regulation of large gene sets. The parallel finding of downregulation of a cluster of miRs, including miR-34a, in PCa cells associated with poor outcome led us to unveil a molecular link between eNOS and SIRT1, an epigenetic regulator of aging and tumorigenicity, negatively regulated by miR-34a and in turn activating eNOS. E2 potentiates miR-34a downregulation thus enhancing SIRT1 expression, depicting a novel eNOS/SIRT1 interplay fine-tuned by E2-activated ER signaling, and suggesting that eNOS may play an important role in aggressive PCa
Revision of previous Fontan connections to total extracardiac cavopulmonary anastomosis: A multicenter experience
AbstractBackground: Conversion to total extracardiac cavopulmonary anastomosis is an option for managing patients with dysfunction of a prior Fontan connection. Methods: Thirty-one patients (19.9 ± 8.8 years) underwent revision of a previous Fontan connection to total extracardiac cavopulmonary anastomosis at four institutions. Complications of the previous Fontan connection included atrial tachyarrhythmias (n = 20), progressive heart failure (n = 17), Fontan pathway obstruction (n = 10), effusions (n = 10), pulmonary venous obstruction by an enlarged right atrium (n = 6), protein-losing enteropathy (n = 3), right atrial thrombus (n = 2), subaortic stenosis (n = 1), atrioventricular valve regurgitation (n = 3), and Fontan baffle leak (n = 5). Conversion to an extracardiac cavopulmonary connection was performed with a nonvalved conduit from the inferior vena cava to the right pulmonary artery, with additional procedures as necessary. Results: There have been 3 deaths. Two patients died in the perioperative period of heart failure and massive effusions. The third patient died suddenly 8 months after the operation. All surviving patients were in New York Heart Association class I (n = 20) or II (n = 7), except for 1 patient who underwent heart transplantation. Early postoperative arrhythmias occurred in 10 patients: 4 required pacemakers, and medical therapy was sufficient in 6. In 15 patients, pre-revision arrhythmias were improved. Effusions resolved in all but 1 of the patients in whom they were present before revision. The condition of 2 patients with protein-losing enteropathy improved within 30 days. Conclusions: Conversion of a failing Fontan connection to extracardiac cavopulmonary connection can be achieved with low morbidity and mortality. Optimally, revision should be undertaken early in symptomatic patients before irreversible ventricular failure ensues. (J Thorac Cardiovasc Surg 2000;119:340-6
rs4919510 in hsa-mir-608 Is Associated with Outcome but Not Risk of Colorectal Cancer
Colorectal cancer is the third most incident cancer and cause of cancer-related death in the United States. MicroRNAs, a class of small non-coding RNAs, have been implicated in the pathogenesis and prognosis of colorectal cancer, although few studies have examined the relationship between germline mutation in the microRNAs with risk and prognosis. We therefore investigated the association between a SNP in hsa-mir-608, which lies within the 10q24 locus, and colorectal cancer.A cohort consisting of 245 cases and 446 controls was genotyped for rs4919510. The frequency of the GG genotype was significantly higher in African Americans (15%) compared to Caucasians (3%) controls. There was no significant association between rs4919510 and colorectal cancer risk (African American: OR(GG vs. CC) 0.89 [95% CI, 0.41-1.80]) (Caucasian: OR(GG vs. CC) 1.76, ([95% CI, 0.48-6.39]). However, we did observe an association with survival. The GG genotype was associated with an increased risk of death in Caucasians (HR(GG vs. CC) 3.54 ([95% CI, 1.38-9.12]) and with a reduced risk of death in African Americans (HR(GG vs. CC) 0.36 ([95% CI 0.12-1.07).These results suggest that rs4910510 may be associated with colorectal cancer survival in a manner that is dependent on race
How the First Year of the COVID-19 Pandemic Impacted Patients’ Hospital Admission and Care in the Vascular Surgery Divisions of the Southern Regions of the Italian Peninsula
Background: To investigate the effects of the COVID-19 lockdowns on the vasculopathic population. Methods: The Divisions of Vascular Surgery of the southern Italian peninsula joined this multicenter retrospective study. Each received a 13-point questionnaire investigating the hospitalization rate of vascular patients in the first 11 months of the COVID-19 pandemic and in the preceding 11 months. Results: 27 out of 29 Centers were enrolled. April-December 2020 (7092 patients) vs. 2019 (9161 patients): post-EVAR surveillance, hospitalization for Rutherford category 3 peripheral arterial disease, and asymptomatic carotid stenosis revascularization significantly decreased (1484 (16.2%) vs. 1014 (14.3%), p = 0.0009; 1401 (15.29%) vs. 959 (13.52%), p = 0.0006; and 1558 (17.01%) vs. 934 (13.17%), p < 0.0001, respectively), while admissions for revascularization or major amputations for chronic limb-threatening ischemia and urgent revascularization for symptomatic carotid stenosis significantly increased (1204 (16.98%) vs. 1245 (13.59%), p < 0.0001; 355 (5.01%) vs. 358 (3.91%), p = 0.0007; and 153 (2.16%) vs. 140 (1.53%), p = 0.0009, respectively). Conclusions: The suspension of elective procedures during the COVID-19 pandemic caused a significant reduction in post-EVAR surveillance, and in the hospitalization of asymptomatic carotid stenosis revascularization and Rutherford 3 peripheral arterial disease. Consequentially, we observed a significant increase in admissions for urgent revascularization for symptomatic carotid stenosis, as well as for revascularization or major amputations for chronic limb-threatening ischemia
Shape similarity, better than semantic membership, accounts for the structure of visual object representations in a population of monkey inferotemporal neurons
The anterior inferotemporal cortex (IT) is the highest stage along the hierarchy of visual areas that, in primates, processes visual objects. Although several lines of evidence suggest that IT primarily represents visual shape information, some recent studies have argued that neuronal ensembles in IT code the semantic membership of visual objects (i.e., represent conceptual classes such as animate and inanimate objects). In this study, we investigated to what extent semantic, rather than purely visual information, is represented in IT by performing a multivariate analysis of IT responses to a set of visual objects. By relying on a variety of machine-learning approaches (including a cutting-edge clustering algorithm that has been recently developed in the domain of statistical physics), we found that, in most instances, IT representation of visual objects is accounted for by their similarity at the level of shape or, more surprisingly, low-level visual properties. Only in a few cases we observed IT representations of semantic classes that were not explainable by the visual similarity of their members. Overall, these findings reassert the primary function of IT as a conveyor of explicit visual shape information, and reveal that low-level visual properties are represented in IT to a greater extent than previously appreciated. In addition, our work demonstrates how combining a variety of state-of-the-art multivariate approaches, and carefully estimating the contribution of shape similarity to the representation of object categories, can substantially advance our understanding of neuronal coding of visual objects in cortex
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