908 research outputs found

    Non-diagonal open spin-1/2 XXZ quantum chains by separation of variables: Complete spectrum and matrix elements of some quasi-local operators

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    The integrable quantum models, associated to the transfer matrices of the 6-vertex reflection algebra for spin 1/2 representations, are studied in this paper. In the framework of Sklyanin's quantum separation of variables (SOV), we provide the complete characterization of the eigenvalues and eigenstates of the transfer matrix and the proof of the simplicity of the transfer matrix spectrum. Moreover, we use these integrable quantum models as further key examples for which to develop a method in the SOV framework to compute matrix elements of local operators. This method has been introduced first in [1] and then used also in [2], it is based on the resolution of the quantum inverse problem (i.e. the reconstruction of all local operators in terms of the quantum separate variables) plus the computation of the action of separate covectors on separate vectors. In particular, for these integrable quantum models, which in the homogeneous limit reproduce the open spin-1/2 XXZ quantum chains with non-diagonal boundary conditions, we have obtained the SOV-reconstructions for a class of quasi-local operators and determinant formulae for the covector-vector actions. As consequence of these findings we provide one determinant formulae for the matrix elements of this class of reconstructed quasi-local operators on transfer matrix eigenstates.Comment: 40 pages. Minor modifications in the text and some notations and some more reference adde

    DENS INVAGINATUS (DENS IN DENTE): A MULTIDISCIPLINARY APPROACH. CASE REPORT

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    Aim: The purpose of this report was to demonstrate how a multidisciplinary surgical and endodontic approach in this type of tooth anomaly, may improve the prognosis both functionally and aesthetically. Dens invaginatus is a developmental anomaly resulting from infolding of the surface of the tooth crown before calcification has occurred. Many mechanisms have been proposed as a cause of this phenomenon, including local delay in enamel formation, infolding of the enamel organ within the dental pulp and local external influences on the tooth germ, but the aetiology of dens in dente is still not entirely known. The most common teeth interested by this malformation are maxillary lateral incisors, sometimes it occurs bilaterally. Morphologically the malformation is classified in three types: Type I: An enamel-lined minor invagination occurring within the crown not extending beyond the amelocemental junction. Type II: An enamel-lined form that invades the root but remains confined as a blind sac. It may or not communicate with dental pulp. Type III: a form that penetrates through the root perforating at the apical area showing “a second foramen” in the apical or periodontal area. There is no immediate communication with the pulp. The invagination may be completely lined by enamel, but frequently cementum will be found lining the invagination. The invagination commonly communicates with the oral cavity, allowing the entry of irritants and microorganisms either to the pulpal tissue or to an area that is only separated from pulpal tissue by a thin layer of dentin or enamel. This continual admission of irritants and the consequent inflammation usually leads to necrosis of the adjacent pulpal tissue and induces a periodontal or apical abscess. Other reported sequels of undiagnosed and untreated invaginated teeth include cysts, delay eruption and internal resorption. Sometimes Dens in Dente is associated with dental anomalies like taurodontia, microdontia, supernumerary teeth, gemination, and dentinogenesis imperfecta. Description and procedures: A 24- year old male patient came to the Dental Clinic for aesthetic reasons. Intraoral examination disclosed the presence of a maxillary right lateral incisor with unusual morphological features. The crown of the tooth had a peg-shaped appearance. Radiological evaluation showed that a large periapical lesion existed corresponding to the area of the lateral incisor, and irregular root canal borders and an enamel-lined invagination extended through the root. A Type III Dens Invaginatus was diagnosed. The patient was invited to have a maxillary Dental Scan done that showed exactly the wideness of the bone loss. After several irrigations with 5% NaClO, the endodontic treatment was performed: Ca(OH)2 was left in the root canal for one month and then Thermafil Obturators (Dentsply, Maillefer) were used for endodontic closure. After eight months, although the initial improvement , we decided for the surgical removal of the cysts and apicectomy of the tooth. Conclusion: Dens invaginatus has an unpredictable root canals anatomy. For a good clinical outcome we need to associate the surgical approach with the endodontic treatment

    Duration of remission after halving of the etanercept dose in patients with ankylosing spondylitis: a randomized, prospective, long-term, follow-up study

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    Fabrizio Cantini, Laura Niccoli, Emanuele Cassarà, Olga Kaloudi, Carlotta NanniniDivision of Rheumatology, Misericordia e Dolce Hospital, Prato, ItalyBackground: The aim of this study was to evaluate the proportion of patients with ankylosing spondylitis maintaining clinical remission after reduction of their subcutaneous etanercept dose to 50 mg every other week compared with that in patients receiving etanercept 50 mg weekly.Methods: In the first phase of this randomized, prospective, follow-up study, all biologic-naïve patients identified between January 2005 and December 2009 as satisfying the modified New York clinical criteria for ankylosing spondylitis treated with etanercept 50 mg weekly were evaluated for disease remission in January 2010. In the second phase, patients meeting the criteria for remission were randomized to receive subcutaneous etanercept as either 50 mg weekly or 50 mg every other week. The randomization allocation was 1:1. Remission was defined as Bath Ankylosing Spondylitis Disease Activity Index < 4, no extra-axial manifestations of peripheral arthritis, dactylitis, tenosynovitis, or iridocyclitis, and normal acute-phase reactants. The patients were assessed at baseline, at weeks 4 and 12, and every 12 weeks thereafter. The last visit constituted the end of the follow-up.Results: During the first phase, 78 patients with ankylosing spondylitis (57 males and 21 females, median age 38 years, median disease duration 12 years) were recruited. In January 2010, after a mean follow-up of 25 ± 11 months, 43 (55.1%) patients achieving clinical remission were randomized to one of the two treatment arms. Twenty-two patients received etanercept 50 mg every other week (group 1) and 21 received etanercept 50 mg weekly (group 2). At the end of follow-up, 19 of 22 (86.3%) subjects in group 1 and 19 of 21 (90.4%) in group 2 were still in remission, with no significant difference between the two groups. The mean follow-up duration in group 1 and group 2 was 22 ± 1 months and 21 ± 1.6 months, respectively.Conclusion: Remission of ankylosing spondylitis is possible in at least 50% of patients treated with etanercept 50 mg weekly. After halving of the etanercept dose, remission is maintained in a high percentage of patients during long-term follow-up, with important economic implications.Keywords: ankylosing spondylitis, anti-tumor necrosis factor, etanercept, remission, dose reductio

    Myocardial and microvascular injury due to Coronavirus disease 2019

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    Over the past few months, health systems worldwide have been put to the test with the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Even though the leading clinical manifestations of the SARS-CoV-2 infection involve the respiratory tract, there is a non-negligible risk of systemic involvement leading to the onset of multi-organ failure with fatal consequences. Since the onset of COVID-19, patients with underlying cardiovascular disease have been at increased risk of poor clinical outcomes with higher death rates. Moreover, the occurrence of new-onset cardiac complications is not uncommon among patients hospitalised for COVID-19. Of importance, a significant portion of COVID-19 patients present with myocardial injury. Herein, the authors discuss the mechanisms leading to myocardial and microvascular injury in SARS-CoV-2 infection and their clinical implications

    Potential pesticide transport in Colorado agriculture: a model comparison

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    .30 September 1989.Includes bibliographical references (pages [50]-52)Grant no. 14-08-0001-1551, Project no. 09; financed in part by the U.S. Department of the Interior, Geological Survey, through the Colorado Water Resources Research Institute

    Response to erlotinib in a patient with lung adenocarcinoma harbouring the EML4-ALK translocation: A case report.

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    Lung cancer is the leading cause of cancer-associated mortality worldwide, and the mainstay of treatment remains to be personalised therapy. Tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR-TKIs) have been reported to exert a significant impact in the treatment of non-small cell lung cancer (NSCLC), particularly in patients harbouring mutations in the EGFR gene. The echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) gene translocation has been described in a subset of patients with NSCLC and possesses potent oncogenic activity. This translocation represents one of the most novel molecular targets in the treatment of NSCLC. Patients who harbour the EML4-ALK rearrangement possess lung tumours that lack EGFR or K-ras mutations. The present study reports the case of a patient possessing the EML4-ALK rearrangement that was initially treated with erlotinib and achieved a lasting clinical response. To the best of our knowledge, the current study is the first report of a clinical response to EGFR-TKI in a patient with lung adenocarcinoma harbouring the EML4-ALK fusion gene, but no EGFR mutations. However, as the disease progressed, the ALK gene status of the tumour was investigated, and based upon a positive result, the patient was treated with crizotinib and achieved a complete response. In conclusion, the present study suggests that the EML4-ALK rearrangement is not always associated with resistance to EGFR-TKIs. Further studies are required to clarify the biological features of these tumours and to investigate the mechanisms underlying the primary resistance to EGFR-TKIs when the EML4-ALK rearrangement is present

    The role of 18F-FDG PET/CT in endometrial adenocarcinoma: a review of the literature and recent advances

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    Purpose: To provide a substantial coverage on the role of 18F-FDG PET/CT in endometrial cancer (EC), and identify the key issues which make its use recommended with both low level of evidence and low strength of recommendation in accordance with the last consensus conference. Methods: A comprehensive literature computer search was performed on PubMed/MEDLINE and Cochrane Library databases up to June 2020. Included studies had to focus on 18F-FDG PET/CT in EC, with regard to staging, follow-up and prognostic value. Review guidelines, systematic review, meta-analyses and original papers were included. Results: The 18F-FDG PET/CT is affected by suboptimal soft tissue differentiation, with sensitivity and specificity in tumor staging ranged from 77 to 85% and 79 to 96%. The sensitivity and the specificity of 18F-FDG PET/CT performed at staging for lymph node metastases ranged from 63 to 73% and 96 to 97%. For distant metastases, sensitivity and specificity of 18F-FDG PET/CT performed at staging ranged from 63 to 80% and 93 to 96%. After treatment, better performance emerged for EC recurrent with sensitivity ranged from 92 to 98% and specificity ranged from 89 to 94%. Maximum standardized uptake value (SUVmax) and metabolic volumetric parameters, such as total lesion glycolysis (TLG) and metabolic tumor volume (MTV), resulted to be significantly related to prognosis. Conclusion: Despite evidence-based data about the diagnostic performance are increasing, the low sensitivity represents the main limitation of 18F-FDG PET/CT imaging utilization for the detection of primary tumor and lymph node metastases. Better performances were observed for distant metastasis and EC recurrence. Further randomized prospective studies are needed to increase both the low level of evidence and low strength of recommendation for using 18F-FDG PET/CT in EC. Promising results emerged from PET/MRI

    Procedural Impact of a Kissing-Balloon Predilation (Pre-Kissing) Technique in Patients With Complex Bifurcations Undergoing Drug-Eluting Stenting

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    Aim: To assess the impact of lesion predilation with kissing inflation using under-sized balloons (pre-kissing [PK]) on the procedural outcome of percutaneous intervention (PCI) on coronary bifurcation lesions (CBLs). Methods: Patients who underwent PCI with second-generation drug-eluting stenting on a complex CBL (Medina 1,1,1 or 1,0,1 or 0,1,1) were selected. The study population was divided according to the lesion preparation into the PK group and the control group. To adjust for higher anatomic complexity of PK patients, a 2:1 propensity-matched (PM)-control group was selected. The PCI procedural details were assessed to evaluate occurrence of "side-branch trouble" (primary procedural endpoint) after main-vessel (MV) stenting. Angiographic characteristics, including side-branch TIMI flow during PCI, were also systematically evaluated. Results: A total of 538 patients were identified, with 66 patients in the PK group, 472 patients in the control group, and 126 patients in the PM-control group. Side-branch trouble was less common in side-branch PK patients vs the PM-control patients (7.5% vs 18.0%, respectively; P=.03). In multivariable analysis, the absence of PK independently predicted side-branch trouble. Among selected patients with a long side-branch lesion (122 patients), the PK technique improved post-MV stenting side-branch TIMI flow. Conclusions: Use of PK with under-sized balloons may facilitate side-branch management after MV stenting in patients with complex CBL undergoing provisional stenting

    Human coronary inflammation by computed tomography: Relationship with coronary microvascular dysfunction

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    Background A new imaging metric using coronary computed tomography angiography (CCTA), addressing the peri-coronary adipose tissue (PCAT) computed tomography (CT) attenuation, has been clinically validated. This method provides information regarding coronary inflammation. It is unclear how coronary inflammation affects microvascular function. The non-invasive evaluation of coronary flow velocity reserve is widely used in clinical practice using Doppler measurement on the left anterior descending coronary artery (CFVR-lad) during stress-echocardiography (SE). We hypothesize that coronary inflammation affects CFVR-lad and, in the absence of overt CAD, they are significantly correlated. Methods We evaluated the relationship between coronary inflammation (by PCAT CT attenuation) and coronary microvascular function (by CFVR-lad) in subjects with no or non-obstructive (diameter stenosis <70%) coronary artery disease (CAD). Results Two-hundred and two subjects were enrolled in the study. The relationship between PCAT CT attenuation and CFVR-lad show a significant inverse relationship in the entire group of subjects enrolled in the study (r = −0.32, p < 0.001). Correlation between PCAT CT attenuation and CFVR-lad was significant in subjects with no or mild CAD-lad, while this was not the case in subjects with intermediate CAD-lad. The R and R2 were respectively −0.40, −0.16 in subjects without CAD (p < 0.001) and − 0.35 and − 0.12 in subjects with mild CAD-lad (p = 0.001). Conclusions The main finding of the current study is the independent relationship between coronary microvascular function, by Doppler CFVR-lad during SE, in subjects without severely obstructive CAD in the left anterior descending coronary artery, and the level of local coronary inflammation, by PCAT attenuation measurement on CCTA
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