51 research outputs found
Comparison of reflectance confocal microscopy and line-field optical coherence tomography for the identification of keratinocyte skin tumours
Background: Reflectance confocal microscopy (RCM) and line-field confocal optical coherence tomography (LC-OCT) are non-invasive imaging devices that can help in the clinical diagnosis of actinic keratosis (AK) and cutaneous squamous cell carcinoma (SCC). No studies are available on the comparison between these two technologies for the identification of the different features of keratinocyte skin tumours. Objectives: To compare RCM and LC-OCT findings in AK and SCC. Methods: A retrospective multicenter study was conducted. Tumours were imaged with RCM and LC-OCT devices before surgery, and the diagnosis was confirmed by histological examinations. LC-OCT and RCM criteria for AK/SCC were identified, and their presence/absence was evaluated in all study lesions. Gwet AC1 concordance index was calculated to compare RCM and LC-OCT. Results: We included 52 patients with 33 AKs and 19 SCCs. Irregular epidermis was visible in most tumours and with a good degree of agreement between RCM and LC-OCT (Gwet's AC1 0.74). Parakeratosis, dyskeratotic keratinocytes and both linear dilated and glomerular vessels were better visible at LC-OCT than RCM (p < 0.001). Erosion/ulceration was identified with both methods in more than half of the cases with a good degree of agreement (Gwet AC1 0.62). Conclusions: Our results suggest that both LC-OCT and hand-held RCM can help clinicians in the identification of AK and SCC, providing an in vivo and non-invasive identification of an irregular epidermis. LC-OCT proved to be more effective in identifying parakeratosis, dyskeratotic keratinocytes and vessels in this series
The quest for the solar g modes
Solar gravity modes (or g modes) -- oscillations of the solar interior for
which buoyancy acts as the restoring force -- have the potential to provide
unprecedented inference on the structure and dynamics of the solar core,
inference that is not possible with the well observed acoustic modes (or p
modes). The high amplitude of the g-mode eigenfunctions in the core and the
evanesence of the modes in the convection zone make the modes particularly
sensitive to the physical and dynamical conditions in the core. Owing to the
existence of the convection zone, the g modes have very low amplitudes at
photospheric levels, which makes the modes extremely hard to detect. In this
paper, we review the current state of play regarding attempts to detect g
modes. We review the theory of g modes, including theoretical estimation of the
g-mode frequencies, amplitudes and damping rates. Then we go on to discuss the
techniques that have been used to try to detect g modes. We review results in
the literature, and finish by looking to the future, and the potential advances
that can be made -- from both data and data-analysis perspectives -- to give
unambiguous detections of individual g modes. The review ends by concluding
that, at the time of writing, there is indeed a consensus amongst the authors
that there is currently no undisputed detection of solar g modes.Comment: 71 pages, 18 figures, accepted by Astronomy and Astrophysics Revie
Surprising Sun
Important revisions of the solar model ingredients appear after 35 years of
intense work which have led to an excellent agreement between solar models and
solar neutrino detections. We first show that the updated CNO composition
suppresses the anomalous position of the Sun in the known galactic enrichment.
The following law: He/H= 0.075 + 44.6 O/H in fraction number is now compatible
with all the indicators. We then examine the existing discrepancies between the
standard model and solar - seismic and neutrino - observations and suggest some
directions of investigation to solve them. We update our predicted neutrino
fluxes using the recent composition, new nuclear reaction rates and seismic
models as the most representative of the central plasma properties.
We get 5.31 +- 0.6 10^6/cm^{2}/s for the total ^8B neutrinos, 66.5 SNU and
2.76 SNU for the gallium and chlorine detectors, all in remarquable agreement
with the detected values including neutrino oscillations for the last two. We
conclude that the acoustic modes and detected neutrinos see the same Sun, but
that clear discrepancies in solar modelling encourage further observational and
theoretical efforts.Comment: 4 pages 3 figures Submitted to Phys. Rev. let
Modeling Total Solar Irradiance Variations Using Automated Classification Software on Mount Wilson Data
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Assessing the quality of models of the ambient solar wind
In this paper we present an assessment of the status of models of the global Solar Wind in the inner heliosphere. We limit our discussion to the class of models designed to provide solar wind forecasts, excluding those designed for the purpose of testing physical processes in idealized configurations. In addition, we limit our discussion to modeling of the ‘ambient’ wind in the absence of coronal mass ejections. In this assessment we cover use of the models both in forecast mode and as tools for scientific research. We present a brief history of the development of these models, discussing the range of physical approximations in use. We discuss the limitations of the data inputs available to these models and its impact on their quality. We also discuss current model development trends
The CAESAR project for the ASI space weather infrastructure
This paper presents the project Comprehensive spAce wEather Studies for the ASPIS prototype Realization (CAESAR), which aims to tackle the relevant aspects of Space Weather (SWE) science and develop a prototype of the scientific data centre for Space Weather of the Italian Space Agency (ASI) called ASPIS (ASI SPace Weather InfraStructure). To this end, CAESAR involves the majority of the SWE Italian community, bringing together 10 Italian institutions as partners, and a total of 92 researchers. The CAESAR approach encompasses the whole chain of phenomena from the Sun to Earth up to planetary environments in a multidisciplinary, comprehensive, and unprecedented way. Detailed and integrated studies are being performed on a number of well-observed “target SWE events”, which exhibit noticeable SWE characteristics from several SWE perspectives. CAESAR investigations synergistically exploit a great variety of different products (datasets, codes, models), both long-standing and novel, that will be made available in the ASPIS prototype: this will consist of a relational database (DB), an interface, and a wiki-like documentation structure. The DB will be accessed through both a Web graphical interface and the ASPIS.py module, i.e., a library of functions in Python, which will be available for download and installation. The ASPIS prototype will unify multiple SWE resources through a flexible and adaptable architecture, and will integrate currently available international SWE assets to foster scientific studies and advance forecasting capabilities
Innovation and entrepreneurial ecosystems: Structure, boundaries, and dynamics
Recognizing the broader dimensions of entrepreneurial and innovation activities, holistic and inclusive networked approaches pave the way to co-creation activities that are essential for achieving sustainability in food systems. Recent studies have started to deepen what are the critical enablers for creating thriving entrepreneurial and innovation ecosystems. Networks that include firms, institutions, and several other relevant stakeholders in knowledge spillovers enable to produce more social and economic value through co-creation processes. However, due to the unique complexity within ecosystems, there is no standardized framework or strategy to develop entrepreneurial or innovation ecosystems effectively. In this chapter, a synthesis of the structure, dynamics, and boundaries of innovation and entrepreneurial ecosystems is presented. In particular, the main differences between these two concepts and the traditional ecosystem concept are provided and an overview of the more well-established definitions and frameworks present in the business and management literature offered. So, the following questions and many others will be addressed: what are the critical factors that lead some ecosystems to success? What the key actors? What dynamics characterize them? Answering these questions may represent an effective solution to address sustainability in the multi-functionality of food systems collectively. Therefore, how the heterogeneous elements and complexity of entrepreneurial and innovation ecosystems can be applied in food system sustainability initiatives will be finally discussed and critical action points for policy and practice recommended
Captopril test can give misleading results in patients with suspect primary aldosteronism.
We recently performed a study comparing the SLT with the FST in 100 patients with a positive screening test.4 We report here the results of the captopril test as a confirmatory test in 11 patients in whom SLT and FST displayed concordant results. The captopril test was performed 653 weeks after the previous tests, between 8 am and 10 am, with the subject in the sitting position in a quiet room. Plasma aldosterone concentration and plasma renin activity were measured before and 2 hours after administration of captopril (50 mg). Selection of the patients, diet, therapy, and hormone measurements is described in detail elsewhere.4 Patients were advised to maintain a diet with normal and constant sodium intake (120 mmol of sodium and 60 mmol of potassium per day). All antihypertensive drugs were stopped 653 weeks before the screening test ( 656 weeks for diuretics and 658 weeks for spironolactone). In patients for whom treatment could not be withdrawn for ethical reasons, an \u3b1-blocker (doxazosin) and/or a calcium channel blocker (verapamil) were used for blood pressure control, and the same therapy was maintained throughout the tests.
Six patients who had confirmed PA with both FST and SLT underwent a computed tomography scan and adrenal venous sampling. Three patients had bilateral adrenal hyperplasia, and another 3 patients had an aldosterone-producing adenoma. Five patients with both a negative SLT and FST were considered to be essential hypertensive subjects. Five of 6 patients with PA displayed an plasma aldosterone/plasma renin activity ratio postcaptopril >30 ng dL 121/ng mL 121 h 121, but 1 patient with aldosterone-producing adenoma displayed an plasma aldosterone/plasma renin activity ratio postcaptopril 50% of the basal level during the posture test, indicating an angiotensin II\u2013responsive adenoma. By contrast, 3 of 5 patients who displayed a normal suppression of aldosterone after SLT and FST and, therefore, were classified as being affected by essential hypertensives, displayed a plasma aldosterone/plasma renin activity ratio postcaptopril of >30. These patients would have unnecessarily undergone computed tomography scan and adrenal venous sampling relying only on the captopril test, thereby resulting in increased costs and discomfort for the patients.
The captopril test has been compared previously with the oral saline load in a group of hypertensive patients with spontaneous hypokalemia and, therefore, at very high risk of PA.5 In fact, 44 of 49 were found to be affected by PA, and for this reason, the authors only discussed the sensitivity and not the specificity of the captopril test. Two aspects should be considered to explain the different findings between our study and the study of Agharazii et al5: first, in our study, only 2 patients (1 aldosterone-producing adenoma and 1 bilateral adrenal hyperplasia) were hypokalemic, whereas Agharazii et al studied only hypokalemic patients and, therefore, could have underestimated the possibility of false-negative results in patients with a mild form of PA; second, a proportion of false-positive patients could have been found by Agharazii et al5 if they had studied a larger population of essential hypertensive subjects.
The present data need to be confirmed prospectively in a larger population. However, our findings indicate that, at least in some cases (4 of 11 [36%] in our study), the captopril test was misleading if used as a confirmatory test for the diagnosis of PA. Therefore, in the absence of contraindications such as reduced cardiac or renal function, saline load or FST should be preferred to the captopril test for the confirmatory diagnosis of PA
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