449 research outputs found
An Altered Derivatives Marketplace: Clearing Swaps Under Dodd-Frank
Though over a year has passed, the impact of the Dodd Frank Act remains unclear. This Note examines the provisions of the Act that relate to swap transactions within the context of pre-reform and postreform markets. In order to reduce the uncertainties inherent in unregulated swap transactions, the Act employs a comprehensive framework, which includes mandatory clearing through derivative clearing organizations, extensive reporting requirements, margin requirements, and position limits. This Note argues that, in doing so, the Dodd Frank Act addresses the fundamental failures of pre-reform derivative markets. However, the importance of the role for derivative clearing organizations under this framework creates a risk that these organizations will become systemically significant, mirroring problems with under-capitalized and over-exposed financial institutions in the downturn
Cytological Diagnoses Associated with Noninvasive Follicular Thyroid Neoplasms with Papillary-Like Nuclear Features According to the Bethesda System for Reporting Thyroid Cytopathology: A Systematic Review and Meta-Analysis.
The recent introduction of noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP) in the World Health Organization classification of thyroid tumors has significantly modified the risk of malignancy of cytological diagnoses. In fact, while this tumor was previously classified as a carcinoma (the encapsulated, noninvasive form follicular variant of papillary thyroid carcinoma), it is now considered a neoplasm with low malignant potential. Given that the cytological features of NIFTP are not specific and overlap with other pathologic entities, there is no specific cytological diagnostic category for NIFTP. To obtain more robust information about the cytological findings associated with NIFTP, published articles were systematically reviewed, and a meta-analysis of the data was conducted.
The review was conducted according to PRISMA guidelines. A comprehensive literature search of the PubMed/MEDLINE and Scopus databases was conducted using a combination of terms "noninvasive," "encapsulated," "follicular variant," "NIFTP," and "thyroid cancer." The search was updated to June 2018, and references of the retrieved articles were also screened. Only original articles reporting the classification of histologically proven NIFTPs with cytological findings according to The Bethesda System for Reporting Thyroid Cytopathology were eligible for inclusion.
The literature search revealed 117 articles, of which 15 were included in the study. All studies were retrospective. A total of 915 NIFTP cases were retrieved. The incidence of cases cytologically classified according to the Bethesda system was as follows: non-diagnostic 3%, benign 10%, atypia of undetermined significance or follicular lesion of undetermined significance 30%, follicular neoplasm or suspicious for a follicular neoplasm 21%, suspicious for malignancy 24%, and malignant 8%. Mild heterogeneity between the studies was found. Publication bias was absent.
This meta-analysis shows that the cytological diagnoses associated with NIFTP by fine-needle aspiration cytology includes a wide spectrum of findings. The majority of cases are cytologically indeterminate, and the remainder may be read as non-diagnostic, benign, or malignant. In order to develop an accurate presurgical diagnosis of these cases, further cytological and/or molecular characteristics need to be identified
Impact of non-invasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP) on risk of malignancy in patients undergoing lobectomy/thyroidectomy for suspected malignancy or malignant fine-needle aspiration cytology findings: a systematic review and meta-analysis.
The second version of The Bethesda System for Reporting Thyroid Cytopathology endorsed the introduction of non-invasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP) as a distinct entity with low malignant potential into clinical practice. Consequently, the risk of malignancy (ROM) of cytological diagnoses has changed, but the magnitude of the change remains uncertain. The present systematic review was undertaken to obtain more robust information about the true impact of NIFTP on the ROM among patients undergoing surgery following a fine-needle aspiration cytology (FNAC) diagnosis of suspicious for malignancy (Bethesda V) or malignant (Bethesda VI). As they are managed surgically, these two diagnostic categories are the primary entities that are clinically impacted by the advent of NIFTP.
Systematic review and meta-analysis.
A comprehensive literature search of online databases was performed in November 2018. The search was conducted looking for data of histologically proven NIFTP with preoperative FNAC.
One-hundred fifty-seven articles were identified and nine were included in the study. Overall, there were 13,752 thyroidectomies with a cancer prevalence of 45.7%. When NIFTP was considered non-malignant, the pooled risk difference for ROM was 5.5%. Applying meta-analysis, the pooled prevalence of NIFTP among nodules with FNAC of Bethesda V or Bethesda VI was 14 and 3%, respectively.
This meta-analysis shows that the inclusion of NIFTP leads to a reduction in the ROM for the Bethesda V and Bethesda VI FNAC diagnostic categories by 14 and 3%, respectively. Clinicians should be aware of these data to avoid overtreatment
Analysis of tissue surrounding thyroid nodules by ultrasound digital images
Since US is not easily reproducible, the digital image analysis (IA) has been proposed so that the image evaluation is not subjective. In fact, IA meets the criteria of objectivity, accurateness, and reproducibility by a matrix of pixels whose value is displayed in a gray level. This study aims at evaluating via IA the tissue surrounding a thyroid nodule (backyard tissue, BT) from goitres with benign (b-BT) and malignant (m-BT) lesions. Sixty-nine US images of thyroid nodules surrounded by adequate thyroid tissue was classified as normoechoic and homogeneous were enrolled as study group. Forty-three US images from normal thyroid (NT) glands were included as controls. Digital images of 800 × 652 pixels were acquired at a resolution of eight bits with a 256 gray levels depth. By one-way ANOVA, the 43 NT glands were not statistically different (P = 0.91). Mean gray level of normal glands was significantly higher than b-BT (P = 0.026), and m-BT (P = 0.0001), while no difference was found between b-BT and m-BT (P = 0.321). NT tissue boundary external to the nodule was found at 6.0 ± 0.5 mm in cancers and 4.0 ± 0.5 mm in benignancies (P = 0.001). These data should indicate that the tissue surrounding a thyroid nodule may be damaged even when assessed as normal by US. This is of interest to investigate the extranodular effects of thyroid tumors
Free thyroxine measurement in clinical practice: how to optimize indications, analytical procedures, and interpretation criteria while waiting for global standardization
Thyroid dysfunctions are among the most common endocrine disorders and accurate biochemical testing is needed to confirm or rule out a diagnosis. Notably, true hyperthyroidism and hypothyroidism in the setting of a normal thyroid-stimulating hormone level are highly unlikely, making the assessment of free thyroxine (FT4) inappropriate in most new cases. However, FT4 measurement is integral in both the diagnosis and management of relevant central dysfunctions (central hypothyroidism and central hyperthyroidism) as well as for monitoring therapy in hyperthyroid patients treated with anti-thyroid drugs or radioiodine. In such settings, accurate FT4 quantification is required. Global standardization will improve the comparability of the results across laboratories and allow the development of common clinical decision limits in evidence-based guidelines. The International Federation of Clinical Chemistry and Laboratory Medicine Committee for Standardization of Thyroid Function Tests has undertaken FT4 immunoassay method comparison and recalibration studies and developed a reference measurement procedure that is currently being validated. However, technical and implementation challenges, including the establishment of different clinical decision limits for distinct patient groups, still remain. Accordingly, different assays and reference values cannot be interchanged. Two-way communication between the laboratory and clinical specialists is pivotal to properly select a reliable FT4 assay, establish reference intervals, investigate discordant results, and monitor the analytical and clinical performance of the method over time
The ultrasound risk stratification systems for thyroid nodule have been evaluated against papillary carcinoma. A meta-analysis
Thyroid imaging reporting and data systems (TIRADS) are used to stratify the malignancy risk of thyroid nodule by ultrasound (US) examination. We conducted a meta-analysis to evaluate the pooled cancer prevalence and the relative prevalence of papillary, medullary, follicular thyroid cancer (PTC, MTC, and FTC) and other malignancies among nodules included in studies evaluating their performance. Four databases were searched until February 2020. Original articles with at least 1000 nodules, evaluating the performance of at least one TIRADS among AACE/ACE/AME, ACR-TIRADS, ATA, EU-TIRADS, or K-TIRADS, and reporting data on the histological diagnosis of malignant lesions were included. The number of malignant nodules, PTC, FTC, MTC and other malignancies in each study was extracted. For statistical pooling of data, a random-effects model was used. Nine studies were included, evaluating 19,494 thyroid nodules. The overall prevalence of malignancy was 34% (95%CI 21 to 49). Among 6162 histologically proven malignancies, the prevalence of PTC, FTC, MTC and other malignancies was 95%, 2%, 1%, and 1%, respectively. A high heterogeneity was found for all the outcomes. A limited number of studies generally conducted using a retrospective design was found, with possible selection bias. Acknowledging this limitation, TIRADSs should be regarded as accurate tools to diagnose PTC only. Proposed patterns and/or cut-offs should be revised and other strategies considered to improve their performance in the assessment of FTC, MTC and other malignancies
DETECTION AND EVALUATION OF TOPOLOGICAL CONSISTENCY IN CITYGML DATASETS
The topological consistency of Boundary-Representation models, meaning here that the incidence graph is homeomorphic with the underlying topology of geographical data, is checked for several CityGML datasets, and a first classification of topological inconsistencies is performed. The analysis is carried out on a spatial database system into which the datasets have been imported. It is found that real-world datasets contain many topologically inconsistent pairs of intersecting polygons. Also data satisfying the ISO/OGC standards can still be topologically inconsistent. In the case when the intersection is a point, topological inconsistency occurs because a vertex lies on a line segment. However, the most frequent topological inconsistencies seem to arise when the intersection of two polygons is a line segment. Consequently, topological queries in present CityGML data cannot rely on the incidence graph only, but must always make costly geometric computations if correct results are to be expected
Unravelling the intricated photophysical behavior of 3-(pyridin-2-yl)triimidazotriazine AIE and RTP polymorphs
The development of purely organic materials showing multicolor fluorescent and phosphorescent behaviour represents a
formidable challenge in view of practical applications. Herein the rich photophyisical behaviour of 3-(pyridin-2-
yl)triimidazotriazine (TT-Py) organic molecule, comprising excitation-dependent fluorescence and phosphorescence under ambient conditions in both blended film and crystalline phase, is investigated by means of steady state, time resolved and ultrafast spectroscopies and interpreted on the basis of X-ray diffraction studies and DFT/TDDFT calculations. In particular, by proper excitation wavelength, dual fluorescence and dual phosphorescence of molecular origin can be observed together with low energy phosphorescences resulting from aggregate species. It is demonstrated that the multiple emission property is originated by the copresence, in the investigated system, of an extended polycyclic nitrogen-rich moiety (TT), strongly rigidified by p-p stacking interactions and short C\u2013H...N hydrogen bonds, and a fragment (Py) featuring partial conformational freedom
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