1,037 research outputs found
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
Correlated electron-hole plasma in organometal perovskites
Organic-inorganic perovskites are a class of solution-processed semiconductors holding promise for the realization of low-cost efficient solar cells and on-chip lasers. Despite the recent attention they have attracted, fundamental aspects of the photophysics underlying device operation still remain elusive. Here we use photoluminescence and transmission spectroscopy to show that photoexcitations give rise to a conducting plasma of unbound but Coulomb-correlated electron-hole pairs at all excitations of interest for light-energy conversion and stimulated optical amplification. The conductive nature of the photoexcited plasma has crucial consequences for perovskite-based devices: in solar cells, it ensures efficient charge separation and ambipolar transport while, concerning lasing, it provides a low threshold for light amplification and justifies a favourable outlook for the demonstration of an electrically driven laser. We find a significant trap density, whose cross-section for carrier capture is however low, yielding a minor impact on device performance
The MEV project: design and testing of a new high-resolution telescope for Muography of Etna Volcano
The MEV project aims at developing a muon telescope expressly designed for
the muography of Etna Volcano. In particular, one of the active craters in the
summit area of the volcano would be a suitable target for this experiment. A
muon tracking telescope with high imaging resolution was built and tested
during 2017. The telescope is a tracker based on extruded scintillating bars
with WLS fibres and featuring an innovative read-out architecture. It is
composed of three XY planes with a sensitive area of \SI{1}{m^2}; the angular
resolution does not exceeds \SI{0.4}{\milli\steradian} and the total angular
aperture is about \SI{45}{\degree}. A special effort concerned the design
of mechanics and electronics in order to meet the requirements of a detector
capable to work in a hostile environment such as the top of a tall volcano, at
a far distance from any facility. The test phase started in January 2017 and
ended successfully at the end of July 2017. An extinct volcanic crater (the
Monti Rossi, in the village of Nicolosi, about 15km from Catania) is the target
of the measurement. The detector acquired data for about 120 days and the
preliminary results are reported in this work
Hand-arm vibration in motocross: measurement and mitigation actions
SUMMARY
Objective. This study focused on the quantification of vibration which reaches the hands of motocross riders and on the reduction of such vibration thanks to the handlebar and handlebar mounts.
Background. Vibration transmitted through the hand and arm can lead to vascular and musculo- skeletal problems that are well documented in the scientific literature. Controlled studies identi- fying plate-handlebar characteristics effects on the vibration attenuation in motocross are lacking. Methods. We measured the vibration exposure of professional and recreational motocross riders on a motocross track and replicated the vibration patterns on a LDS V930 shaker in the laboratory, to analyze the effectiveness of various components in reducing the rider vibration exposure. Labo- ratory tests were performed with ten subjects randomly gripping different combinations of handle- bars and steering plates, and questionnaires were used to evaluate the comfort. Objective measure- ments of vibration reduction were then compared to the subjective values of perceived comfort. Results. According to the current EU legislation, the measured vibration levels reach the expo- sure limit in less than 1h. The mechanical characteristics of the handlebars and steering plates have a limited effect on the vibration transmitted to the rider’s hands. The rubber elements that many manufacturers use to reduce the vibration have limited effects at frequencies that are harmful for the musculoskeletal system. Questionnaires results have no correlation with the measured plate and handlebar performances.
Conclusions. Most of the techniques used to reduce the hand-arm vibration exposure of moto- cross drivers are ineffective
Periodontal and Orthodontic Synergy in the Management of Stage IV Periodontitis: Challenges, Indications and Limits
This retrospective study described the clinical and radiographic long-term outcomes of combined periodontal and orthodontic treatment (OT) with fixed appliances in patients with Stage IV periodontitis and pathologic tooth migration (PTM) in the anterior sextants. OT was performed in either one or both arches, using tooth-supported or skeletal anchorage, following completion of active periodontal treatment and accurate planning of tooth movement biomechanics. Twenty-nine patients were identified and retrospectively examined when presenting for a supportive periodontal care (SPC) appointment. The mean SPC duration was 8.9 years (range 5 to 12 years). All anterior-migrated teeth showed statistically significant periodontal improvement compared to baseline values and stable radiographic bone levels at the final follow-up. Residual probing depths were 2.9 ± 0.5 mm at the end of active periodontal treatment, and they remained stable at the completion of OT (2.9 ± 0.6 mm) and at the last follow-up visit (2.8 ± 0.5 mm). These findings suggest that OT is a safe and effective treatment in improving the long-term prognosis of teeth with PTM in Stage IV periodontitis provided that periodontal health has been re-established and maintained with individualized SPC sessions
Random laser action in self-organized para-sexiphenyl nanofibers grown by hot-wall epitaxy
We report on the observation of amplified spontaneous emission and random lasing in self-organized crystalline para-sexiphenyl nanofibers. Using subpicosecond excitation, a lasing threshold is observed on the 0-1 emission band near 425 nm at excitation fluences as low as 0.5 muJ/cm(2) (6x10(16) cm(-3) equivalent density), near the onset of density-dependent recombination processes. The dependence of the nonlinear emission spectrum on both the pump intensity and position of the excitation area are attributed to the interplay between random lasing and amplified spontaneous emission occurring along the nanofibers
Near infrared light emission quenching in organolanthanide complexes
We investigate the quenching of the near infrared light emission in Er3+ complexes induced by the resonant dipolar interaction between the rare-earth ion and high frequency vibrations of the organic ligand. The nonradiative decay rate of the lanthanide ion is discussed in terms of a continuous medium approximation, which depends only on a few, easily accessible spectroscopic and structural data. The model accounts well for the available experimental results in Er3+ complexes, and predicts an similar to 100% light emission quantum yield in fully halogenated systems
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