Carcinoma da próstata: diagnóstico e seguimento

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Analysis of the resolution of split-ring metamaterial lenses with application in parallel magnetic resonance imaging

In this work, we experimentally determine the resolution of split-ring metamaterials lenses with emphasis in magnetic resonance imaging applications. Two small sources are used to determine the minimal resolution of the lens, which is compared with previous theoretical predictions. Taking into account this minimal resolution, a second experiment is designed in order to study the ability of a split-ring lens to improve the localization of the field produced by two closely spaced coils. This ability could find application in parallel magnetic resonance imaging, which take advantage of the distinct coil sensitivities in order to reduce the image acquisition time. © 2011 American Institute of Physics

Pengembangan Lembar Kegiatan Siswa (Lks) Kimia Sma/ma Berbasis Learning Cycle 5e Pada Materi Laju Reaksi

Penelitian ini bertujuan untuk: (1) mengembangkan Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E, (2) mengetahui kualitas Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E, (3) mengetahui efektivitas Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E untuk meningkatkan prestasi belajar siswa. Penelitian dan pengembangan Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E menggunakan prosedur penelitian dan pengembangan dari Borg and Gall yang disederhanakan menjadi 9 tahapan yaitu: (1) penelitian pendahuluan dan pengumpulan data, (2) perencanaan, (3) pengembangan produk, (4) uji coba lapangan awal, (5) revisi produk awal, (6) uji coba pelaksanaan lapangan, (7) penyempurnaan produk hasil uji coba lapangan, (8) uji coba pelaksanaan lapangan, (9) penyempurnaan produk akhir. Analisis Data yang digunakan adalah analisis deskriptif kualitatif. Hasil Penelitian menunjukkan: (1) telah berhasil dikembangkan Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E pada materi Laju Reaksi yang dilakukan berdasarkan tahapan penelitian dan pengembangan R&D yang terdiri dari 9 tahapan, (2) kualitas Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E pada materi Laju Reaksi memiliki kualitas sangat baik pada aspek komponen kelayakan isi, bahasa, penyajian dan kegrafisan dengan persentase sebesar 84,06% berdasarkan penilaian siswa dan 90,88% berdasarkan penilaian guru, (hasil uji efektivitas pada aspek pengetahuan terdapat perbedaan antara kelas eksperimen (pembelajaran dengan menggunakan model Learning Cycle 5E disertai Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E ) dan kelas baseline (pembelajaran dengan menggunakan model pembelajaran Learning Cycle 5E tanpa disertai Lembar Kegiatan Siswa (LKS) berbasis Learning Cycle 5E ),, sedangkan pada aspek sikap dan keterampilan tidak terdapat perbedaan

Cryptographic enforcement of information flow policies without public information via tree partitions

We may enforce an information flow policy by encrypting a protected resource and ensuring that only users authorized by the policy are able to decrypt the resource. In most schemes in the literature that use symmetric cryptographic primitives, each user is assigned a single secret and derives decryption keys using this secret and publicly available information. Recent work has challenged this approach by developing schemes, based on a chain partition of the information flow policy, that do not require public information for key derivation, the trade-off being that a user may need to be assigned more than one secret. In general, many different chain partitions exist for the same policy and, until now, it was not known how to compute an appropriate one. In this paper, we introduce the notion of a tree partition, of which chain partitions are a special case. We show how a tree partition may be used to define a cryptographic enforcement scheme and prove that such schemes can be instantiated in such a way as to preserve the strongest security properties known for cryptographic enforcement schemes. We establish a number of results linking the amount of secret material that needs to be distributed to users with a weighted acyclic graph derived from the tree partition. These results enable us to develop efficient algorithms for deriving tree and chain partitions that minimize the amount of secret material that needs to be distributed.Comment: Extended version of conference papers from ACNS 2015 and DBSec 201

Recognition of Face Identity and Emotion in Expressive Specific Language Impairment

Objective: To study face and emotion recognition in children with mostly expressive specific language impairment (SLI-E). Subjects and Methods: A test movie to study perception and recognition of faces and mimic-gestural expression was applied to 24 children diagnosed as suffering from SLI-E and an age-matched control group of normally developing children. Results: Compared to a normal control group, the SLI-E children scored significantly worse in both the face and expression recognition tasks with a preponderant effect on emotion recognition. The performance of the SLI-E group could not be explained by reduced attention during the test session. Conclusion: We conclude that SLI-E is associated with a deficiency in decoding non-verbal emotional facial and gestural information, which might lead to profound and persistent problems in social interaction and development. Copyright (C) 2012 S. Karger AG, Base

Prostate Indeterminate Lesions on Magnetic Resonance Imaging-Biopsy Versus Surveillance: A Literature Review

CONTEXT: The indeterminate multiparametric prostate magnetic resonance image (mpMRI) lesion is one which cannot be classified as "positive" or "negative" for suspected cancer. Currently, there is no consensus on how to manage patients with indeterminate mpMRIs where areas cannot be classified as positives or negatives (Prostate Imaging Reporting and Data System [PI-RADS] 3 or Likert 3). OBJECTIVE: To define the concept of indeterminate lesion and describe the management strategies that may be adopted for these patients. EVIDENCE ACQUISITION: A literature search of the PubMed database was performed including the search terms "prostate indeterminate lesions", "PI-RADS 3", "Likert 3", "magnetic resonance imaging", and "prostate cancer". EVIDENCE SYNTHESIS: There is no universally accepted definition of what constitutes an indeterminate lesion on mpMRI. This is partly due to the experience of the reporting radiologist and their willingness to call a lesion indeterminate, knowing that this may have consequences for biopsy decisions. This is also partly due to the significant variation in mpMRI acquisition parameters used between different sites. Strategies for managing the indeterminate lesion include: (1) biopsy, where there is a highly variable prevalence of prostate cancer (PCa), reflecting the differences in clinically significant PCa definitions, mpMRI protocols and interobserver variability in characterization of indeterminate lesions and (2) surveillance, where early results suggest that this strategy may be of value for some selected patients with prostate-specific antigen (PSA) monitoring and/or interval mpMRI. The use of prebiopsy MRI, in conjunction with traditional clinical parameters and secondary biomarkers-nomograms, may allow a more accurate selection of patients who can avoid biopsy. CONCLUSIONS: A strategy of close surveillance based on PSA monitoring and interval mpMRI is a feasible management option for motivated patients with indeterminate mpMRI. This surveillance strategy could result in fewer men needing to undergo biopsy, and although early results are promising, long-term results for such a strategy are awaited. PATIENT SUMMARY: In some patients who have an MRI scan of their prostate, the scan may identify an area which may or may not contain cancer. This area is typically called the "indeterminate" lesion. In this report, we attempted to define the concept of indeterminate lesion on multiparametric magnetic resonance (mpMRI) and described the strategies that may be performed for these patients. The use of mpMRI in conjunction with traditional clinical parameters may allow more accurate risk stratification and assessment of the need for prostate biopsy

Near-field examination of perovskite-based superlenses and superlens-enhanced probe-object coupling

A planar slab of negative index material works as a superlens with sub-diffraction-limited imaging resolution, since propagating waves are focused and, moreover, evanescent waves are reconstructed in the image plane. Here, we demonstrate a superlens for electric evanescent fields with low losses using perovskites in the mid-infrared regime. The combination of near-field microscopy with a tunable free-electron laser allows us to address precisely the polariton modes, which are critical for super-resolution imaging. We spectrally study the lateral and vertical distributions of evanescent waves around the image plane of such a lens, and achieve imaging resolution of wavelength/14 at the superlensing wavelength. Interestingly, at certain distances between the probe and sample surface, we observe a maximum of these evanescent fields. Comparisons with numerical simulations indicate that this maximum originates from an enhanced coupling between probe and object, which might be applicable for multifunctional circuits, infrared spectroscopy, and thermal sensors.Comment: 20 pages, 6 figures, published as open access article in Nature Communications (see http://www.nature.com/ncomms/