3,406 research outputs found
Fast label-free multilayered histology-like imaging of human breast cancer by photoacoustic microscopy
The goal of breast-conserving surgery is to completely remove all of the cancer. Currently, no intraoperative tools can microscopically analyze the entire lumpectomy specimen, which results in 20 to 60% of patients undergoing second surgeries to achieve clear margins. To address this critical need, we have laid the foundation for the development of a device that could allow accurate intraoperative margin assessment. We demonstrate that by taking advantage of the intrinsic optical contrast of breast tissue, photoacoustic microscopy (PAM) can achieve multilayered histology-like imaging of the tissue surface. The high correlation of the PAM images to the conventional histologic images allows rapid computations of diagnostic features such as nuclear size and packing density, potentially identifying small clusters of cancer cells. Because PAM does not require tissue processing or staining, it can be performed promptly and intraoperatively, enabling immediate directed re-excision and reducing the number of second surgeries
Cimentos biocerâmicos na Endodontia
Para obtermos um ambiente livre de bactérias e para a prevenção ou a cura da patologia pulpar e periapical é necessário obtermos uma obturação hermética dos canais radiculares e para isso é imprescindível o uso de um cimento. O objetivo do cimento, quer aplicado por via ortógrada ou retrógrada, é selar a interface entre o material de obturação e as paredes de dentina do canal radicular. Recentemente surgiram os cimentos biocerâmicos baseados em silicato de cálcio que demonstram ter características promissoras.
OBJETIVOS: O objetivo desta revisão bibliográfica sobre cimentos biocerâmicos é analisar a sua eficácia;
as suas propriedades físicas, químicas e biológicas;
os seus usos na endodontia; vantagens e desvantagens e comparar estes materiais com outros mais antigos presentes no mercado.
METODOLOGIA: Para a realização desta revisão bibliográfica foi feita uma pesquisa na base de dados Pubmed e EbscoHost com as seguintes palavras chave: “Bioceramic” e “Endodontics”, “MTA” e “Endodontics” com um limite temporal de 10 anos. Adicionalmente foram utilizados outros artigos citados nos artigos encontrados.
DISCUSSÃO: Os novos cimentos biocerâmicos apresentam boas propriedades de trabalho, tempo de presa mais curto e adequado, pH alcalino, capacidade de libertação de iões de cálcio, biocompatibilidade, grande capacidade de selamento e atividade antibacteriana. Outra vantagem destes cimentos são as novas apresentações clínicas. A sua disponibilização numa seringa já pré-misturada ajuda a reduzir o tempo de trabalho e, ao mesmo tempo, evita problemas associados à mistura do cimento.
CONCLUSÃO: Ainda existem limitações quando comparados com os critérios para um material ideal usado para fins endodônticos, como dificuldade na sua remoção em caso de retratamento e o custo económico. Apesar dos estudos já efetuados sobre os cimentos biocerâmicos, são necessários mais estudos comparativos e estudos a longo prazo para analisar as propriedades químicas e físicas comparativamente com outros materiais e para avaliar a sua eficácia
Preserver Problems on Function Spaces, Operator Algebras, and Related Topics
This special volume of the journal Abstract and Applied Analysis was originally conceived to provide authors and readers a publication to present the most recent advances in the study of those (linear) mappings preserving ranks, spectra, spectral radii, numerical ranges, numerical radii, orthogonality, or disjointness between different, though related, structures studied in Matrix theory, Functional Analysis, and Operator theory, including Function spaces, Operator algebras, and C*-algebras
Performance of Sensing-Based Semi-Persistent Scheduling (SPS) in LTE-V2X Release 14 Distributed Mode
This project will study the different possibilities of access technologies based on LTE in order to provide communications V2V and V2I. This evaluation will be performed by developing a simulator and studying its main communication parameters.The initial standard for cellular-based Vehicle-to-everything (V2X) communications was introduced in 2017 by 3GPP in Long Term Evolution (LTE) Release 14 to serve as a viable alternative to the mature yet dated WLAN-based 802.11p technology. LTE-V2X Release 14 introduced a new arrangement of the resource grid as well as a sensing-based semi-persistent scheduling (SPS) algorithm for the distributed mode in order to reduce latency and increase capacity. A simulator based on open-source software frameworks was developed to evaluate the performance of the Release 14 sensing-based SPS and random allocation in scenarios with varying traffic loads, message sizes, resource keep probabilities P, and collision power thresholds. The performance was then evaluated in terms of Packet Reception Ratio (PRR), occupancy, and goodput, Neighborhood Awareness Ratio (NAR), position error, and latency. Simulation results showed that sensing-based SPS generally performed better than random allocation in terms of PRR in short to medium distances. Sensing-based SPS configured with P=0 performed only slightly better than random allocation in terms of NAR but slightly worse in terms of position error. However, with sufficiently high message traffic, sensing-based SPS performed similar to, or even worse than random allocation
Compromiso organizacional y la satisfacción laboral de los trabajadores de fiscalía provincial Mixta Corporativa del Módulo Básico de Justica de La Esperanza, 2023
El presente estudio tuvo como propósito Identificar la relación entre el compromiso organizacional y la satisfacción laboral de los trabajadores de la fiscalía provincial Mixta Corporativa del Módulo Básico de Justicia de La Esperanza, 2023. La metodología de la investigación fue de tipo aplicada, de enfoque cuantitativo y con diseño no experimental de alcance correlación. La muestra utilizada fueron 19 trabajadores de la Fiscalía Provincial Mixta Corporativa del Módulo Básico de Justicia de La Esperanza. Los resultados demostraron que existe relación significativa p<0.05 positiva de intensidad moderada (,522) entre compromiso organizacional y satisfacción laboral, en cuanto a las dimensiones, existe relación significativa p<0.05 entre la dimensión afectiva (,507) y continuidad (,684) con la variable satisfacción laboral. Se llegó a la conclusión que a mayor compromiso laboral, incentivará a una mayor satisfacción laboral
Characterizing the transition from diffuse atomic to dense molecular clouds in the Magellanic clouds with [CII], [CI], and CO
We present and analyze deep Herschel/HIFI observations of the [CII] 158um,
[CI] 609um, and [CI] 370um lines towards 54 lines-of-sight (LOS) in the Large
and Small Magellanic clouds. These observations are used to determine the
physical conditions of the line--emitting gas, which we use to study the
transition from atomic to molecular gas and from C^+ to C^0 to CO in their low
metallicity environments. We trace gas with molecular fractions in the range
0.1<f(H2)<1, between those in the diffuse H2 gas detected by UV absorption
(f(H2)<0.2) and well shielded regions in which hydrogen is essentially
completely molecular. The C^0 and CO column densities are only measurable in
regions with molecular fractions f(H2)>0.45 in both the LMC and SMC. Ionized
carbon is the dominant gas-phase form of this element that is associated with
molecular gas, with C^0 and CO representing a small fraction, implying that
most (89% in the LMC and 77% in the SMC) of the molecular gas in our sample is
CO-dark H2. The mean X_CO conversion factors in our LMC and SMC sample are
larger than the value typically found in the Milky Way. When applying a
correction based on the filling factor of the CO emission, we find that the
values of X_CO in the LMC and SMC are closer to that in the Milky Way. The
observed [CII] intensity in our sample represents about 1% of the total
far-infrared intensity from the LOSs observed in both Magellanic Clouds.Comment: 32 pages, 21 figures, Accepted to Ap
Producción y precio del petróleo en el mercado internacional 2008 – 2014
El objetivo de la investigación fue determinar la relación que existe entre la
producción y el precio del petróleo en el mercado internacional durante el periodo
2008-2014.
Desde el punto de vista metodológico, la investigación tiene un diseño no
experimental y es de tipo descriptivo correlacional. Para analizar los datos se ha
utilizado el método estadístico que consiste en organizar los datos a través de
cuadros, presentar los datos a través de gráficos de línea y describir los datos a
través de números estadísticos.
La principal conclusión es que la relación que existe una relación negativa entre la
producción y el precio del petróleo en el comercio internacional durante el periodo
2008-2014 es negativa
Changes in allele frequencies when different genomic coancestry matrices are used for maintaining genetic diversity
A main objective in conservation programs is to maintain genetic variability. This can be achieved using the Optimal Contributions (OC) method that optimizes the contributions of candidates to the next generation by minimizing the global coancestry. However, it has been argued that maintaining allele frequencies is also important. Different genomic coancestry matrices can be used on OC and the choice of the matrix will have an impact not only on the genetic variability maintained, but also on the change in allele frequencies. The objective of this study was to evaluate, through stochastic simulations, the genetic variability maintained and the trajectory of allele frequencies when using two different genomic coancestry matrices in OC to minimize the loss of diversity: (i) the matrix based on deviations of the observed number of alleles shared between two individuals from the expected numbers under Hardy-Weinberg equilibrium (θLH); and (ii) the matrix based on VanRaden's genomic relationship matrix (θVR). The results indicate that the use of θLH resulted in a higher genetic variability than the use of θVR. However, the use of θVR maintained allele frequencies closer to those in the base population than the use of θLH.The research leading to these results has received funding from the Ministerio de Ciencia, Innovación y Universidades, Spain (grant CGL2016-75904-C2-2-P). R. Pong-Wong is funded by the European Union’s Horizon 2020 research and innovation programme under the Grant Agreement n◦772787 (SMARTER) and the Biotechnology and Biological Sciences Research Council through Institute Strategic Programme Grant funding (BBS/E/D/30002275).Peer reviewe
WCDMA downlink capacity of cigar-shaped microcells using soft hand-over with SIR-based power control for over-ground train service
In this paper, the downlink sector capacity of a cigar-shaped microcells using wideband code-division multiple-access (WCDMA) with soft hand-over (SHO) mode is analyzed. The two-slope propagation loss with log-normal shadowing is used in the analysis where a model of eight cigar-shaped microcells is utilized to calculate the downlink sector capacity. The performance of the downlink is studied for different sector radii, standard deviations of the shadowing and propagation exponents. It is found that, for a sector range higher than 940 m, increasing the sector range will reduce the downlink sector capacity. Also it is found that increasing the value of the propagation parameters will reduce the downlink sector capacity. In many cases, the downlink sector capacity will be code limited since the theoretical downlink sector capacity is higher than the number of codes assigned to each sector. The high theoretical downlink sector capacity is due to the low value (0.06–0.1) of the WCDMA orthogonality factor of rural zone microcells
Benchmarking the cooperative awareness service at application layer with IEEE 802.11p and LTE-PC5 Mode-4
© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Al document ha d’aparèixer l’enllaç a la publicació original a IEEE, o bé al Digital Object Identifier (DOI).Vehicular communications hold the promise of disrupting mobility services and supporting the mass adoption of future autonomous vehicles. Regulators have set aside specific spectrum at the 5.9 GHz band to support Intelligent Transport Systems (ITS) safety applications, for which a world-wide adoption of a standardized radio technology is a key factor to deliver on this promise. Two technologies are currently positioned to begin its commercial path, IEEE 802.11p and LTE-PC5 Mode-4. The main differences between these technologies lie on the design of their channel access mechanisms. This paper provides an analysis of the impact that the Medium Access Control (MAC) mechanisms included in 802.11p and LTE-PC5 Mode-4 will have on the performance of the applications using the Cooperative Awareness Service, applying two new application-level metrics used by safety applications: Neighborhood Awareness Ratio and Position Error. We have found that, even with an equivalent physical layer performance, the MAC layer of LTE-PC5 Mode-4 will mostly outperform the MAC layer of IEEE 802.11p (or its not yet ready enhanced version 802.11bd). However, IEEE 802.11p/bd results in slightly better vehicle positioning accuracy at lower distances.Peer ReviewedPostprint (author's final draft
- …