Publications by authors named "Chaplain G"

Frieze patterns follow a set of tiling instructions including reflection, rotation, and translation, and tile the infinite strip. Many metamaterials function due to the underlying symmetry, and its strategic breaking, of their constituent sub-structures that allow tailoring of the dispersion of modes supported by the structure. We design, simulate, and experimentally characterize seven one-dimensional acoustic metasurfaces whose unit cells each belong to one of the distinct Frieze groups.

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The rainbow trapping phenomenon of graded metamaterials can be combined with the fractal spectra of quasiperiodic waveguides to give a metamaterial that performs fractal rainbow trapping. This is achieved through a graded cut-and-project algorithm that yields a geometry for which the effective projection angle is graded along its length. As a result, the fractal structure of local band gaps varies with position, leading to broadband "fractal" rainbow trapping.

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Multi-scale bullseye antennas.

Philos Trans A Math Phys Eng Sci

September 2022

We design, simulate and experimentally characterize a multi-scale bullseye antenna for the broadband manipulation of microwaves. The device achieves far-field beam-forming via tailored diffraction at the interface between two concentric bullseye geometries, with near-field energy concentration resulting from the overlap of the diffracted beams. This article is part of the theme issue 'Wave generation and transmission in multi-scale complex media and structured metamaterials (part 1)'.

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We identify that flexural guided elastic waves in elastic pipes carry a well-defined orbital angular momentum associated with the compressional dilatational potential. This enables the transfer of elastic orbital angular momentum, that we numerically demonstrate, through the coupling of the compressional potential in a pipe to the acoustic pressure field in a surrounding fluid in contact with the pipe.

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Elastic waves guided along surfaces dominate applications in geophysics, ultrasonic inspection, mechanical vibration, and surface acoustic wave devices; precise manipulation of surface Rayleigh waves and their coupling with polarised body waves presents a challenge that offers to unlock the flexibility in wave transport required for efficient energy harvesting and vibration mitigation devices. We design elastic metasurfaces, consisting of a graded array of rod resonators attached to an elastic substrate that, together with critical insight from Umklapp scattering in phonon-electron systems, allow us to leverage the transfer of crystal momentum; we mode-convert Rayleigh surface waves into bulk waves that form tunable beams. Experiments, theory and simulation verify that these tailored Umklapp mechanisms play a key role in coupling surface Rayleigh waves to reversed bulk shear and compressional waves independently, thereby creating passive self-phased arrays allowing for tunable redirection and wave focusing within the bulk medium.

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Strategically combining four structured domains creates the first ever three-way topological energy-splitter; remarkably, this is only possible using a square, or rectangular, lattice, and not the graphene-like structures more commonly used in valleytronics. To achieve this effect, the two mirror symmetries, present within all fully-symmetric square structures, are broken; this leads to two nondistinct interfaces upon which valley-Hall states reside. These interfaces are related to each other via the time-reversal operator and it is this subtlety that allows us to ignite the third outgoing lead.

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We present a design for an omnidirectional transformation-optics (TO) cloak comprising thin lenses and glenses (generalized thin lenses) [J. Opt. Soc.

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We study the ray optics of generalized lenses (glenses), which are ideal thin lenses generalized to have different object- and image-sided focal lengths, and the most general light-ray-direction-changing surfaces that stigmatically image any point in object space to a corresponding point in image space. Gabor superlenses [UK patent541,753 (1940); J. Opt.

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Survival data on female invasive breast cancer with 9-year follow-up from five French cancer registries were analysed by logistic regression for prognostic factors of cancer stage. The Kaplan-Meier method and log-rank test were used to estimate and compare the overall survival probability at 5 and 7 years, and at the endpoint. The Cox regression model was used for multivariate analysis.

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Background: Few population-based studies have reported jointly analyses of relative survival according to the following prognostic factors: tumour-node-metastasis (TNM) stage, age, number of examined and positive nodes, hormonal status, histological Scarff, Bloom and Richardson (SBR) grade, tumour extension, hormone receptor status and tumour multifocal status.

Patients And Methods: Data on female invasive breast cancer were provided by the Cote d'Or breast cancer registry. The Kaplan-Meier method and log-rank test were used to estimate and compare the survival probability at 1, 5, 10 and 15 years.

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We analysed the 5-year relative survival among 4473 breast cancer cases diagnosed in 1990-1992 from cancer registries in Estonia, France, Italy, Spain, the Netherlands and the UK. Among eight categories based on ICD-O codes (infiltrating ductal carcinoma, lobular plus mixed carcinoma, comedocarcinoma, 'special types', medullary carcinoma, not otherwise specified (NOS) carcinoma, other carcinoma and cancer without microscopic confirmation), the 5-year relative survival ranged from 66% (95% CI 61-71) for NOS carcinoma to 95% (95% CI 90-100) for special types (tubular, apocrine, cribriform, papillary, mucinous and signet ring cell); 27% (95% CI 18-36) for cases without microscopic confirmation. Differences in 5-year relative survival by tumor morphology and hormone receptor status were modelled using a multiple regression approach based on generalised linear models.

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Unlabelled: The aim of our study was to evaluate and compare in thyroid cancer patients the predictive value for disease progression of thyroglobulin (Tg) levels measured under thyroid-stimulating hormone (TSH) stimulation, in the postoperative period just before (131)I ablative therapy and at the time of control 6-12 mo later.

Methods: Two-hundred twelve consecutive patients treated for a well-differentiated thyroid carcinoma (184 papillary, 28 follicular) with no initial distant metastases were retrospectively studied. All patients had a total or near-total thyroidectomy followed by ablation with 3.

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Background: Breast carcinoma survival rates were found to be higher in the U.S. than in Europe.

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Our objectives were to evaluate the effectiveness of cervical cancer screening outside organized programs in the prevention of cervical carcinoma in situ (CIS) and to enhance the way in which case control studies avoid some common biases. In our case-control study, we assessed all incident, histologically verified cases of CIS registered from 1987 to 1997 in the population-based cancer registry of C te-d'Or, France (N = 104) and 208 controls randomly selected from the screened population and matched for age, date of last screening, residence, and pathology laboratory results. We considered as appropriate for controls screened women who had had at least one Papanicolaou smear in the 3 years preceding the diagnosis or similar period.

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Purpose: The aim of the study was to determine the predictive factors of complications, to evaluate the impact of customized treatment planning on late normal tissue effects per stage, and to report disease-free survival (DFS) and local control (LC) rates.

Methods And Materials: From 1970 to 1994, 642 patients were treated with radiotherapy alone for carcinoma of the intact uterine cervix. According to the International Federation of Gynecology and Obstetrics (FIGO) substaging, 34% were Stage I, 39% Stage II, and 27% Stage III.

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Purpose: To quantify the risk of acute leukemia after adjuvant therapy, especially chemotherapy with topoisomerase II inhibitors.

Patients And Methods: We performed a population-based study in a cohort of 3,093 women younger than 85 years who resided in the French administrative area of the Côte d'Or, who were given a first diagnosis of primary breast cancer between 1982 and 1996, and who received a curative treatment. Information about therapy and follow-up events was obtained from records of cancer registries that covered this area.

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In France, as in several other European countries, prevalence has to be estimated from the modelling of 2 of the 3 basic epidemiological measures of incidence, mortality, and survival. Since, in these countries, follow-up of cancer patients is only made in a few registries, we explored the feasibility of estimating prevalence in the absence of follow-up data. The method, which used only incidence and mortality, was validated on Danish data and applied to France.

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Using the 2,208 non metastatic breast cancer diagnosed women who underwent breast surgery from the 2,432 first breast cancers recorded by the French département of Côte-d'Or cancer registry from 1982 to 1992, we described in this well-defined population, the trend in breast-cancer adjuvant treatment, and related practices with recommendations according to risk groups. Adjuvant treatment was received by 44.1% of the 2,208 women.

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Study Objective: In many countries, cancer registries cover only a small part of the national population. Cancer incidence for the rest of the country has therefore to be estimated. This can be done from mortality data using the relation between incidence and mortality observed in the cancer registry areas.

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Objectives: To conduct a survey of the angiosarcomas developing after breast conservation for carcinoma in the French Cancer Centers, to study the evolution of these cases in detail, and to review literature in an attempt to propose an optimal treatment scheme.

Material And Methods: Eleven of the 20 French Cancer Centers agreed to research and retrospectively analyze all angiosarcomas discovered in patients previously treated by conservative treatment. The majority of the patients were node negative, T1N0M0.

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Purpose: The aim of this study was to describe the implication of the different health care structures in the treatment of breast cancer.

Methods: In Côte-d'Or, from 1982 to 1992, there were 2432 cases of breast cancer. Surgery came first as treatment for 93% of the patients, radiotherapy came second (77%).

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The aim of the study was to assess the incident number of female breast and genital tract cancers for the whole of France. The study focused on the 1983-1987 period and on 9.1% of the French population.

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TP53 abnormalities have been reported as an early event in the process of cellular transformation of human breast cancers, and involved in mammary-tumor evolution, from in situ to invasive disease. In this study, node-negative (N-) tumors were examined for TP53 allelic loss in relation to different genetic instability events, including allelic loss at chromosome 17p13.3 and c-H-ras-1 loci, as well as alteration of the c-myc and c-erbB-2/neu oncogenes.

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From 1970 to 1994, 642 patients with carcinomas of intact uterine cervix were treated with radiotherapy alone Univariate and multivariate analysis was carried out of predictive factors for: 1) pelvic control and survival rates; 2) complications using French-Italian Syllabus, combined with an evaluation of the impact of customized treatment planning policy (CTP) on G3-G4. According to Figo substaging 30% of patients were stage I, 42% stage II and 28% stage III/IV. Diameter of cervical disease was 3-5 cm in 38% of cases and > 5 cm in 15%.

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