24 research outputs found
Transient perturbative nonlinear responses of plasmonic materials
Recent investigations on optical nonlinearities of plasmonic materials
suggest their responses may be even beyond the usual perturbative description.
To better understand these surprisingly strong responses, we develop here a
simple but general approach to describe the nonlinear optical response of
plasmonic materials up to th perturbation order. We apply the approach to
understand spectral broadening occurring in resonant metasurfaces and
investigate the enhancement of high-harmonic generation from multiply-resonant
metasurfaces, predicting an over million-fold enhancement of higher harmonics.Comment: 6 pages, 2 figure
Thermal Control of Plasmonic Surface Lattice Resonances
Plasmonic metasurfaces exhibiting collective responses known as surface
lattice resonances (SLRs) show potential for realizing tunable and flat
photonic components for wavelength-selective processes, including lasing and
optical nonlinearities. However, post-fabrication tuning of SLRs remains
challenging, limiting the applicability of SLR-based components. Here, we
demonstrate how the properties of high quality factor SLRs are easily modified
by breaking the symmetry of the nanoparticle surroundings. We break the
symmetry by changing the refractive index of the overlying immersion oil simply
by controlling the ambient temperature of the device. We show that already
modest temperature changes of 10{\deg}C can increase the quality factor of the
investigated SLR from 400 to 750. Our results demonstrate accurate and
reversible modification of the properties of the SLRs, paving the way towards
tunable SLR-based photonic devices. On a more general level, our results
demonstrate how symmetry breaking of the surrounding dielectric environment can
be utilized for efficient and potentially ultrafast modification of the SLR
properties
Evaluation of Long-term LiDAR Place Recognition
We compare a state-of-the-art deep image retrieval and a deep place recognition method for place recognition using LiDAR data. Place recognition aims to detect previously visited locations and thus provides an important tool for navigation, mapping, and localisation. Experimental comparisons are conducted using challenging outdoor and indoor datasets, Oxford Radar RobotCar and COLD, in the "long-term" setting where the test conditions differ substantially from the training and gallery data. Based on our results the image retrieval methods using LiDAR depth images can achieve accurate localization (the single best match recall 80%) within 5.00 m in urban outdoors. In office indoors the comparable accuracy is 50 cm but is more sensitive to changes in the environment.acceptedVersionPeer reviewe
Psychiatric disorders are a common prognostic marker for worse outcome in patients with idiopathic intracranial hypertension
Objective Idiopathic intracranial hypertension (IIH) is aetiologically unknown disorder that associates with endocrinological disturbances, including dysfunction of hypothalamic-pituitary-adrenal-axis. Neuroendocrinological dysfunctions have also been characterized in psychiatric disorders, and therefore we investigated the presence of psychiatric disorders of patients with IIH in a well-defined cohort. Patients and Methods A total of 51 patients with IIH were included. Patient demographics, symptoms, imaging data, ophthalmological and clinical findings were collected. Results At the time of diagnosis the mean age was 32.5years (SD 10.7), the body mass index was 37.1 kg/m2 (SD 7.4), and the opening pressure 29.1 mmHg (SD 6.2). A total of 88.2% of patients were female and 45.1% were diagnosed with a psychiatric co-morbidity prior to IIH diagnosis. The mean follow-up time was 4.4 years (SD 5.4). The overall treatment outcome was significantly poorer on a group of patients with psychiatric diagnosis when compared to individuals without such history (p = 0.001), but there were no differences in the resolution of papilledema (p = 0.405). Patients with IIH and psychiatric disorders had more often empty sella on their imaging at diagnosis when compared to patients without psychiatric co-morbidity (p = 0.044). Conclusion Psychiatric disorders are highly prevalent in patients with IIH and associate with worse subjective outcomes. These findings advocate for monitoring the mental health of patients with IIH and warrant further multidisciplinary research to understand the potentially underlying psychosocial and neuroendocrinological mechanisms.Peer reviewe
Adipose Tissue Omega-3 and Omega-6 Fatty Acid Content and Breast Cancer in the EURAMIC Study
The fatty acid content of adipose tissue in postmenopausal breast cancer cases and controls from five European countries in the European Community Multicenter Study on Antioxidants, Myocardial Infarction, and Cancer (EURAMIC) breast cancer study (1991 -1992) was used to explore the hypothesis that fatty acids of the omega-3 family inhibit breast cancer and that the degree of inhibition depends on background levels of omega-6 polyunsaturates. Considered in isolation, the level of omega-3 or omega-6 fat in adipose tissue displayed little consistent association with breast cancer across study centers. The ratio of long-chain omega-3 fatty acids to total omega-6 fat showed an inverse association with breast cancer in four of five centers. In Malaga, Spain, the odds ratio for the highest tertile relative to the lowest reached 0.32 (95% confidence interval 0.13-0.82). In this center, total omega-6 fatty acid was strongly associated with breast cancer. With all centers pooled, the odds ratio for long-chain omega-3 to total omega-6 reached 0.80 for the second tertile and 0.65 for the third tertile, a downward trend bordering on statistical significance (p for trend = 0.055). While not definitive, these results provide evidence for the hypothesis that the balance between omega-3 and omega-6 fat may play a rolein breast cancer. Am J Epidemiol 1998; 147: 342-5
Lycopene and Myocardial Infarction Risk in the EURAMIC Study
A multicenter case-control study was conducted to evaluate the relations between antioxidant status assessed by biomarkers and acute myocardial infarction. Incidence cases and frequency matched controls were recruited from 10 European countries to maximize the variance in exposure within the study. Adipose tissue needle aspiration biopsies were taken shortly after the infarction and analyzed for levels of carotenoids and tocopherols. An examination of colinearity including all covariates and the three carotenoids, α-carotene, β-carotene, and lycopene, showed that the variables were sufficiently independent to model simultaneously. When examined singularly, each of the carotenoids appeared to be protective. Upon simultaneous analyses of the carotenoids, however, using conditional logistic regression models that controlled for age, body mass index, socioeconomic status, smoking, hypertension, and maternal and paternal history of disease, lycopene remained independently protective, with an odds ratio of 0.52 for the contrast of the 10th and 90th percentiles (95% confidence interval 0.33-0.82, p= 0.005). The associations for α- and β-carotene were largely eliminated. We conclude that lycopene, or some substance highly correlated which is in a common food source, may contribute to the protective effect of vegetable consumption on myocardial infarction ris
Association Between Toenail Selenium and Risk of Acute Myocardial Infarction in European Men: The EURAMIC Study
The association between selenium status and risk of acute myocardial infarction was examined in a multicenter case-control study in 10 centers from Europe and Israel in 1991-1992. Selenium in toenails was assessed for 683 nonfatal male cases with first acute myocardial infarction and 729 controls less than 70 years of age. Median toenail selenium content was 0.553 ÎĽg/g for cases and 0.590 ÎĽg/g for controls. After adjustment for age, center, and smoking, the odds ratio for myocardial infarction in the highest quintile of selenium as compared with the lowest was 0.63 . The observed inverse trend was somewhat stronger when the authors adjusted for vitamin E status (p = 0.05). Analysis stratified for smoking habits showed an inverse association in former smokers (odds ratio for the 75th-25th percentile contrast = 0.63 (95 percent confidence interval 0.43-0.94)), but not in current smokers (odds ratio = 0.97 ( 0.71-1.32)) or in those who had never smoked (odds ratio = 1.55 (0.87-2.76)). Analysis stratified by center showed a significant inverse association between selenium levels and risk of myocardial infarction for Germany (Berlin) only (75th to 25th percentile odds ratio = 0.62 (95 percent confidence interval 0.42-0.91)), which was the center with the lowest selenium levels. It appears that the increased risk of acute myocardial infarction at low levels of selenium intake is largely explained by cigarette smoking; selenium status does not appear to be an important determinant of risk of myocardial infarction at the levels observed in a large part of Europe. Am J Epidemiol 1997; 145: 373-
Role of psychosocial factors on treatment outcome of temporomandibular disorders
Abstract
Objectives: The aim of this randomized controlled study was to investigate the effect of depressive and non-specific physical symptoms on treatment outcome of temporomandibular disorders (TMD).
Material and methods: Eighty TMD patients were randomly assigned to splint group (n = 39) and control group (n = 41). The patients were classified in terms of depressive and non-specific physical symptoms as normal, moderate or severe using Research Diagnostic Criteria for Temporomandibular Disorders Axis II protocol. The effect of depressive and non-specific physical symptoms on the intensity of facial pain, as measured with visual analogue scale (VAS) was estimated with linear mixed models. The patients’ subjective estimates of the effects of treatment and TMD symptom severity were inquired at 1-year follow-up.
Results: At baseline and during the follow-up there were no significant differences in VAS scores between patients in different Axis II subscales. According to the mixed linear regression, depressiveness or nonspecific physical symptoms separately were not significantly associated with the VAS during the study. The association of VAS with depressive (p = .073) and nonspecific physical symptoms (p = .088) approximated statistical significance. Patients with moderate or severe nonspecific physical symptoms (with pain items) at baseline had more frequently moderate, severe or intolerable TMD symptoms after the treatment compared to those who were classified in normal subgroup.
Conclusions: The present study gave some indication of a possible negative effect of depressive and nonspecific physical symptoms (with pain items) on TMD treatment response. However, the results should be regarded as preliminary, and further studies with larger sample size are needed to confirm the results