212 research outputs found

    Optical response of silver nanoneedles on a mirror

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    Plasmonic properties of metal nanostructures are appealing due to their potential to enhance photovoltaics or sensing performance. Our aim was to identify the plasmonic characteristics of silver nanoneedles on a reflective layer in the polarized optical response. Experimental ellipsometry results are complemented by finite-difference time-domain (FDTD) calculations. Plasmon resonances on the nanoneedles can indeed be observed in the polarized optical response. This study reveals the details of the complex antenna-like behaviour of the nanoneedles which gives an agreement between experiment and FDTD simulation. The simulations show that the plasmon resonances lead to an effective negative refractive index, originating from the negative refractive index of the nanoneedles in combination with its supporting substrate, i.e. a mirror. This original study of a complex plasmonic system by ellipsometry and FDTD has great relevance for applications, making use of intricate light matter interaction

    Драматичні елементи у фольклорі – традиція та актуальність

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    The researches of the folklore and ethnographic sources underscore, that the dramatic elements exist in the folk art (songs, fairy tales, small folklore genres, children folklore etc.), in customs and in the other forms of the life of the folk. But it's importaint what I mean by the notion "dramatic elements in the folklore". Namely, existence of the action, plot, culmination and denouement, then the place and time of the development of the action, monologue, dialogue in the action, characters, masks, dresses, text, scenography, scenario, director, audience, puppet-show, i. e. the presence of the performance. In this paper special attention is given to some dramatic acting with multitude of the dramatic elements, which are connected with large quantity of the Cristmas holidays. We also drew parallels between traditional forms and new elements of celebration and results of the actualization of some innovations in society. It is worth to refer the carnivals in Vechani and Strumitsa and also celebrations of the Eve in Skopje

    Effectiveness of high-intensity interval training for weight loss in adults with obesity: A randomised controlled non-inferiority trial

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    Introduction Obesity treatment guidelines suggest moderate-intensity continuous training (MICT), but the patient's compliance to this indication remains low. High-intensity interval training (HIIT) is a time sparing training mode whose metabolic effects are not clear. This study aimed to determine whether a 12-week HIIT was more effective than MICT for weight loss in obese adults. Methods 44 obese subjects were randomised and trained with isoenergetic treadmill exercises for 12 weeks: MICT (60% of maximal oxygen peak, VO 2 peak) or HIIT (3-7 repetition of 3 min 100% of VO 2 peak interspersed by 1.5 min 50% of VO 2 peak). The primary outcome was a change in body weight; the secondary outcomes were changes in body composition, blood pressure, lipid profile, glycaemia, insulin and VO 2 peak. Results 32 subjects (53% male, mean age: 38.5 years, mean body mass index: 35.5 kg/m 2) completed the trial. MICT and HIIT showed comparable effect within groups in weight loss (-6.0 kg (-9.0 kg to -3.0 kg) vs -5.7 kg (-8.3 kg to -3.1 kg)), changes in fat mass (-2.9% (-4.4% to -1.4%) vs -3.6% (-5.9% to -1.2%)), fat free mass (-5.3% (-7.8% to -2.8%) vs -5.5% (-8.3% to -2.6%)), diastolic blood pressure (-5.5 mm Hg (-10.6 mm Hg to -0.3 mm Hg) vs -5.8 mm Hg (-11.3 mm Hg to -0.3 mm Hg)) and low-density lipoprotein cholesterol (-16.4 mg/dL (-30.8 mg/dL to -2.0 mg/dL) vs -14.7 mg/dL (-25.6 mg/dL to -3.8 mg/dL)). There was a significant change between groups in VO 2 peak (HIIT: +461.6 mL (329.3a \u20ac'593.8 mL); MICT: +170.5 mL (86.7-254.4 mL); p<0001) and duration of sessions (HIIT: 35.0 min (31.7 a \u20ac'35.6 min); MICT: 46.5 min (40.2a \u20ac'48.3 min); p<0.001). No significant changes in systolic blood pressure, high-density lipoprotein cholesterol, triglycerides, glycaemia or plasma insulin were observed. Conclusions In healthy adults with obesity, HIIT compared with MICT induced similar weight loss and cardiovascular risk factors improvement but resulted in a larger increase in cardiorespiratory fitness over a shorter period

    Luminescent tracks of high-energy photoemitted electrons accelerated by plasmonic fields

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    The emission of an electron from a metal nanostructure under illumination and its subsequent acceleration in a plasmonic field forms a platform to extend these phenomena to deposited nanoparticles, which can be studied by state-of-the-art confocal microscopy combined with femtosecond optical excitation. The emitted and accelerated electrons leave defect tracks in the immersion oil, which can be revealed by thermoluminescence. These photographic tracks are read out with the confocal microscope and have a maximum length of about 80 \u3bcm, which corresponds to a kinetic energy of about 100 keV. This energy is consistent with the energy provided by the intense laser pulse combined with plasmonic local field enhancement. The results are discussed within the context of the rescattering model by which electrons acquire more energy. The visualization of electron tracks originating from plasmonic field enhancement around a gold nanoparticle opens a new way to study with confocal microscopy both the plasmonic properties of metal nano objects as well as high energy electron interaction with matter

    The role of vitamin D in male fertility: A focus on the testis

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    In the last decade, vitamin D has emerged as a pleiotropic molecule with a multitude of autocrine, paracrine and endocrine functions, mediated by classical genomic as well as non-classical non-genomic actions, on multiple target organs and systems. The expression of vitamin D receptor and vitamin D metabolizing enzymes in male reproductive system, particularly in the testis, suggests the occurrence of vitamin D synthesis and regulation as well as function in the testis. The role of vitamin D in the modulation of testis functions, including hormone production and spermatogenesis, has been investigated in animals and humans. Experimental studies support a beneficial effect of vitamin D on male fertility, by modulating hormone production through genomic and non-genomic actions, and, particularly, by improving semen quality essentially through non-genomic actions. However, clinical studies in humans are controversial. Indeed, vitamin D seems to contribute to the modulation of the bioavailable rather than total testosterone. Moreover, although an increased prevalence or risk for testosterone deficiency was reported in men with vitamin D deficiency&nbsp;in observational studies, the majority of interventional studies demonstrated the lack of effect of vitamin D supplementation on circulating levels of testosterone. The most consistent effect of vitamin D was reported on semen quality. Indeed, vitamin D was shown to be positively associated to sperm motility, and to exert direct actions on spermatozoa, including non-genomic driven modulation of intracellular calcium homeostasis and activation of molecular pathways involved in sperm motility, capacitation and acrosome reaction. The current review provides a summary of current knowledge on the role of vitamin D in male fertility, by reporting clinical and experimental studies in humans and animals addressing the relationship between vitamin D and testis function

    Creation and luminescence of size-selected gold nanorods

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    Fluorescent metal nanoparticles have attracted great interest in recent years for their unique properties and potential applications. Their optical behaviour depends not only on size but also on shape, and will only be useful if the morphology is stable. In this work, we produce stable size-selected gold nanorods (aspect ratio 1-2) using a size-selected cluster source and correlate their luminescence behaviour with the particle shape. Thermodynamic modelling is used to predict the preferred aspect ratio of 1.5, in agreement with the observations, and confirms that the double-icosahedron observed in experiments is significantly lower in energy than the alternatives. Using these samples a fluorescence lifetime imaging microscopy study observed two photon luminescence from nanoparticle arrays and a fast decay process (<100 ps luminescence lifetime), which are similar to those found from ligand stabilized gold nanorods under the same measurement conditions, indicating that a surface plasmon enhanced two-photon excitation process is still active at these small sizes. By further reducing the nanoparticle size, this approach has the potential to investigate size-dependent luminescence behaviour at smaller sizes than has been possible before

    Optical properties of MgH2 measured in situ in a novel gas cell for ellipsometry/spectrophotometry

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    The dielectric properties of alpha-MgH2 are investigated in the photon energy range between 1 and 6.5 eV. For this purpose, a novel sample configuration and experimental setup are developed that allow both optical transmission and ellipsometric measurements of a transparent thin film in equilibrium with hydrogen. We show that alpha-MgH2 is a transparent, colour neutral insulator with a band gap of 5.6 +/- 0.1 eV. It has an intrinsic transparency of about 80% over the whole visible spectrum. The dielectric function found in this work confirms very recent band structure calculations using the GW approximation by Alford and Chou [J.A. Alford and M.Y. Chou (unpublished)]. As Pd is used as a cap layer we report also the optical properties of PdHx thin films.Comment: REVTeX4, 15 pages, 12 figures, 5 table

    Dietary total antioxidant capacity and colorectal cancer in the Italian EPIC cohort

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    Background Colorectal cancer is the third most common cancer worldwide. Diet has been hypothesized as involved in colorectal cancer etiology, but few studies on the influence of total dietary antioxidant intake on colorectal cancer risk have been performed. Methods We investigated the association between colorectal cancer risk and the total antioxidant capacity (TAC) of the diet, and also of intake of selected antioxidants, in 45,194 persons enrolled in 5 centers (Florence, Naples, Ragusa, Turin and Varese) of the European Prospective Investigation into Cancer and Nutrition (EPIC) Italy study. TAC was estimated by the Trolox equivalent antioxidant capacity (TEAC) assay. Hazard ratios (HRs) for developing colorectal cancer, and colon and rectal cancers separately, adjusted for confounders, were estimated for tertiles of TAC by Cox modeling, stratifying by center. Results Four hundred thirty-six colorectal cancers were diagnosed over a mean follow-up of 11.28 years. No significant association between dietary TAC and colorectal cancer incidence was found. However for the highest category of TAC compared to the lowest, risk of developing colon cancer was lower (HR: 0.63; 95% CI: 0.44\u20130.89, P trend: 0.008). By contrast, increasing TAC intake was associated with significantly increasing risks of rectal cancer (2nd tertile HR: 2.09; 95%CI: 1.19\u20133.66; 3rd tertile 2.48 95%CI: 1.32\u20134.66; P trend 0.007). Intakes of vitamin C, vitamin E, and f-carotene were not significantly associated with colorectal cancer risk. Conclusions Further prospective studies are needed to confirm the contrasting effects of high total antioxidant intake on risk of colon and rectal cancers

    Long-Term Prognosis of Patients With Takotsubo Syndrome

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    BACKGROUND Prognosis of Takotsubo syndrome (TTS) remains controversial due to scarcity of available data. Additionally, the effect of the triggering factors remains elusive. OBJECTIVES This study compared prognosis between TTS and acute coronary syndrome (ACS) patients and investigated short- and long-term outcomes in TTS based on different triggers. METHODS Patients with TTS were enrolled from the International Takotsubo Registry. Long-term mortality of patients with TTS was compared to an age- and sex-matched cohort of patients with ACS. In addition, short- and long-term outcomes were compared between different groups according to triggering conditions. RESULTS Overall, TTS patients had a comparable long-term mortality risk with ACS patients. Of 1,613 TTS patients, an emotional trigger was detected in 485 patients (30%). Of 630 patients (39%) related to physical triggers, 98 patients (6%) had acute neurologic disorders, while in the other 532 patients (33%), physical activities, medical conditions, or procedures were the triggering conditions. The remaining 498 patients (31%) had no identifiable trigger. TTS patients related to physical stress showed higher mortality rates than ACS patients during long-term follow-up, whereas patients related to emotional stress had better outcomes compared with ACS patients. CONCLUSIONS Overall, TTS patients had long-term outcomes comparable to age- and sex-matched ACS patients. Also, we demonstrated that TTS can either be benign or a life-threating condition depending on the inciting stress factor. We propose a new classification based on triggers, which can serve as a clinical tool to predict short- and long-term outcomes of TTS. (International Takotsubo Registry [InterTAK Registry]; NCT01947621)
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