32 research outputs found
Generation and subwavelength focusing of longitudinal magnetic fields in a metallized fiber tip
We demonstrate experimentally and numerically that in fiber tips as they are
used in NSOMs azimuthally polarized electrical fields
(|E|/|E| 55% 5% for
1.4\mu m tip aperture diameter and \lambda = 1550nm), respectively
subwavelength confined (FWHM 450nm \lambda/3.5)
magnetic fields, are generated for a certain tip aperture diameter (d = 1.4\mu
m). We attribute the generation of this field distribution in metal-coated
fiber tips to symmetry breaking in the bend and subsequent plasmonic mode
filtering in the truncated conical taper.Comment: 11 pages, 6 figure
Фазогенераторная схема с индуктивно-емкостной связью между контурами
Рассматривается теория фазогенераторной схемы с индуктивно-емкостной связью, образованной взаимной индуктивностью полуобмоток дифференциального проходного вихретокового преобразователя и емкостью конденсатора связи, настроенного в резонанс с эквивалентной взаимной индуктивностью. Дается вывод аналитических выражений для определения рабочей частоты, емкости конденсатора связи, чувствительности фазогенераторной схемы. Теоретические выводы подтверждаются результатами экспериментов
Functional plasmonic nanocircuits with low insertion and propagation losses
We experimentally demonstrate plasmonic nanocircuits operating as subdiffraction directional couplers optically excited with high efficiency from free-space using optical Yagi-Uda style antennas at λ_0 = 1550 nm. The optical Yagi-Uda style antennas are designed to feed channel plasmon waveguides with high efficiency (45% in coupling, 60% total emission), narrow angular directivity (<40°), and low insertion loss. SPP channel waveguides exhibit propagation lengths as large as 34 μm with adiabatically tuned confinement and are integrated with ultracompact (5 × 10 μm^2), highly dispersive directional couplers, which enable 30 dB discrimination over Δλ = 200 nm with only 0.3 dB device loss
Negative refraction due to discrete plasmon diffraction
We experimentally demonstrate spectrally broad (λ_0=1200-1800 nm) in-plane negative diffraction of SPPs in an array of plasmonic channel waveguides with negative mutual coupling resulting in negative refraction on the array's interface and refocusing in an adjacent metal layer
Assessing a risk tailored intervention to prevent disabling low back pain - protocol of a cluster randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Although most patients with low back pain (LBP) recover within a few weeks a significant proportion has recurrent episodes or will develop chronic low back pain. Several mainly psychosocial risk factors for developing chronic LBP have been identified. However, effects of preventive interventions aiming at behavioural risk factors and unfavourable cognitions have yielded inconsistent results. Risk tailored interventions may provide a cost efficient and effective means to take systematic account of the individual risk factors but evidence is lacking.</p> <p>Methods/Design</p> <p>This study will be a cluster-randomised controlled trial comparing screening and a subsequent risk tailored intervention for patients with low back pain to prevent chronic low back pain compared to treatment as usual in primary care. A total of 600 patients from 20 practices in each study arm will be recruited in Berlin and Goettingen. The intervention comprises the following elements: Patients will be assigned to one of four risk groups based on a screening questionnaire. Subsequently they receive an educational intervention including information and counselling tailored to the risk group. A telephone/email consulting service for back pain related problems are offered independent of risk group assignment. The primary outcomes will be functional capacity and sick leave.</p> <p>Discussion</p> <p>This trial will evaluate the effectiveness of screening for risk factors for chronic low back pain followed by a risk tailored intervention to prevent chronic low back pain. This trial will contribute new evidence regarding the flexible use of individual physical and psychosocial risk factors in general practice.</p> <p>Trial registration</p> <p>ISRCTN 68205910</p
The development of spontaneous facial responses to others’ emotions in infancy. An EMG study
Viewing facial expressions often evokes facial responses in the observer. These spontaneous facial reactions (SFRs) are believed to play an important role for social interactions. However, their developmental trajectory and the underlying neurocognitive mechanisms are still little understood. In the current study, 4- and 7-month old infants were presented with facial expressions of happiness, anger, and fear. Electromyography (EMG) was used to measure activation in muscles relevant for forming these expressions: zygomaticus major (smiling), corrugator supercilii (frowning), and frontalis (forehead raising). The results indicated no selective activation of the facial muscles for the expressions in 4-month-old infants. For 7-month-old infants, evidence for selective facial reactions was found especially for happy faces (leading to increased zygomaticus major activation) and fearful faces (leading to increased frontalis activation), while angry faces did not show a clear differential response. This suggests that emotional SFRs may be the result of complex neurocognitive mechanisms which lead to partial mimicry but are also likely to be influenced by evaluative processes. Such mechanisms seem to undergo important developments at least until the second half of the first year of life
'ProSens' - Integrated production control by automated inspection planning and efficient multisensor metrology
By China's entry into the WTO, chinese as well as german companies are facing the question, how to minimise the risk of unfamiliar co-operation partners when developing products. The rise of customer demands concerning quality, product diversity and the reduction of expenses require flexibility and efficiency with reliable component suppliers. In order to build and strengthen sino-german co-operations, a manufacturing control using homogenised and efficient measures to assure high quality is of vital importance. Lack of unifications may cause identical measurements conducted at subcontractors or customers to be carried out with different measurement processes which leads to incomparable results. Rapidly growing company cooperations and simultaneously decreasing of manufacturing scope cause substantial difficulties when coordinating joint quality control activities. “ProSens”, a sino-german project consortium consisting of industrial users, technology producers and research institutes, aims at improving selected production processes by: - Creation of a homogeneous quality awareness in sino-german co-operations - Sensitisation for process accompanying metrology at an early stage of product development - Increase of the process performance by the use of integrated metrology - Reduction of production time and cost Unification of quality control of complex products by means of efficient measurement strategies and CAD-based inspection planning
Classification, incidence and survival analyses of children with CNS tumours diagnosed in Sweden 1984-2005
Aim: Primary tumours in the central nervous system (CNS) are the second most common malignancy in childhood after leukaemia. Sweden has a high incidence and a high-survival rate in international comparative studies. This has raised the question about the type of tumours included in the Swedish Cancer registry. We therefore compared international data to the Swedish Childhood Cancer registry. Methods: Central nervous system tumours registered in the Swedish Childhood Cancer Registry were reclassified according to ICCC-3. Incidence and survival analyses were performed in the study population. Results: There were 1479 children (< 15 years) in Sweden diagnosed with CNS tumours 1984-2005. The distribution of diagnoses was similar to that reported in other studies. The annual incidence was 4.2/100 000 children. The survival rates have not improved significantly between the two time periods before/after 1995 (70% vs. 74%; p = 0.10). Conclusions: The mean annual incidence of children with CNS tumours was 4.2/100 000 and has not increased during the study period. Survival rate for brain tumours at 10 years follow-up was 72%