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排序方式: 共有170条查询结果,搜索用时 19 毫秒
1.
A 1534-nm fiber laser pumped Er:YAG laser action at room temperature has been demonstrated with high efficiency at two emission wavelengths: 1645 and 1617 nm. Multiwatt continuous-wave power was demonstrated at both wavelengths and active electrooptic Q-switch operation with >90% Q-switch efficiency was achieved at 1645 nm. Etalon tuned wavelength selection showed excellent agreement with theoretical analysis.  相似文献   
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The extensive use of the Unified Parkinson's Disease Rating Scale (UPDRS) has revealed low interrater reliability in some items and redundancy in others. In view of these shortcomings, we have structured a new scale that includes a zero-to three-point scale for each item in the evaluation of PD. The mental axis includes memory, thought disorders, and depression. Activities of daily living (ADL) includes eight items: speech, eating, feeding, dressing, hygiene, handwriting, walking, and turning in bed. The motor examination includes eight items: speech, tremor, rest and posture, rigidity, finger tapping, arising from chair, gait, and postural stability. Complications of therapy were also included: dyskinesias, dystonia, motor fluctuations, and freezing episodes, collected by history. In addition, a global scoring for motor fluctuations that should complement the Hoehn and Yahr Scale was incorporated. In this report, we present a statistical analysis of the ADL, motor evaluation, and complications of therapy sections. Concerning the interrater reliability mean, Kendall's W values were >0.9 for most of the items in the Short Parkinson's Evaluation Scale (SPES). Kendall's W <0.8 (motor evaluation) was found for two items of the SPES and nine items of the UPDRS. The mean interrater reliability for both scales across all seven centers (seven Kendall's W for seven centers) (Mann-Whitney test) showed no statistical differences between the scales. Spearman's correlations between items of both scales were significant. Factor analysis of the SPES and UPDRS data revealed a four-factor solution that explained approximately 60% of the data. All participating centers found the SPES easier to apply and quicker to complete, when compared with the UPDRS. The results obtained strongly favor the introduction of SPES for clinical practice.  相似文献   
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The Cu-Sn-Ti ternary system has been studied via experiments and thermodynamic modelling. In the experimental section, the composition of the alloys was selected based on the preliminary calculations and available literature data. Metallography, scanning electron microscopy and electron probe microanalysis were employed to analyse alloy samples prepared by arc-melting after annealing at 800 °C for 760 h. Solid phase relations at 800 °C were established. In contrast to earlier reports, the CuSn3Ti5 phase was interpreted as a binary intermetallic compound (Sn3Ti5) with extended Cu solubility. In the modelling section, three binary sub-systems were critically evaluated and updated according to the new experimental data and theoretical calculations reported in literature. According to their crystal structures and homogeneity ranges, appropriate sublattice models were proposed for SnTi3,SnTi2,Sn3Ti5 and Sn5Ti6. A set of self-consistent thermodynamic parameters for the Cu-Sn-Ti ternary system was obtained by considering the present experimental results and reported experimental information. The calculated results compare with the available experimental data to validate the present thermodynamic assessment.  相似文献   
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We report on a new instrument developed for rapid automated on-line and continuous measurement of ambient aerosol bulk com- position.The general approach is based on earlier devices (Khlystov et al. 1995; Simon and Dasgupta 1995) in which ambient particles are mixed with saturated water vapor to produce droplets easily collected by inertial techniques. The resulting liquid stream is analyzed with an ion chromatograph to quantitatively measure the bulk aerosol ionic components. In this instrument, a modified ver- sion of a particle size magnifier (Okuyama et al. 1984) is employed to activate and grow particles comprising the fine aerosol mass. A single jet inertial impactor is used to collect the droplets onto a vertical glass plate that is continually washed with a constant water diluent flow of nominally 0.10 ml min-1  相似文献   
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Blue and purple gold alloys form in the alloying systems of gold with gallium/indium and aluminium respectively and are known to be very brittle and to possess low corrosion resistance. Taking into account these drawbacks this paper describes the results of a European funded research project. The properties of the blue and purple gold alloys and coatings such as corrosion resistance, metal release rates, hardness and colour and the influence of alloying additions on these properties are presented and discussed. Surface engineering techniques and investment casting were used for manufacturing of jewellery items with selectively coated coloured surface. Coatings of AuGa2 and AuIn2 blue gold alloys were applied on 18kt gold and Sterling silver jewellery by electroplating, laser/torch cladding or dipping into liquid gallium. The suitability of blue gold coatings for jewellery purposes will be discussed in the light of reliability and feasibility. The work consists of two parts. Part I describes properties and surface processing techniques while Part II deals with investment casting and related alloy design of coloured gold alloys.  相似文献   
7.
Pathogenic variants in KCNA2, encoding for the voltage-gated potassium channel Kv1.2, have been identified as the cause for an evolving spectrum of neurological disorders. Affected individuals show early-onset developmental and epileptic encephalopathy, intellectual disability, and movement disorders resulting from cerebellar dysfunction. In addition, individuals with a milder course of epilepsy, complicated hereditary spastic paraplegia, and episodic ataxia have been reported. By analyzing phenotypic, functional, and genetic data from published reports and novel cases, we refine and further delineate phenotypic as well as functional subgroups of KCNA2-associated disorders. Carriers of variants, leading to complex and mixed channel dysfunction that are associated with a gain- and loss-of-potassium conductance, more often show early developmental abnormalities and an earlier onset of epilepsy compared to individuals with variants resulting in loss- or gain-of-function. We describe seven additional individuals harboring three known and the novel KCNA2 variants p.(Pro407Ala) and p.(Tyr417Cys). The location of variants reported here highlights the importance of the proline(405)–valine(406)–proline(407) (PVP) motif in transmembrane domain S6 as a mutational hotspot. A novel case of self-limited infantile seizures suggests a continuous clinical spectrum of KCNA2-related disorders. Our study provides further insights into the clinical spectrum, genotype–phenotype correlation, variability, and predicted functional impact of KCNA2 variants.  相似文献   
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