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排序方式: 共有1021条查询结果,搜索用时 15 毫秒
91.
Improving the frame-error-rate of spatial multiplexing in block fading by randomly rotating the signal constellation 总被引:1,自引:0,他引:1
We demonstrate that one can improve the coded frame-error-rate of spatial multiplexing in block fading by randomly rotating the signal constellation. Unlike linear precoding, our method: 1) does not require coding over time and 2) brings a performance improvement at essentially no additional computational expense. A discussion of the results is provided. 相似文献
92.
Bjorn M. Ludvigsson Stig R. Larsson 《JOM Journal of the Minerals, Metals and Materials Society》2003,55(4):41-44
There are numerous approaches to the treatment of both copper and lead anode slimes. Although the chemistry and metallurgy
has been described and discussed by many authors, few, if any, have described the environmental impact of these activities.
Dust and especially selenium emissions are a problem both in the internal working environment as well as in the external environment.
For more information, contact B.M. Ludvigsson, Boliden Contech AB, P.O. Box 745 Skelleftea 93127, Sweden; e-mail bjorn.ludvigsson@contech.boliden.se. 相似文献
93.
The mortality and causes of death in 115 patients (80 women), born 1902-1937, with untreated scoliosis were compared to the expected according to official Swedish statistics. Subgrouping for cause and onset of scoliosis was done. Fifty-five patients had died; 21 of respiratory failure and 17 of cardiovascular diseases. The mortality was significantly (P less than 0.001) increased. The increased risk was apparent at 40-50 years of age. The mortality was significantly increased in infantile (P less than 0.001) and juvenile (P less than 0.01) scoliosis but not in adolescent scoliosis. The mortality was also increased in post-polio scoliosis, scoliosis combined with rickets and scoliosis of unknown etiology indicating an increased mortality in idiopathic scoliosis. Among the surviving patients anti-hypertensive treatment was frequent (23 of 50). 相似文献
94.
95.
Aarts HJ Vos P Larsson JT van Hoek AH Huehn S Weijers T Grønlund HA Malorny B 《International journal of food microbiology》2011,145(Z1):S68-S78
A proof of principle of a multi-target assay for genotyping Salmonella has been developed targeting 62 genomic marker sequences of Salmonella related to pathogenicity. The assay is based on multiplex ligation detection reaction (LDR) followed by customized ArrayTube? microarray detection. The feasibility of the developed assay was verified in a method comparison study with conventional PCR using 16 Salmonella 'test' strains comprising eight serovars. Subsequently, the feasibility of the LDR microarray assay was also tested by analyzing 41 strains belonging to 23 serovars. With the exception of four serovars each serovar was characterized by a unique virulence associated gene repertoire. The LDR microarray platform proved to be a convenient, rapid and easy to use tool with potential in tracing a Salmonella contamination in the food chain, for outbreak studies, and to provide data for risk assessors that support bio-traceability models. 相似文献
96.
Anders O. Larsson Michael Hultstrm Robert Frithiof Miklos Lipcsey Mats B. Eriksson 《International journal of molecular sciences》2022,23(24)
A selective decrease in the renal filtration of larger molecules is attributed to the shrinkage of glomerular pores, a condition termed Shrunken Pore Syndrome (SPS). SPS is associated with poor long-term prognosis. We studied SPS as a risk marker in a cohort of patients with COVID-19 treated in an intensive care unit. SPS was defined as a ratio < 0.7 when the estimated glomerular filtration rate (eGFR), determined by cystatin C, calculated by the Cystatin C Caucasian-Asian-Pediatric-Adult equation (CAPA), was divided by the eGFR determined by creatinine, calculated by the revised Lund–Malmö creatinine equation (LMR). Clinical data were prospectively collected. In total, SPS was present in 86 (24%) of 352 patients with COVID-19 on ICU admission. Patients with SPS had a higher BMI, Simplified Physiology Score (SAPS3), and had diabetes and/or hypertension more frequently than patients without SPS. Ninety-nine patients in the total cohort were women, 50 of whom had SPS. In dexamethasone-naïve patients, C-reactive protein (CRP ), TNF-alpha, and interleukin-6 did not differ between SPS and non-SPS patients. Demographic factors (gender, BMI) and illness severity (SAPS3) were independent predictors of SPS. Age and dexamethasone treatment did not affect the frequency of SPS after adjustments for age, sex, BMI, and acute severity. SPS is frequent in severely ill COVID-19 patients. Female gender was associated with a higher proportion of SPS. Demographic factors and illness severity were independent predictors of SPS. 相似文献
97.
Holmberg A Fogel J Albertsson E Fick J Brown JN Paxéus N Förlin L Johnsson JI Larsson DG 《Journal of hazardous materials》2011,187(1-3):596-599
Citalopram is one of several selective serotonin reuptake inhibitors (SSRIs) commonly found in treated sewage effluents. Accordingly, there are concerns about possible adverse effects of SSRIs on aquatic organisms, particularly behavioural effects similar to those associated with SSRI use in humans. Rainbow trout fry and adult male guppies were therefore exposed to waterborne citalopram, ranging from environmentally relevant to high concentrations (1, 10, 100 μg/L) for 3-7 days. Under these experimental conditions citalopram does not appear to cause significant effects on aggression in rainbow trout fry or on sexual behaviour in male guppies. This may be explained by a relatively low uptake of citalopram from water to fish. 相似文献
98.
99.
The purpose of this study was to investigate the effects of a 6-week period without weight bearing, achieved by bed rest, on the contractile behaviour, myosin isoform expression and myofibrillar protein content of single human muscle fibres. Percutaneous biopsied specimens of the quadriceps muscle were taken from three healthy male volunteers before and at the end of the experimental period. Maximum force normalised to cross-sectional area (specific tension), maximum velocity of unloaded shortening (V0), and myosin heavy chain (MyHC) and light chain (MyLC) isoform composition were measured in single membrane-permeabilised muscle cells obtained from these specimens. At the end of the experimental period, specific tension was reduced (P < 0.001) by 40% and there was a parallel decline in myofibrillar protein content per muscle cell volume. V0 did not change significantly in response to bed rest when data from all muscle cells were pooled. In two of the subjects, however, V0 decreased (P < 0.01-0.001) in muscle cells expressing the beta/slow (type I) MyHC isoform, but there was no change in fibres expressing type IIA or a combination of type IIA and IIB MyHCs. The slowing in type I MyHC fibres was associated with a change in the isoform composition of the regulatory MyLC. 相似文献
100.
Acidianus brierleyi was demonstrated to remove pyritic sulphur from coal. A. brierleyi was also found capable of catalyzing the removal of what is normally reported as organic sulphur from coal 171US34. A kinetic analysis was performed by assuming a first order reaction. The first order kinetics allowed a comparison with literature data for Thiobacillus ferrooxidans. Also, formation of jarosite was taken into account in the analysis. The simple first order kinetics was observed to fit the data on removal of sulphur satisfactorily. 相似文献