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1.
The isolation and characterization of bacteriophages infecting obligately thermophilic strains of Bacillus 总被引:2,自引:0,他引:2
R J Sharp S I Ahmad A Munster B Dowsett T Atkinson 《Journal of general microbiology》1986,132(6):1709-1722
Twenty-four thermophilic bacteriophages have been isolated from diverse sources such as compost, soil, silage and rotting straw. Although considerable individual host specificity was observed, the phages were able to infect most of the major taxonomic groups of Bacillus thermophiles. The phages varied considerably in morphology and size; the phage heads were either cylindrical or polyhedral with tails varying in length between 15 and 500 nm. Most of the phages were stable at 50 degrees C for 4-5 h but at 70 degrees C the plaque-forming units decreased by between 10(2)- and 10(7)-fold in 2 h. The DNA of morphologically similar phages was examined by restriction enzyme analysis, and some differences in the DNA fragment patterns were found. Efficiency of plating data indicated that 'B. caldotenax' has a restriction and modification system. These phages may be valuable for the study of the genetics of thermophilic bacilli: transduction of 'B. caldotenax' and 'B. caldovelox' by phage JS017 has been observed. 相似文献
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Annemarieke de Jonghe Barbara C. van Munster J. Carel Goslings Peter Kloen Carolien van Rees Reinder Wolvius Romuald van Velde Marcel Levi Rob J. de Haan Sophia E. de Rooij 《CMAJ》2014,186(14):E547-E556
Background:
Disturbance of the sleep–wake cycle is a characteristic of delirium. In addition, changes in melatonin rhythm influence the circadian rhythm and are associated with delirium. We compared the effect of melatonin and placebo on the incidence and duration of delirium.Methods:
We performed this multicentre, double-blind, randomized controlled trial between November 2008 and May 2012 in 1 academic and 2 nonacademic hospitals. Patients aged 65 years or older who were scheduled for acute hip surgery were eligible for inclusion. Patients received melatonin 3 mg or placebo in the evening for 5 consecutive days, starting within 24 hours after admission. The primary outcome was incidence of delirium within 8 days of admission. We also monitored the duration of delirium.Results:
A total of 452 patients were randomly assigned to the 2 study groups. We subsequently excluded 74 patients for whom the primary end point could not be measured or who had delirium before the second day of the study. After these postrandomization exclusions, data for 378 patients were included in the main analysis. The overall mean age was 84 years, 238 (63.0%) of the patients lived at home before admission, and 210 (55.6%) had cognitive impairment. We observed no effect of melatonin on the incidence of delirium: 55/186 (29.6%) in the melatonin group v. 49/192 (25.5%) in the placebo group; difference 4.1 (95% confidence interval −0.05 to 13.1) percentage points. There were no between-group differences in mortality or in cognitive or functional outcomes at 3-month follow-up.Interpretation:
In this older population with hip fracture, treatment with melatonin did not reduce the incidence of delirium. Trial registration: Netherlands Trial Registry, NTR1576: MAPLE (Melatonin Against PLacebo in Elderly patients) study; www.trialregister.nl/trialreg/admin/rctview.asp?TC=1576Delirium in older inpatients is associated with a high risk of dementia and other complications that translate into increased mortality and health care costs.1,2 The antipsychotic haloperidol has historically been the agent of choice for treating delirium, and it has increasingly been administered as a prophylactic for delirium or to reduce symptoms such as hallucinations and aggressive behaviour.3,4 However, all antipsychotic treatments may induce serious cerebrovascular adverse effects and greater mortality, particularly among patients with dementia.5,6 These effects led the US Food and Drug Administration to issue a serious warning against their use.7 In addition, benzodiazepines are still frequently used to treat delirium, despite their being known to elicit or aggravate delirium.8,9Disturbances of the circadian sleep–wake cycle represent one of the core features of delirium,10 leading to the hypothesis that the neurotransmitter melatonin and changes in its metabolism may be involved in the pathogenesis of delirium.11,12 Objective measurements have shown that melatonin metabolism is disturbed after abdominal and other types of surgery, insomnia, sleep deprivation and stays in the intensive care unit (ICU), all of which are also known to be factors that contribute to delirium.13–16 These characteristics suggest an association between melatonin abnormalities and delirium.17–22 Although proof of a causal relation is still lacking, inpatients might nevertheless benefit from melatonin supplementation therapy through postoperative maintenance or restoration of their sleep–wake cycle.23–25 Although melatonin depletion is thought to be one of the mechanisms of delirium, few studies have investigated the effects of altering perioperative plasma concentrations of melatonin, in particular, the possible effects on postoperative delirium.The primary objective of this study was to assess the effects of melatonin on the incidence of delirium among elderly patients admitted to hospital as an emergency following hip fracture. Secondary outcomes were duration and severity of delirium, length of hospital stay, total doses of haloperidol and benzodiazepines administered to patients with delirium, mortality during the hospital stay, and functional status, cognitive function and mortality at 3-month follow-up. 相似文献7.
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Cycling of manure nutrients through turfgrass sod could affect groundwater quality. The fate of nutrients in transplanted
fertilizer- or manure-grown sod of Tifway bermudagrass (Cynodon dactylon L. Pers. X C. transvaalensis Burtt-Davey) was compared with that in composted dairy manure (CDM) applied to a sprigged treatment. Leaching loss of NO3-N and dissolved P (DP) in filtrate (<0.45 μm) of leachate was compared among sodded and sprigged treatments during periods
0–50, 60–110, and 330–380 d after planting in lysimeters. In addition, recovery of N and P in turfgrass clippings and a sand
medium was quantified. Maintenance applications of CDM or fertilizer P were top-dressed starting 60 d after planting. Leachate
was collected and sampled over three simulated rain events during each of the three sampling periods. From 0 d to 50 d after
planting, leaching loss of NO3-N from sprigged Tifway totaled 2.0 g m−2 and was 10 times greater than loss from CDM-grown or fertilizer-grown sod. In contrast, DP loss in leachate was ≤0.02 g m−2 and similar among treatments. Surface applications of CDM and fertilizer P and N increased concentration and mass of total
Kjeldahl N (TKN) and soil-test P (STP) in surface or subsurface layers of the sand medium. Yet, NO3-N mass in leachate collected over three simulated rain events ranged from 0.0 to only 1.0% of applied N from 60–110 d and
330–380 d after planting. Leaching loss of NO3-N did not differ between the sodded and sprigged treatments after two topdressings of CDM. Similarly, the DP mass recovered
in leachate was small (≤0.013 g m−1) and did not differ among treatments during the latter two sampling periods. The mass loss of DP in leachate was typically
less than the DP mass applied through irrigation or simulated rain. Importing CDM in sod reduces NO3-N leaching loss compared to sprigged turfgrass amended with CDM, but NO3-N and DP leaching losses are similar during maintenance of CDM-grown and fertilizer-grown sod from 60–110 d to 330–380 d
after transplanting.
Responsible Editor: Bernard Nicolardot. 相似文献
9.
Spatial, temporal, and species variation in prevalence of influenza A viruses in wild migratory birds 总被引:2,自引:0,他引:2
Munster VJ Baas C Lexmond P Waldenström J Wallensten A Fransson T Rimmelzwaan GF Beyer WE Schutten M Olsen B Osterhaus AD Fouchier RA 《PLoS pathogens》2007,3(5):e61
Although extensive data exist on avian influenza in wild birds in North America, limited information is available from elsewhere, including Europe. Here, molecular diagnostic tools were employed for high-throughput surveillance of migratory birds, as an alternative to classical labor-intensive methods of virus isolation in eggs. This study included 36,809 samples from 323 bird species belonging to 18 orders, of which only 25 species of three orders were positive for influenza A virus. Information on species, locations, and timing is provided for all samples tested. Seven previously unknown host species for avian influenza virus were identified: barnacle goose, bean goose, brent goose, pink-footed goose, bewick's swan, common gull, and guillemot. Dabbling ducks were more frequently infected than other ducks and Anseriformes; this distinction was probably related to bird behavior rather than population sizes. Waders did not appear to play a role in the epidemiology of avian influenza in Europe, in contrast to the Americas. The high virus prevalence in ducks in Europe in spring as compared with North America could explain the differences in virus-host ecology between these continents. Most influenza A virus subtypes were detected in ducks, but H13 and H16 subtypes were detected primarily in gulls. Viruses of subtype H6 were more promiscuous in host range than other subtypes. Temporal and spatial variation in influenza virus prevalence in wild birds was observed, with influenza A virus prevalence varying by sampling location; this is probably related to migration patterns from northeast to southwest and a higher prevalence farther north along the flyways. We discuss the ecology and epidemiology of avian influenza A virus in wild birds in relation to host ecology and compare our results with published studies. These data are useful for designing new surveillance programs and are particularly relevant due to increased interest in avian influenza in wild birds. 相似文献
10.
Jongen PJ Sindic C Sanders E Hawkins S Linssen W van Munster E Frequin S Borm G;Functional Composite Quality of Life in Avonex-treated Relapsing Multiple Sclerosis Patients Study Group 《PloS one》2011,6(10):e26568