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101.
A simple procedure for the enzymic digestion of edible tissues is described and compared with other procedures. The samples are digested overnight in an enzyme suspension containing subtilisin A at 60 degrees C and pH 9. The resulting digest contains only a few small tissue fragments. This method is suitable for routine analysis, since the manipulation of the samples is very limited.  相似文献   
102.
The purpose of this study was to describe an episode of increased mortality, whose cause was initially unknown. This retrospective cohort investigation was conducted on a dementia special care unit of a Department of Veterans Affairs facility, with more than 75% of residents clinically diagnosed with dementia of the Alzheimer type. One hundred five residents residing in the facility during February 1995 were included as subjects. A cluster of deaths occurred, triggering the investigation. Ultimately, 21 deaths (three times greater than any previous month in the past 5 years) occurred during the 1-month period. Measures included the presence of clinical influenza-like illness based on signs, serology, and autopsy results. Of the 105 residents, 45 (42.8%) met the clinical definition for influenza-like illness. Eight autopsies were performed, and the causes of death consisting of bronchopneumonia in seven and aspiration pneumonia in one were compatible with influenza. There were no differences among those who died from those who lived with regards to age, race, gender, clinical influenza-like illness, vaccination status, diagnosis of Alzheimer disease, or duration of dementia (all p > or = 0.2). However, those who died were at a higher risk of dying due to a greater number of coexisting conditions (p < 0.01). Also, overall the groups differed in Mini-Mental State Examination and Bedford Alzheimer Nursing Scale scores with those who died being more impaired (p < 0.01). Thus, the presentation of influenza-like illness can be subtle in onset, underappreciated in this population, and not recognized until excess mortality, which affects the most frail, is noted. Care providers need to be vigilant during the winter months for the presence of influenza.  相似文献   
103.
The amazing diversity of extant photosynthetic eukaryotes is largely a result of the presence of formerly free-living photosynthesizing organisms that have been sequestered by eukaryotic hosts and established as plastids in a process known as endosymbiosis. The evolutionary history of these endosymbiotic events was traditionally investigated by studying ultrastructural features and pigment characteristics but in recent years has been approached using molecular sequence data and gene trees. Two important developments, more detailed studies of members of the Cyanobacteria (from which plastids ultimately derive) and the availability of complete plastid genome sequences from a wide variety of plant and algal lineages, have allowed a more accurate reconstruction of plastid evolution.  相似文献   
104.
Most of our knowledge concerning the presence of virus specific cytotoxic T lymphocytes (CTL) in early life has been provided by studies of CTL activities against human immunodeficiency virus type 1 (HIV-1) in infected infants born to HIV-infected mothers. HIV-specific cytolytic responses were found to be similar in perinatally infected children compared with adults, with respect to the nature of effector cells, protein recognized and the ability to control viral replication. CTL responses measured immediately after PBMC isolation (ex vivo activated CTL) were observed predominantly in children with no or mild symptoms, and the presence of in vitro activated CTL was found to be associated with the absence of severe symptoms during the first year of life and survival over 5 years.  相似文献   
105.
The aim of this study was to assess the potential mechanism underlying the enhanced inflammatory processes during magnesium deficit. In this study, exacerbated response to live bacteria and platelet activating factors was shown in rats fed a magnesium-deficient diet. Peritoneal cells from these animals also showed enhanced superoxide anion production and calcium mobilising potency following in vitro stimulation. The latter effect occurred very early in the course of magnesium deficiency. These studies first showed that an abnormal calcium handling induced by extracellular magnesium depression in vivo may be at the origin of exacerbated inflammatory response.  相似文献   
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107.
Electron traps in MIS-type Schottky barriers on n-GaAs were investigated by measuring the change of the flat-band voltage, due to detrapping, as a function of time. The trap depth and the capture cross section for a particular trap were obtained from the temperature dependence of the time constant for detrapping. It was found that the detrapping process in some cases is a two-state thermionic emission and tunneling process. For other trapping levels the results indicated clearly that the mechanism was different from the thermionic emission and tunneling process.  相似文献   
108.
In the series Ti4M2Ox (M = 3d metal, x < 1) some compounds may be charged by relatively large amounts of hydrogen. It appears that the reactivity and the kinetics of hydridation depend on the high temperature treatements of the oxygen-stabilized alloys. The maximum amount of filled hydrogen increases when x decreases. Neutron diffraction experiments performed on Ti4Fe2OD2.25 enable us to localize the light atoms in several sites, an isolated one occupying the Ti-octahedra, and a cluster like arrangement which may be described using the 192 i and 96 g positions of the space group Fd3m.  相似文献   
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