156 research outputs found
The Effect of 72 Consecutive Hours in the Coronary Care Unit on the Night Sleep of 10 Patients Age 65 and Older
The prevalence of heart disease in the population over age 65 has contributed to the increasing number of aged patients hospitalized in critical care units (Gsell, 1977). Changes which occur in the process of aging and in cardiac disease should be considered when providing nursing care to these patients. A disturbance in the sleep wakefulness cycle resulting in a decrease of restorative sleep is a major change occurring at age 65 and after (Feinberg, 1967). The cardiac patient finds that it takes longer to go to sleep, and then awakens often during the night (Karacan et al., 1969).
Rome (1969) found that the environmental stimuli of the critical care unit increases the arousal of patients. Kornfield (1969) found that with an increase in arousal in critical care, the patient achieves less rest and sleep. Woods (1972) and Walker (1972) found that the rest of postcardiotomy patients in critical care was interrupted at least once every hour for the first day. Since these studies and others, which demonstrate disturbance in the sleep-wakefulness cycle of the patient in critical care, have dealt with subjects under the age of 65, they may not be applicable to the aged population.
Knowing that sleep is already disturbed in the patient over 65 and in the patient with cardiac disease, would being in a critical coronary care unit be more disturbing or would it be an insignificant factor? Studies investigating the sleep of the aged in any type of critical care unit were not found in the literature. To answer this question, it was hypothesized that 72 consecutive hours in the coronary care unit would have no effect, (p=.05) on the observed behavioral sleep patterns of 10 patients who are 65 years or older.
A non-experimental exploratory evaluation study was designed to test the hypothesis. The study sample consisted of 10 patients age 65 or older who were admitted to a seven bed CCU. Demographic data and information on home sleep was obtained by focused interviews. The performance, self-satisfaction with sleep, and mood of each subject were tested; and their sleep during their first three nights in the CCU was observed.
To test the obtained ordinal data for statistical significance three non-parametric tests were used: 1) Friedman two-way analysis of variance, 2) Spearman rank correlation coefficient and 3) Uilcoxon matched-pairs signed-ranks. Two-tailed tests were used in all instances.
In testing for differences in total sleep times for the 72 hours, the null hypothesis was rejected. On the other hand, in testing the variables: 1) age with sleep, 2) environmental stimuli and 3) nursing interruption times, the null hypothesis was retained. Even though the null hypothesis for no effect from environmental stimuli was retained, the test results were in the direction of the alternate hypothesis.
It was concluded that the sleep disturbances observed in this study were related to the normal adjustment one makes to a new environment regardless of age and/or to the state of illness and the patients concern for his health status.
The scores for performance and self-reported satisfaction with sleep were in the upper ranges and improved during the stay in CCU, demonstrating adjustment to the CCU with little detrimental effect from sleep disturbance. Mood levels, defined as anxiety and hostility, decreased during the stay in CCU with a minimal use of medication for sleep and relaxation, demonstrating a positive adjustment in CCU and little effect from sleep disturbance.
This study of patients with an age-related disturbed sleep pattern indicated that further disturbance was experienced in a new environment. Implications for nursing seem to be that nursing care should include specific efforts in presenting and reinforcing information about the environment, routines and activities of the nursing unit. Attention should also be given toward decreasing the environmental stimuli during normal times of rest and sleep and toward adjusting nursing routines to individual sleep patterns
Evaluating the effects of climate change on US agricultural systems: sensitivity to regional impact and trade expansion scenarios
Agriculture is one of the sectors that is expected to be most significantly impacted by climate change. There has been considerable interest in assessing these impacts and many recent studies investigating agricultural impacts for individual countries and regions using an array of models. However, the great majority of existing studies explore impacts on a country or region of interest without explicitly accounting for impacts on the rest of the world. This approach can bias the results of impact assessments for agriculture given the importance of global trade in this sector. Due to potential impacts on relative competitiveness, international trade, global supply, and prices, the net impacts of climate change on the agricultural sector in each region depend not only on productivity impacts within that region, but on how climate change impacts agricultural productivity throughout the world. In this study, we apply a global model of agriculture and forestry to evaluate climate change impacts on US agriculture with and without accounting for climate change impacts in the rest of the world. In addition, we examine scenarios where trade is expanded to explore the implications for regional allocation of production, trade volumes, and prices. To our knowledge, this is one of the only attempts to explicitly quantify the relative importance of accounting for global climate change when conducting regional assessments of climate change impacts. The results of our analyses reveal substantial differences in estimated impacts on the US agricultural sector when accounting for global impacts vs. US-only impacts, particularly for commodities where the United States has a smaller share of global production. In addition, we find that freer trade can play an important role in helping to buffer regional productivity shocks
Daily variation of particulate air pollution and poor cardiac autonomic control in the elderly
Particulate matter air pollution (PM) has been related to cardiovascular disease mortality in a number of recent studies. lThe pathophysiologic mechanisms for this association are under study. Low heart rate variability, a marker of poor cardiac autonomic control, is associated with higher risk of myocardial infarction and sudden cardiac death. To address the possible mechanisms for
PM-cardiovascular disease mortality, we examined the cardiac autonomic response to daily variations
in PM in 26 elderly (mean age 81) individuals for 3 consecutive weeks. Several standardized
methods were used to measure 24-hr average PM concentrations prior to the clinical test
inside (indoor PM2.5) and immediately outside (outdoor PM2.5 and PM2.5-10) of participants'
residences. Resting, supine, 6-min R wave to R wave (R-R) interval data were collected to estimate
high frequency (0.15-0.40 Hz) and low frequency (0.04-0.15 Hz) powers and standard
deviation of normal R-R intervals (SDNN) as cardiac autonomic control indices. Participant-specific
lower heart rate variability days were defined as days for which the high-frequency
indices fell below the first tertile of the individual's high-frequency distribution over the study
period. Indoor PM 25 > 15 μg/m3 was used to define high pollution days. Results show that the
odds ratio (95% confidence interval) of low heart rate variability high frequency for high (vs. not
high) pollution days was 3.08 (1.43, 6.59). The β-coefficients (standard error) from mixed models
to assess the quantitative relationship between variations in indoor PM25 and the log-transformed
high frequency, low frequency, and SDNN were: -0.029 (0.010), -0.027 (0.009), and
-0.004 (0.003), respectively. This first study of cardiac autonomic control response to daily variations
of PM2.5 indicates that increased levels of PM2.5 are associated with lower cardiac autonomic
control, suggesting a possible mechanistic link between PM and cardiovascular disease
mortality
An improved, high-quality draft genome sequence of the Germination-Arrest Factor-producing Pseudomonas fluorescens WH6
<p>Abstract</p> <p>Background</p> <p><it>Pseudomonas fluorescens </it>is a genetically and physiologically diverse species of bacteria present in many habitats and in association with plants. This species of bacteria produces a large array of secondary metabolites with potential as natural products. <it>P. fluorescens </it>isolate WH6 produces Germination-Arrest Factor (GAF), a predicted small peptide or amino acid analog with herbicidal activity that specifically inhibits germination of seeds of graminaceous species.</p> <p>Results</p> <p>We used a hybrid next-generation sequencing approach to develop a high-quality draft genome sequence for <it>P. fluorescens </it>WH6. We employed automated, manual, and experimental methods to further improve the draft genome sequence. From this assembly of 6.27 megabases, we predicted 5876 genes, of which 3115 were core to <it>P. fluorescens </it>and 1567 were unique to WH6. Comparative genomic studies of WH6 revealed high similarity in synteny and orthology of genes with <it>P. fluorescens </it>SBW25. A phylogenomic study also placed WH6 in the same lineage as SBW25. In a previous non-saturating mutagenesis screen we identified two genes necessary for GAF activity in WH6. Mapping of their flanking sequences revealed genes that encode a candidate anti-sigma factor and an aminotransferase. Finally, we discovered several candidate virulence and host-association mechanisms, one of which appears to be a complete type III secretion system.</p> <p>Conclusions</p> <p>The improved high-quality draft genome sequence of WH6 contributes towards resolving the <it>P. fluorescens </it>species, providing additional impetus for establishing two separate lineages in <it>P. fluorescens</it>. Despite the high levels of orthology and synteny to SBW25, WH6 still had a substantial number of unique genes and represents another source for the discovery of genes with implications in affecting plant growth and health. Two genes are demonstrably necessary for GAF and further characterization of their proteins is important for developing natural products as control measure against grassy weeds. Finally, WH6 is the first isolate of <it>P. fluorescens </it>reported to encode a complete T3SS. This gives us the opportunity to explore the role of what has traditionally been thought of as a virulence mechanism for non-pathogenic interactions with plants.</p
Evidence of Hot Carrier Extraction in Metal Halide Perovskite Solar Cells
The presence of hot carriers is presented in the operational properties of an
(FA,Cs)Pb(I, Br, Cl)3 solar cell at ambient temperatures and under practical
solar concentration. At 100 K, clear evidence of hot carriers is observed in
both the high energy tail of the photoluminescence spectra and from the
appearance of a non-equilibrium photocurrent at higher fluence in light J-V
measurements. At room temperature, however, the presence of hot carriers in the
emission at elevated laser fluence are shown to compete with a gradual red
shift in the PL peak energy as photo induced halide segregation begins to occur
at higher lattice temperature. The effects of thermionic emission of hot
carriers and the presence of a non-equilibrium carrier distribution are also
shown to be distinct from simple lattice heating. This results in large
unsaturated photocurrents at high powers as the Fermi distribution exceeds that
of the heterointerface controlling carrier transport and rectification
Recommended from our members
Mutualistic Co-evolution of Type III Effector Genes in Sinorhizobium fredii and Bradyrhizobium japonicum
Two diametric paradigms have been proposed to model the molecular co-evolution of microbial mutualists and their eukaryotic hosts. In one, mutualist and host exhibit an antagonistic arms race and each partner evolves rapidly to maximize their own fitness from the interaction at potential expense of the other. In the opposing model, conflicts between mutualist and host are largely resolved and the interaction is characterized by evolutionary stasis. We tested these opposing frameworks in two lineages of mutualistic rhizobia, Sinorhizobium fredii and Bradyrhizobium japonicum. To examine genes demonstrably important for host-interactions we coupled the mining of genome sequences to a comprehensive functional screen for type III effector genes, which are necessary for many Gram-negative pathogens to infect their hosts. We demonstrate that the rhizobial type III effector genes exhibit a surprisingly high degree of conservation in content and sequence that is in contrast to those of a well characterized plant pathogenic species. This type III effector gene conservation is particularly striking in the context of the relatively high genome-wide diversity of rhizobia. The evolution of rhizobial type III effectors is inconsistent with the molecular arms race paradigm. Instead, our results reveal that these loci are relatively static in rhizobial lineages and suggest that fitness conflicts between rhizobia mutualists and their host plants have been largely resolved
In Vitro and In Vivo Antagonism of a G Protein-Coupled Receptor (S1P3) with a Novel Blocking Monoclonal Antibody
Background: S1P 3 is a lipid-activated G protein-couple receptor (GPCR) that has been implicated in the pathological processes of a number of diseases, including sepsis and cancer. Currently, there are no available high-affinity, subtypeselective drug compounds that can block activation of S1P3. We have developed a monoclonal antibody (7H9) that specifically recognizes S1P3 and acts as a functional antagonist. Methodology/Principal Findings: Specific binding of 7H9 was demonstrated by immunocytochemistry using cells that over-express individual members of the S1P receptor family. We show, in vitro, that 7H9 can inhibit the activation of S1P3mediated cellular processes, including arrestin translocation, receptor internalization, adenylate cyclase inhibiton, and calcium mobilization. We also demonstrate that 7H9 blocks activation of S1P3 in vivo, 1) by preventing lethality due to systemic inflammation, and 2) by altering the progression of breast tumor xenografts. Conclusions/Significance: We have developed the first-reported monoclonal antibody that selectively recognizes a lipidactivated GPCR and blocks functional activity. In addition to serving as a lead drug compound for the treatment of sepsi
Acute effects of fine particulate air pollution on ST segment height: A longitudinal study
Background
The mechanisms for the relationship between particulate air pollution and cardiac disease are not fully understood. Air pollution-induced myocardial ischemia is one of the potentially important mechanisms.
Methods
We investigate the acute effects and the time course of fine particulate pollution (PM2.5) on myocardium ischemic injury as assessed by ST-segment height in a community-based sample of 106 healthy non-smokers. Twenty-four hour beat-to-beat electrocardiogram (ECG) data were obtained using a high resolution 12-lead Holter ECG system. After visually identifying and removing all the artifacts and arrhythmic beats, we calculated beat-to-beat ST-height from ten leads (inferior leads II, III, and aVF; anterior leads V3 and V4; septal leads V1 and V2; lateral leads I, V5, and V6,). Individual-level 24-hour real-time PM2.5 concentration was obtained by a continuous personal PM2.5 monitor. We then calculated, on a 30-minute basis, the corresponding time-of-the-day specific average exposure to PM2.5 for each participant. Distributed lag models under a linear mixed-effects models framework were used to assess the regression coefficients between 30-minute PM2.5 and ST-height measures from each lead; i.e., one lag indicates a 30-minute separation between the exposure and outcome.
Results
The mean (SD) age was 56 (7.6) years, with 41% male and 74% white. The mean (SD) PM2.5 exposure was 14 (22) μg/m3. All inferior leads (II, III, and aVF) and two out of three lateral leads (I and V6), showed a significant association between higher PM2.5 levels and higher ST-height. Most of the adverse effects occurred within two hours after PM2.5 exposure. The multivariable adjusted regression coefficients β (95% CI) of the cumulative effect due to a 10 μg/m3 increase in Lag 0-4 PM2.5 on ST-I, II, III, aVF and ST-V6 were 0.29 (0.01-0.56) μV, 0.79 (0.20-1.39) μV, 0.52 (0.01-1.05) μV, 0.65 (0.11-1.19) μV, and 0.58 (0.07-1.09) μV, respectively, with all p < 0.05.
Conclusions
Increased PM2.5 concentration is associated with immediate increase in ST-segment height in inferior and lateral leads, generally within two hours. Such an acute effect of PM2.5 may contribute to increased potential for regional myocardial ischemic injury among healthy individuals
- …