2,130 research outputs found
High turnover in electro-oxidation of alcohols and ethers with a glassy carbon-supported phenanthroimidazole mediator.
Glassy carbon electrodes covalently modified with a phenanthroimidazole mediator promote electrochemical alcohol and ether oxidation: three orders of magnitude increase in TON, to ∼15 000 in each case, was observed compared with homogeneous mediated reactions. We propose the deactivation pathways in homogeneous solution are prevented by the immobilization: modified electrode reversibility is increased for a one-electron oxidation reaction. The modified electrodes were used to catalytically oxidize p-anisyl alcohol and 1-((benzyloxy)methyl)-4-methoxybenzene, selectively, to the corresponding benzaldehyde and benzyl ester, respectively
GPs' recognition of death in the foreseeable future and diagnosis of a fatal condition: a national survey
Background: Nowadays, palliative care is considered as a care continuum that may start early in the course of the disease. In order to address the evolving needs of patients for palliative care in time, GPs should be aware in good time of the diagnosis and of the imminence of death. The aim of the study was to gain insight into how long before a non-sudden death the diagnosis of the disease ultimately leading to death is made and on what kind of information the diagnosis is based. In addition, we aimed to explore when, and based on what kind of information, GPs become aware that death of a patient will be in the foreseeable future.
Methods: A written questionnaire focusing on the GPs' experiences with their last patient who died non-suddenly was sent to a random representative sample of 850 GPs in the Netherlands.
Results: The data were analysed of the 297 GPs who responded. 76% of the reported cases were cancer patients and 24% were patients with another non-sudden cause of death. The diagnosis was made only in the last week of life for 15% of the non-cancer patients and 1% of the patients with cancer. GPs were most likely to have been informed of the diagnosis by the medical specialist, although particularly in the case of non-cancer patients GPs also relied on their own assessment of the diagnosis or on other information sources.
The GP remained unaware that the patient would die in the foreseeable future until the last week of life in 26% of the non-cancer group, while this was the case for only 6% of the cancer patients. GP's awareness was most likely to be based on the GP's own observations of problems and/or symptoms.
Conclusions: The GP often only becomes aware of a fatal diagnosis and of death in the foreseeable future at a late stage in the disease trajectory, particularly in the case of non-cancer patients. It can be assumed that if the diagnosis and the nearing death are only recognised at a late stage, palliative care is either started at a very late stage or not at all
Complexity of diatom response to Lateglacial and Holocene climate and environmental change in ancient, deep and oligotrophic Lake Ohrid (Macedonia and Albania)
© Author(s) 2016. Lake Ohrid (Macedonia and Albania) is a rare example of a deep, ancient Mediterranean lake and is a key site for palaeoclimate research in the northeastern Mediterranean region. This study conducts the analysis of diatoms as a proxy for Lateglacial and Holocene climate and environmental change in Lake Ohrid at a higher resolution than in previous studies. While Lake Ohrid has the potential to be sensitive to water temperature change, the data demonstrate a highly complex diatom response, probably comprising a direct response to temperature-induced lake productivity in some phases and an indirect response to temperaturerelated lake stratification or mixing and epilimnetic nutrient availability in others. The data also demonstrate the possible influence of physical limnological (e.g. the influence of wind stress on stratification or mixing) and chemical processes (e.g. the influence of catchment dynamics on nutrient input) in mediating the complex response of diatoms. During the Lateglacial (ca. 12 300-11 800 cal yr BP), the low-diversity dominance of hypolimnetic Cyclotella fottii indicates low lake productivity, linked to low water temperature. Although the subsequent slight increase in small, epilimnetic C. minuscula during the earliest Holocene (ca. 11 800-10 600 cal yr BP) suggests climate warming and enhanced stratification, diatom concentration remains as low as during the Lateglacial, suggesting that water temperature increase was muted across this major transition. The early Holocene (ca. 10 600-8200 cal yr BP) is characterised by a sustained increase in epilimnetic taxa, with mesotrophic C. ocellata indicating high water-temperature-induced productivity between ca. 10 600-10 200 cal yr BP and between ca. 9500-8200 cal yr BP and with C. minuscula in response to low nutrient availability in the epilimnion between ca. 10 200-9500 cal yr BP. During the middle Holocene (ca. 8200-2600 cal yr BP), when sedimentological and geochemical proxies provide evidence for maximum Holocene water temperature, anomalously low C. ocellata abundance is probably a response to epilimnetic nutrient limitation, almost mimicking the Lateglacial flora apart from the occurrence of mesotrophic Stephanodiscus transylvanicus in the hypolimnion. During the late Holocene (ca. 2600 cal yr BP-present), high abundance and fluctuating composition of epilimnetic taxa are probably a response more to enhanced anthropogenic nutrient input, particularly nitrogen enrichment, than to climate. Overall, the data indicate that previous assumptions concerning the linearity of diatom response in this deep, ancient lake are invalid, and multi-proxy analysis is essential to improve understanding of palaeolimnological dynamics in future research on the long, Quaternary sequence
Pollen-based temperature and precipitation changes in the Ohrid Basin (western Balkans) between 160 and 70 ka
Our study aims to reconstruct climate changes that occurred at Lake Ohrid
(south-western Balkan Peninsula), the oldest extant lake in Europe, between
160 and 70 ka (covering part of marine isotope stage 6, MIS 6; all of MIS 5;
and the beginning of MIS 4). A multi-method approach, including the “Modern
Analog Technique” and the “Weighted Averaging Partial Least-Squares Regression”, is
applied to the high-resolution pollen sequence of the DEEP site, collected
from the central part of Lake Ohrid, to provide quantitative estimates of
climate and bioclimate parameters. This allows us to document climatic change
during the key periods of MIS 6 and MIS 5 in southern Europe, a region where
accurate climate reconstructions are still lacking for this time interval.
Our results for the penultimate glacial show cold and dry conditions, while the onset of
the “last interglacial” is characterized by wet and warm conditions, with temperatures
higher than today (by ca. 2 ∘C). The Eemian also shows the well-known climatic
tri-partition in the Balkans, with an initial pre-temperate phase of abrupt warming
(128–121 ka), a central temperate phase with decreasing temperatures associated with
wet conditions (121–118 ka), followed by a post-temperate phase of progressive change
towards cold and dry conditions (118–112 ka).
After the Eemian, an alternation of four warm/wet periods with cold/dry
ones, likely related to the succession of Greenland stadials and cold events
known from the North Atlantic, occurred. The observed pattern is also
consistent with hydrological and isotopic data from the central
Mediterranean.
The Lake Ohrid climate reconstruction shows greater similarity with climate
patterns inferred from northern European pollen records than with southern
European ones, which is probably due to its intermediate position and the
mountainous setting. However, this hypothesis needs further testing as very
few climate reconstructions are available for southern Europe for this key
time period.</p
A nationwide survey of patient problem occurrence across different nursing healthcare sectors
Aim: The aim of this study was to determine the patient problems that nurses encounter in different clinical settings and the extent to which they report being able to influence those patient problems. Design: Exploratory online survey research. Method Data were collected through an online questionnaire. We prepared a 2 × 2 matrix to compare the rate of occurrence against the average level of reported influence. Descriptive statistics were used for the data analysis. Results: A total of 440 nurses working in different settings completed the questionnaire. Nurses report having the most influence on patient problems related to self-care, mobility and functions of the skin. Nurses experience less influence on problems with voice/speech and the tasks required for participation in work/employment
Genome-wide analysis points to roles for extracellular matrix remodeling, the visual cycle, and neuronal development in myopia
Myopia, or nearsightedness, is the most common eye disorder, resulting
primarily from excess elongation of the eye. The etiology of myopia, although
known to be complex, is poorly understood. Here we report the largest ever
genome-wide association study (43,360 participants) on myopia in Europeans. We
performed a survival analysis on age of myopia onset and identified 19
significant associations (p < 5e-8), two of which are replications of earlier
associations with refractive error. These 19 associations in total explain 2.7%
of the variance in myopia age of onset, and point towards a number of different
mechanisms behind the development of myopia. One association is in the gene
PRSS56, which has previously been linked to abnormally small eyes; one is in a
gene that forms part of the extracellular matrix (LAMA2); two are in or near
genes involved in the regeneration of 11-cis-retinal (RGR and RDH5); two are
near genes known to be involved in the growth and guidance of retinal ganglion
cells (ZIC2, SFRP1); and five are in or near genes involved in neuronal
signaling or development. These novel findings point towards multiple genetic
factors involved in the development of myopia and suggest that complex
interactions between extracellular matrix remodeling, neuronal development, and
visual signals from the retina may underlie the development of myopia in
humans
Modeling of water balance response to an extreme future scenario in the Ötztal catchment, Austria
The aim of the study was to investigate the impact of climate change on the
water balance of the Ötztaler Ache catchment in Tyrol, Austria. For this
purpose the conceptual hydrological model HBV-D REG was applied. First, the
model was calibrated and validated using current observed climate and
discharge data. Second, the calibrated model was applied with reanalysis
data. Third, downscaled climate scenarios from 2010 to 2099 served as input
data to the HBV-D REG. Thereby two extreme land cover scenarios were
considered: for water balance modeling a constant glacier coverage from today
and additionally for runoff simulations a complete loss of glaciered area.
The downscaled climate data were generated with the expanded downscaling
method. Scenario simulations indicated an increase in annual areal
temperature by 3.4 °C and a slight decrease in annual areal
precipitation by 89 mm in the next one hundred years. According to the hydrological
modeling, these climate changes caused an increase in evapotranspiration and
a decrease in snow coverage. Furthermore model simulations showed an increase
in winter and spring runoff, whereas summer runoff was highly sensitive to
glacier coverage and decreased with complete loss of glacier coverage
- …