2,645 research outputs found
Perspectives of staff nurses of the reasons for and the nature of patient-initiated call lights: an exploratory survey study in four USA hospitals
<p>Abstract</p> <p>Background</p> <p>Little research has been done on patient call light use and staff response time, which were found to be associated with inpatient falls and satisfaction. Nurses' perspectives may moderate or mediate the aforementioned relationships. This exploratory study intended to understand staff's perspectives about call lights, staff responsiveness, and the reasons for and the nature of call light use. It also explored differences among hospitals and identified significant predictors of the nature of call light use.</p> <p>Methods</p> <p>This cross-sectional, multihospital survey study was conducted from September 2008 to January 2009 in four hospitals located in the Midwestern region of the United States. A brief survey was used. All 2309 licensed and unlicensed nursing staff members who provide direct patient care in 27 adult care units were invited to participate. A total of 808 completed surveys were retrieved for an overall response rate of 35%. The SPSS 16.0 Window version was used. Descriptive and binary logistic regression analyses were conducted.</p> <p>Results</p> <p>The primary reasons for patient-initiated calls were for toileting assistance, pain medication, and intravenous problems. Toileting assistance was the leading reason. Each staff responded to 6 to 7 calls per hour and a call was answered within 4 minutes (estimated). 49% of staff perceived that patient-initiated calls mattered to patient safety. 77% agreed that that these calls were meaningful. 52% thought that these calls required the attention of nursing staff. 53% thought that answering calls prevented them from doing the critical aspects of their role. Staff's perceptions about the nature of calls varied across hospitals. Junior staff tended to overlook the importance of answering calls. A nurse participant tended to perceive calls as more likely requiring nursing staff's attention than a nurse aide participant.</p> <p>Conclusions</p> <p>If answering calls was a high priority among nursing tasks, staff would perceive calls as being important, requiring nursing staff's attention, and being meaningful. Therefore, answering calls should not be perceived as preventing staff from doing the critical aspects of their role. Additional efforts are necessary to reach the ideal or even a reasonable level of patient safety-first practice in current hospital environments.</p
Expanding the set of rhodococcal Baeyer–Villiger monooxygenases by high-throughput cloning, expression and substrate screening
To expand the available set of Baeyer–Villiger monooxygenases (BVMOs), we have created expression constructs for producing 22 Type I BVMOs that are present in the genome of Rhodococcus jostii RHA1. Each BVMO has been probed with a large panel of potential substrates. Except for testing their substrate acceptance, also the enantioselectivity of some selected BVMOs was studied. The results provide insight into the biocatalytic potential of this collection of BVMOs and expand the biocatalytic repertoire known for BVMOs. This study also sheds light on the catalytic capacity of this large set of BVMOs that is present in this specific actinomycete. Furthermore, a comparative sequence analysis revealed a new BVMO-typifying sequence motif. This motif represents a useful tool for effective future genome mining efforts.
A dusty pinwheel nebula around the massive star WR 104
Wolf-Rayet (WR) stars are luminous massive blue stars thought to be immediate
precursors to the supernova terminating their brief lives. The existence of
dust shells around such stars has been enigmatic since their discovery some 30
years ago; the intense radiation field from the star should be inimical to dust
survival. Although dust-creation models, including those involving interacting
stellar winds from a companion star, have been put forward, high-resolution
observations are required to understand this phenomena. Here we present
resolved images of the dust outflow around Wolf-Rayet WR 104, obtained with
novel imaging techniques, revealing detail on scales corresponding to about 40
AU at the star. Our maps show that the dust forms a spatially confined stream
following precisely a linear (or Archimedian) spiral trajectory. Images taken
at two separate epochs show a clear rotation with a period of 220 +/- 30 days.
Taken together, these findings prove that a binary star is responsible for the
creation of the circumstellar dust, while the spiral plume makes WR 104 the
prototype of a new class of circumstellar nebulae unique to interacting wind
systems.Comment: 7 pages, 2 figures, Appearing in Nature (1999 April 08
Using the MitoB method to assess levels of reactive oxygen species in ecological studies of oxidative stress
In recent years evolutionary ecologists have become increasingly interested in the effects of reactive
oxygen species (ROS) on the life-histories of animals. ROS levels have mostly been inferred indirectly
due to the limitations of estimating ROS from in vitro methods. However, measuring ROS (hydrogen
peroxide, H2O2) content in vivo is now possible using the MitoB probe. Here, we extend and refine
the MitoB method to make it suitable for ecological studies of oxidative stress using the brown trout
Salmo trutta as model. The MitoB method allows an evaluation of H2O2 levels in living organisms over
a timescale from hours to days. The method is flexible with regard to the duration of exposure and
initial concentration of the MitoB probe, and there is no transfer of the MitoB probe between fish. H2O2
levels were consistent across subsamples of the same liver but differed between muscle subsamples
and between tissues of the same animal. The MitoB method provides a convenient method for
measuring ROS levels in living animals over a significant period of time. Given its wide range of possible
applications, it opens the opportunity to study the role of ROS in mediating life history trade-offs in
ecological settings
Turing instabilities in a mathematical model for signaling networks
GTPase molecules are important regulators in cells that continuously run
through an activation/deactivation and membrane-attachment/membrane-detachment
cycle. Activated GTPase is able to localize in parts of the membranes and to
induce cell polarity. As feedback loops contribute to the GTPase cycle and as
the coupling between membrane-bound and cytoplasmic processes introduces
different diffusion coefficients a Turing mechanism is a natural candidate for
this symmetry breaking. We formulate a mathematical model that couples a
reaction-diffusion system in the inner volume to a reaction-diffusion system on
the membrane via a flux condition and an attachment/detachment law at the
membrane. We present a reduction to a simpler non-local reaction-diffusion
model and perform a stability analysis and numerical simulations for this
reduction. Our model in principle does support Turing instabilities but only if
the lateral diffusion of inactivated GTPase is much faster than the diffusion
of activated GTPase.Comment: 23 pages, 5 figures; The final publication is available at
http://www.springerlink.com http://dx.doi.org/10.1007/s00285-011-0495-
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ProCarbDB: A Database of Carbohydrate-binding Proteins
Carbohydrate-binding proteins play crucial roles across all organisms and viruses. The complexity of carbohydrate structures, together with inconsistencies in how their three-dimensional structures are reported, has led to difficulties in characterising the protein-carbohydrate interfaces. In order to better understand protein-carbohydrate interactions, we have developed an open-access database, ProCarbDB, which, unlike the Protein Data Bank (PDB), clearly distinguishes between the complete carbohydrate ligands and their monomeric units. ProCarbDB is a comprehensive database containing over 5200 three-dimensional X-ray crystal structures of protein-carbohydrate complexes. In ProCarbDB the complete carbohydrate ligands are annotated and all their interactions are displayed. Users can also select any protein residue in the proximity of the ligand to inspect its interactions with the carbohydrate ligand and with other neighbouring protein residues. Where available, additional curated information on the binding affinity of the complex and the effects of mutations on the binding have also been provided in the database. We believe that ProCarbDB will be an invaluable resource for understanding protein-carbohydrate interfaces. The ProCarbDB web server is freely available at http://www.procarbdb.science/procarb.L.C. was supported by a Collaborative Award in Science and Engineering from Ipsen Bioinnovation Ltd. to support his Research towards a PhD. D.B.A was supported by the Jack Brockhoff Foundation [JBF 4186, 2016] and the National Health and Medical Research Council of Australia [APP1072476]. P.H.M.T. was supported by The Cystic Fibrosis Trust (SRC 010 - RG92232). D.B.A and T.L.B were supported by a Newton Fund RCUK-CONFAP Grant awarded by The Medical Research Council (MRC) [MR/M026302/1]
Smc5/6: a link between DNA repair and unidirectional replication?
Of the three structural maintenance of chromosome (SMC) complexes, two directly regulate chromosome dynamics. The third, Smc5/6, functions mainly in homologous recombination and in completing DNA replication. The literature suggests that Smc5/6 coordinates DNA repair, in part through post-translational modification of uncharacterized target proteins that can dictate their subcellular localization, and that Smc5/6 also functions to establish DNA-damage-dependent cohesion. A nucleolar-specific Smc5/6 function has been proposed because Smc5/6 yeast mutants display penetrant phenotypes of ribosomal DNA (rDNA) instability. rDNA repeats are replicated unidirectionally. Here, we propose that unidirectional replication, combined with global Smc5/6 functions, can explain the apparent rDNA specificity
Studying the Effect of Adding Titanium Dioxide (TiO2) Nanoparticles on the Compressive Strength of Chemical and Heat-activated Acrylic Denture Base Resins
Problem: The commonly used acrylic resins for fabricating denture base suffer from poor mechanical properties. Aim: This study aimed to assess the effect of incorporating Titanium Dioxide (TiO2) nanoparticles (NPs) as a reinforcement agent on the compressive strength of acrylic denture base materials. Materials and methods: Thirty-two cylindrical specimens (22 mm in height and 12 mm in diameter) were prepared from PMMA resins with and without TiO2 NPs. They were allocated into two main groups according to the materials used such as cold cure and heat cure denture base resins and then subdivided into two subgroups each containing eight specimens: control (without nanoparticles) and experimental (with 2 wt.% TiO2 NPs). TiO2 NPs were synthesized via a chemical processing route and particle morphology and size distribution were assessed using SEM and AFM while XRD technique was employed to determine the crystalline structure of the NPs. Compression test was performed on the specimens using a universal Instron testing machine to compare the compressive strength. Results: Size of crystalline TiO2 NPs varied between 40-80 nm. The mean compressive strength for the cold cure acrylic resin (control group) and its nanocomposite (experimental group) were found as 15.37 MPa and 17.42 MPa while for the heat cure acrylic resin and its nanocomposite were 23.04 MPa and 24.30 MPa. A statistically significant difference was recorded in the compressive strength between the cold cure acrylic resin and its nanocomposite. However, the difference was non-significant in the case of heat cure acrylic resin. Conclusion: The compressive strength of both cold cure and heat cure acrylic resins increased after incorporation TiO2 NPs
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