bluuebunny/crossref_metadata_2025_split huggingface dataset:
Noble Gas Xenon Is a Novel Adenosine Triphosphate-sensitive Potassium Channel Opener
Authors: Bantel Carsten , Maze Mervyn , Trapp Stefan 
Published: February 2010

Background
Adenosine triphosphate-sensitive potassium (KATP) channels in brain are involved in neuroprotective mechanisms. Pharmacologic activation of these channels is seen as beneficial, but clinical exploitation by using classic K channel openers is hampered by their inability to cross the blood-brain barrier. This is different with the inhalational anesthetic xenon, which recently has been suggested to activate KATP channels; it partitions freely into the brain.

Methods
To evaluate the type and mechanism of interaction of xenon with neuronal-type KATP channels, these channels, consisting of Kir6.2 pore-forming subunits and sulfonylurea receptor-1 regulatory subunits, were expressed in HEK293 cells and whole cell, and excised patch-clamp recordings were performed.

Results
Xenon, in contrast to classic KATP channel openers, acted directly on the Kir6.2 subunit of the channel. It had no effect on the closely related, adenosine triphosphate (ATP)-regulated Kir1.1 channel and failed to activate an ATP-insensitive mutant version of Kir6.2. Furthermore, concentration-inhibition curves for ATP obtained from inside-out patches in the absence or presence of 80% xenon revealed that xenon reduced the sensitivity of the KATP channel to ATP. This was reflected in an approximately fourfold shift of the concentration causing half-maximal inhibition (IC50) from 26 +/- 4 to 96 +/- 6 microm.

Conclusions
Xenon represents a novel KATP channel opener that increases KATP currents independently of the sulfonylurea receptor-1 subunit by reducing ATP inhibition of the channel. Through this action and by its ability to readily partition across the blood-brain barrier, xenon has considerable potential in clinical settings of neuronal injury, including stroke.
Use of Serotonergic Antidepressants and Bleeding Risk in Orthopedic Patients
Authors: van Haelst Ingrid M. M. , Egberts Toine C. G. , Doodeman Hieronymus J. , Traast Han S. , Burger Bart J. , Kalkman Cor J. , van Klei Wilton A. 
Published: February 2010

Background
Selective serotonin reuptake inhibitors have been associated with an increased bleeding tendency. Information on the impact of a possible impaired hemostasis associated with the perioperative use of selective serotonin reuptake inhibitors is limited. This study aimed to determine the association between the perioperative use of selective serotonin reuptake inhibitors and the amount of blood loss during surgery and perioperative transfusion requirements.

Methods
The authors conducted a retrospective cohort study among patients who underwent elective primary total hip arthroplasty in two hospitals from the period of July 1, 2004 until July 1, 2008. The index group included all users of both serotonergic and nonserotonergic antidepressants. The reference group included a random sample (ratio 1:3) of nonusers. The primary outcome was the amount of intraoperative blood loss. The requirement for blood transfusion was a secondary outcome. The outcomes were adjusted for confounding factors (comorbidity and comedication) using regression techniques.

Results
The index group included 66 users of serotonergic and 29 users of nonserotonergic antidepressants, and the reference group included 285 patients. After adjustment for confounding factors, mean blood loss during surgery was significantly higher in the users of selective serotonin reuptake inhibitors when compared with the reference group: 95 ml (95% CI 9-181). Mean blood loss in the users of nonserotonergic antidepressants did not differ from the reference group. Users of antidepressants did not have a higher risk for transfusion.

Conclusions
Patients undergoing total hip arthroplasty who continue the use of serotonergic antidepressants show a significantly higher, but clinically unimportant, intraoperative blood loss, without an increase in perioperative transfusion requirements.
Bumetanide Alleviates Epileptogenic and Neurotoxic Effects of Sevoflurane in Neonatal Rat Brain
Authors: Edwards David A. , Shah Hina P. , Cao Wengang , Gravenstein Nikolaus , Seubert Christoph N. , Martynyuk Anatoly E. 
Published: February 2010

Background
We tested the hypothesis that in newborn rats, sevoflurane may cause seizures, neurotoxicity, and impairment in synaptic plasticity-effects that may be diminished by the Na-K-2Cl cotransporter 1 inhibitor, bumetanide.

Methods
Electroencephalography, activated caspase-3, and hippocampal long-term potentiation were measured in rats exposed to 2.1% sevoflurane for 0.5-6 h at postnatal days 4-17 (P4-P17).

Results
Arterial blood gas samples drawn at a sevoflurane concentration of 2.1% showed no evidence of either hypoxia or hypoventilation in spontaneously breathing rats. Higher doses of sevoflurane (e.g., 2.9%) caused respiratory depression. During anesthesia maintenance, the electroencephalography exhibited distinctive episodes of epileptic seizures in 40% of P4-P8 rats. Such seizure-like activity was not detected during anesthesia maintenance in P10-P17 rats. Emergence from 3 h of anesthesia with sevoflurane resulted in tonic/clonic seizures in some P10-P17 rats but not in P4-P8 rats. Bumetanide (5 micromol/kg, intraperitoneally) significantly decreased seizures in P4-P9 rats but did not affect the emergence seizures in P10-P17 rats. Anesthesia of P4 rats with sevoflurane for 6 h caused a significant increase in activated caspase-3 and impairment of long-term potentiation induction measured at 1 and 14-17 days after exposure to sevoflurane, respectively. Pretreatment of P4 rats with bumetanide nearly abolished the increase in activated caspase-3 but did not alleviate impairment of long-term potentiation.

Conclusion
These results support the possibility that excitatory output of sevoflurane-potentiated gamma-aminobutyric acid type A/glycine systems may contribute to epileptogenic and neurotoxic effects in early postnatal rats.
Liquid–solid suspension theory with reference to possible applications in geology
Authors: Di Felice Renzo 
Published: February 2010

ABSTRACTThe first part of this paper provides an overview of the state of the art of the hydrodynamics of liquid suspensions of solid particles. It is shown that knowledge of the suspension Archimedes number is sufficient to estimate the voidage–velocity parameters for suspensions of solids possessing homogenous characteristics, thereby completely defining the system from a fluid dynamic point of view. A general relation is presented which will indicate if a solid–fluid system will be in the fixed or in the suspended state depending on the relative velocity between the two phases. Modifications of the previous approach when the solid particles are not spherical have been also indicated. The basic features of the pseudo‐fluid approach are then presented. This approach is useful when the solids making up the suspension have different sizes: by the introduction of the pseudo‐fluid apparent characteristics (density and viscosity) it is possible to make basic estimations of the suspension behaviour. The second part of the paper outlines possible application of suspension theory to geological phenomena, such as the vertical transport of water–sand suspensions. Aspects of interest are the minimum pressure required for the transport of the suspension, the estimation of suspension flow rate through an overall pressure balance, the vertical transport of large ‘breccia’ blocks and the behaviour of the solid particles present in the rising conduit once the overpressure falls below the minimum value needed to sustain the flow. Finally, a warning is given on the limitations of the presented relationships (e.g. the assumption of homogeneous solid dispersion in the suspension) and on situations such as inclined conduits which require a different approach.
Exercise capacity and haemodynamics in patients with sickle cell disease with pulmonary hypertension treated with bosentan: results of the ASSET studies
Authors: Barst Robyn J. , Mubarak Kamal K. , Machado Roberto F. , Ataga Kenneth I. , Benza Raymond L. , Castro Oswaldo , Naeije Robert , Sood Namita , Swerdlow Paul S. , Hildesheim Mariana , Gladwin Mark T. ,   on behalf of the ASSET study group
Published: February 2010

SummaryDoppler‐defined pulmonary hypertension (PH) in sickle cell disease (SCD) is associated with 40% mortality at 40 months. To assess the effect of bosentan in SCD‐PH, two randomized, double‐blind, placebo‐controlled, 16‐week studies were initiated. Safety concerns are particularly relevant in SCD due to comorbid conditions. ASSET‐1 and ‐2 enrolled patients with pulmonary arterial hypertension (PAH) and pulmonary venous hypertension (PH), respectively. Haemodynamics and 6‐min walk distance (6MWD) were obtained at baseline and week 16. The studies were terminated due to slow site initiation and patient enrolment (n = 26). Bosentan appeared to be well tolerated. Although sample sizes were limited, in ASSET‐1 at baseline, 6MWD correlated with cardiac output (CO; P = 0·006) with non‐significant inverse correlations between 6MWD and pulmonary vascular resistance (PVR; P = 0·07) and between 6MWD and right atrial pressure (P = 0·08). In ASSET‐2 at baseline, there was a non‐significant correlation between 6MWD and CO (P = 0·06). Due to limited sample sizes, efficacy endpoints were not analysed. However, in both studies, non‐significant increases in CO were observed with bosentan compared to placebo. Similarly, non‐significant decreases in PVR were observed with bosentan. Limited data in SCD‐PH suggest that a low 6MWD predicts a low CO. Standard‐dose bosentan appears to be well tolerated. Further investigation is warranted. Clinicaltrials.gov registration numbers NCT00310830, NCT00313196, NCT00360087.
What drives retrogressive succession? Plant strategies to tolerate infertile and poorly drained soils
Authors: Gaxiola Aurora , McNeill Stephen M. , Coomes David A. 
Published: February 2010

Summary 1. During retrogressive succession, vegetation shifts from taller forests with higher species richness to shorter woody communities of lower diversity. Studies of soil chronosequences have emphasized the role of phosphorus (P) depletion in driving these changes in community structure and composition, but neglected the possible role of poor drainage which is often associated with the oldest sites. 2. We used a fully factorial pot experiment to investigate the effects of soil water conditions and P availability on seedling relative growth rate and survival of 11 woody species associated with a 290 000‐year chronosequence in southern New Zealand. Species were chosen to represent three stages of the chronosequence: young P‐rich soils; intermediate‐age P‐depleted soils; and old P‐depleted, waterlogged soils. Plants were grown in soils taken from youngest and oldest sites of the chronosequence; half the pots were freely drained whilst the other half were waterlogged. 3. Species associated with intermediate‐age soils were typical ‘stress‐tolerators’; those of the youngest and oldest sites were faster growing and more responsive to nutrient availability. Only the latter showed tolerance of waterlogging. Specific root length and adventitious‐root production were important determinants of species’ responses to soil water conditions and nutrient supply. 4. Our study highlights that soil waterlogging and P depletion interact to influence relative growth rate and survival; P depletion is not the sole driver of ecosystem changes in the retrogressive stages of the soil chronosequence. We also show that some species associated with our retrogression did not necessarily conform to conventional views on ‘stress‐tolerance’, but were well adapted to poor drainage.
Self‐shading affects allometric scaling in trees
Authors: Duursma Remko A. , Mäkelä Annikki , Reid Douglas E.B. , Jokela Eric J. , Porté Annabel J. , Roberts Scott D. 
Published: February 2010

Summary1. Westet al.[Science,284(1999) 1677] derived an optimal body‐size scaling exponent under the assumption that resources are evenly distributed among exchange surfaces, leading to the well‐known ¾ scaling rule. In trees, this implies a volume‐filling branching network (a fractal dimension of 3 for foliage). However, there is evidence that the fractal dimension is less than 3 in trees.2. Here, we include self‐shading in the derivation of optimal fractal dimensions. With self‐shading, resources are not evenly distributed among leaves because light enters the crown at the surface and is gradually attenuated within the crown. We find that the optimal fractal dimension can take values between 2 and 3, depending on light interception properties and crown size.3. For a large data set on foliage and woody biomass in gymnosperm trees, we confirm that the fractal dimension of foliage is less than 3, and that it shows a weak dependence on crown size. However, foliage biomass scaled with crown woody biomass with an exponent of 0·78, very close to the theoretical expectation of ¾ scaling. This can be explained by a deviation from the theoretical prediction in the scaling of crown woody biomass and crown length.4. Overall, these results confirm a deviation from volume filling in gymnosperm trees, and we provide an explanation for this deviation in terms of optimal metabolic scaling. Because ¾ scaling of foliage biomass is still approximately valid, this implies that metabolic scaling exponents may not be as tightly linked to the fractal dimension of foliage as previously assumed.
Review of triage reform: the case for national consensus on a single triage scale for clients with a mental illness in Australian emergency departments
Authors: Broadbent Marc , Creaton Anne , Moxham Lorna , Dwyer Trudy 
Published: February 2010

Aims and objectives.  The aim of this paper is to examine the use of mental health triage scales in Australian emergency departments (EDs) and to explore the use of the Australasian Triage Scale (ATS) with existing mental health triage scales.Background.  Since the introduction of mainstreaming and deinstitutionalisation in Australian mental health care, the number of clients presenting to Australian EDs has been increasing. It has become apparent that the lack of mental health descriptors in existing triage scales diminishes the ability of ED triage staff to accurately assess clients with a mental illness. In response to this, specialised mental health triage scales have been developed and introduced into practice. Concurrently, mental health descriptors have been incorporated into the ATS used across Australian EDs.Design.  A review of English language literature was conducted.Method.  The data bases Proquest, Synergy and CINAHL were searched using the key words ‘emergency department’, ‘triage’, ‘mental health’ and again using the term ‘emergency mental health triage’.Results.  There is a paucity of literature surrounding the use of mental health triage scales in Australian EDs; 18 articles were found to be directly relevant to the subject matter.Conclusion.  Currently clients with a mental illness presenting to the ED may be triaged against one of four mental health triage scales. Research has shown that the mental health descriptors in the ATS are not as reliable as a specialised mental health triage scale.Relevance to clinical practice.  This has implications for clinical practice on two levels. First, it affects the initial triage assessment in the ED and the ability for mental health clinicians to respond in a timely manner and this will have an impact on clinical outcomes. Second, the use of the mental health triage criteria in the ATS may misrepresent ED workloads and affect data pertaining to ED performance.
Addressing health literacy: the experiences of undergraduate nursing students
Authors: Scheckel Martha , Emery Nicole , Nosek Catherine 
Published: February 2010

Aims and objectives.  To describe undergraduate nursing students’ experiences of learning and providing patient education.Background.  To teach nursing students principles and practices of patient education, nurse educators design instructional strategies using educational and clinical practice guidelines, research and theories. This means teachers’ approaches to teaching patient education are derived from evidence and support the evidence‐based teaching movement. Despite their efforts, research shows that students lack knowledge and skills needed for proficiency in providing patient education. However, this research does not explicate students’ experiences of learning and providing patient education, which can inform teachers of ways to structure approaches to teaching students this nursing practice.Design.  The philosophical background for this study was interpretive phenomenology.Methods.  Eight undergraduate nursing students in their final semester of a baccalaureate nursing programme were interviewed using face‐to‐face, unstructured interviews. Data were collected using unstructured interviews and analysed using hermeneutics.Results.  Common meanings from the analysis of data shows that a primary practice of students’ learning and providing patient education is addressing health literacy. Three sub‐themes: (1) respecting languages: learning persistence (2) helping patients understand: learning to teach and (3) promoting engagement: learning sensitivity, exemplify how students are addressing health literacy.Conclusions.  Contrary to literature on students’ lack of proficiency in providing patient education, the findings of this study reveal extraordinary competencies students already have in addressing health literacy. The results of this study show the paramount need for teachers to design instructional strategies that deepen students’ extant knowledge and skills in health literacy prior to graduation from nursing programmes.Relevance to clinical practice.  Using the findings of this study, teachers will gain novel approaches to teaching patient education that specifically target instructing students in the practices of health literacy. These practices can ameliorate and mitigate problems many students encounter when addressing health literacy.
Well‐being in patients and relatives after open‐heart surgery from the perspective of health care professionals
Authors: Karlsson Ann‐Kristin , Mattsson Bengt , Johansson Mats , Lidell Evy 
Published: February 2010

Aim.  The aim of this study was to explore how health care professionals perceive the well‐being of patients and relatives following open‐heart surgery.Background.  Open‐heart surgery is an extraordinary life event associated with hope and fear among both patients and relatives, thus they require attention from health care professionals. Patients’ short stay in hospital after surgery and the workload of health care professionals increase the risk that reduced well‐being will be overlooked. Health care professionals need to become familiar with the signs of reduced well‐being.Design.  The study has an observational design and was performed using a qualitative method.Method.  Health care professionals working with patients who have undergone open‐heart surgery participated in focus group discussions. The data were analysed by means of content analysis.Results.  Two categories emerged: signs of vulnerability and signs of insecurity. The latent meaning of the study was interpreted as awareness of an exposed position.Conclusion.  The health care professionals were aware of patients’ and relatives’ exposed position following open‐heart surgery. Reduced well‐being was communicated by bodily and emotional signs, which were captured using direct communication or intuition.Relevance to clinical practice.  Developing the ability to recognise signs of reduced well‐being is important for minimising the negative influences associated with open‐heart surgery for patients and relatives. Increased awareness that both anger and avoidance can mask depression is important. Patients and their relatives, particularly younger ones, should be observed to ensure early detection of a life crisis provoked by the heart disease. Furthermore, staff should invite patients and their partners to talk about sexuality. Changes aimed at increasing patients’ and relatives’ well‐being would be facilitated by interdisciplinary teamwork, ‘reflection groups’ for a greater exchange of knowledge and the implementation of a patient/family perspective. The latter would lead to greater interest in the relatives’ situation and position in cardiac care.
Clinical teachers’ approaches to nursing
Authors: Forbes Helen 
Published: February 2010

Aims and objectives.  The aim of the study was to investigate clinical teachers’ experiences of nursing and clinical teaching of undergraduate university students. This article reports on clinical teachers’ approaches to nursing, which is one part of that study.Background.  A lack of knowledge and understanding exists about how clinical teachers approach nursing. There is a likely relationship between approaches to nursing and what is focused on when teaching undergraduate nursing students in the clinical setting. It is therefore important to understand the variation in how clinical teachers approach nursing.Design.  Phenomenography.Method.  Semi‐structured interviews of 20 practicing nurses currently employed as clinical teachers from a range of Australian universities were conducted. Data were analysed using a phenomenographic approach.Results.  Key aspects of variation in clinical teacher approaches to nursing were identified. The results suggest that clinical teachers approach nursing in one of two ways, either a patient‐focused approach or a nurse‐focused approach. The research findings extend knowledge that will assist with preparation and support of clinical teachers.Conclusion.  Knowledge of the different approaches to nursing provides a structure for helping clinical teachers increase their awareness of both their approach to nursing and the implications for their nursing and teaching.Relevance to clinical practice.  Awareness of complex approaches to nursing may be required for multidisciplinary care.