1,167 research outputs found
Highly accurate calculations of the rotationally excited bound states in three-body systems
An effective optimization strategy has been developed to construct highly
accurate bound state wave functions in various three-body systems. Our
procedure appears to be very effective for computations of weakly bound states
and various excited states, including rotationally excited states, i.e. states
with . The efficiency of our procedure is illustrated by computations
of the excited states in the and muonic
molecular ions, states in the non-symmetric and
ions and and states in He atom(s)
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Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial
Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events
Effects of alteplase for acute stroke on the distribution of functional outcomes: a pooled analysis of 9 trials
BackgroundâThrombolytic therapy with intravenous alteplase within 4.5 hours of ischemic stroke onset increases the overall likelihood of an excellent outcome (no, or nondisabling, symptoms). Any improvement in functional outcome distribution has value, and herein we provide an assessment of the effect of alteplase on the distribution of the functional level by treatment delay, age, and stroke severity.
MethodsâPrespecified pooled analysis of 6756 patients from 9 randomized trials comparing alteplase versus placebo/open control. Ordinal logistic regression models assessed treatment differences after adjustment for treatment delay, age, stroke severity, and relevant interaction term(s).
ResultsâTreatment with alteplase was beneficial for a delay in treatment extending to 4.5 hours after stroke onset, with a greater benefit with earlier treatment. Neither age nor stroke severity significantly influenced the slope of the relationship between benefit and time to treatment initiation. For the observed case mix of patients treated within 4.5 hours of stroke onset (mean 3 hours and 20 minutes), the net absolute benefit from alteplase (ie, the difference between those who would do better if given alteplase and those who would do worse) was 55 patients per 1000 treated (95% confidence interval, 13â91; P=0.004).
ConclusionsâTreatment with intravenous alteplase initiated within 4.5 hours of stroke onset increases the chance of achieving an improved level of function for all patients across the age spectrum, including the over 80s and across all severities of stroke studied (top versus bottom fifth means: 22 versus 4); the earlier that treatment is initiated, the greater the benefit
Incidental findings found in "healthy" volunteers during imaging performed for research: current legal and ethical implications
Incidental findings found in âhealthyâ volunteers during research imaging are common and have important implications for study design and performance, particularly in the areas of informed consent, subjects' rights, clinical image analysis and disclosure. In this study, we aimed to determine current practice and regulations concerning information that should be given to research subjects when obtaining consent, reporting of research images, who should be informed about any incidental findings and the method of disclosure. We reviewed all UK, European and international humanitarian, legal and ethical agencies' guidance. We found that the guidance on what constitutes incidental pathology, how to recognise it and what to do about it is inconsistent between agencies, difficult to find and less complete in the UK than elsewhere. Where given, guidance states that volunteers should be informed during the consent process about how research images will be managed, whether a mechanism exists for identifying incidental findings, arrangements for their disclosure, the potential benefit or harm and therapeutic options. The effects of incidentally discovered pathology on the individual can be complex and far-reaching. Radiologist involvement in analysis of research images varies widely; many incidental findings might therefore go unrecognised. In conclusion, guidance on the management of research imaging is inconsistent, limited and does not address the interests of volunteers. Improved standards to guide management of research images and incidental findings are urgently required
On the nuclear reaction in the three-electron Li atom
The nuclear reaction of the three-electron Li atom with
thermal/slow neutrons is considered. An effective method has been developed for
determining the probabilities of formation of various atoms and ions in
different bound states. We discuss a number of fundamental questions directly
related to numerical computations of the final state atomic probabilities. A
few appropriate variational expansions for atomic wave functions of the
incident lithium atom and final helium atom and/or tritium negatively charged
ion are discussed. It appears that the final He atom arising during the
nuclear Li; He-reaction in the three-electron Li atom can
also be created in its triplet states. The formation of the quasi-stable
three-electron during the nuclear reaction at the Li atom is
briefly discussed. Bremsstrahlung emitted by atomic electrons accelerated by
the rapidly moving nuclear fragments from this reaction is analyzed. The
frequency spectrum of the emitted radiation is investigated.Comment: arXiv admin note: substantial text overlap with arXiv:1107.381
Management of incidental findings during imaging research in "healthy" volunteers: current UK practice
OBJECTIVES: Incidental findings (IF) are becoming increasingly common due to the proliferation of imaging research. IFs can be life-changing for âhealthyâ volunteers. This study examined variation in IF management in UK research studies of healthy volunteers, including comparison with ethical and legal guidelines, thus providing baseline data and informing future practice. METHODS: Questionnaire of participant background [medical/non-medical; radiologist/non-radiologist; years as principal investigator (PI)], type of research (involving children or not), institutional policy, volunteer information, radiologist involvement in reporting scans and IF disclosure mechanisms. Investigator's current and perceived âidealâ practice was examined. Participants were PIs performing imaging research of healthy volunteers approved by UK ethics committees (2006â2009). RESULTS: 63/146 (43%) surveys completed. 54/61 (88.5%) had site-specific guidelines. Information commonly provided to volunteers should IF be found: personal data (51/62; 82%), contingency plans (54/62; 87%) and disclosure to general practitioner (GP)/treating physician (47/62; 76%). PIs used different strategies for image review. Commonest: radiologist reports research scans only when researcher suspicious of IF [15/57 (26%) compared with 5/28 (16%) in ideal practice]. Commonest ideal reporting strategy: routine reporting by specialist radiologists [9/28 (29%) compared with 8/57 (14%) in current practice]. 49/56 (87.5%) have a standardised disclosure contingency plan, usually involving GP. PIs most commonly disclosed IFs to volunteers when judged relevant (27/58; 47%), most commonly face to face (22/54; 41%), by volunteer's GP (26/60; 43%). Background of PI influenced consent, reporting and disclosure practice. CONCLUSION: There is wide variation in handling IFs in UK imaging research. Much of the current practice contravenes the vague existing legal and ethical guidelines, and is unlikely to be in the best interests of volunteers or researchers
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