1,269 research outputs found
The Use of Bone Morphogenetic Protein in the Intervertebral Disk Space in Minimally Invasive Transforaminal Lumbar Interbody Fusion
Study Design:
Retrospective Cohort.
Objective:
The objective of this study was to characterize one surgeon’s experience over a 10-year period using rhBMP-2 in the disk space for minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).
Summary of Background Data:
MIS TLIF has been utilized as a technique for decreasing patients’ immediate postoperative pain, decreasing blood loss, and shortened hospital stays. Effectiveness and complications of rhBMP-2’s use in the disk space is limited because of its off-label status.
Methods:
Retrospective analysis of consecutive MIS TLIFs performed by senior author between 2004 and 2014. rhBMP-2 was used in the disk space in all cases. Patients were stratified based on the dose of rhBMP-2 utilized. Patients had 9 to 12 month computerized tomography scan to evaluate for bony fusion and continued follow-up for 18 months.
Results:
A total of 688 patients underwent a MIS TLIF. A medium kit of rhBMP-2 was utilized in 97 patients, and small kit was used in 591 patients. Fusion rate was 97.9% and this was not different between the 2 groups with 96/97 patients fusing in the medium kit group and 577/591 patients fusing in the small kit group. Five patients taken back to the operating room for symptomatic pseudoarthrosis, 4 reoperated for bony hyperostosis, and 10 radiographic pseudoarthroses that did not require reoperation. A statistically significant difference in the rate of foraminal hyperostosis was found when using a medium sized kit of rhBMP-2 was 4.12% (4/97 patients), compared with a small kit (0/591 patients, P=0.0004).
Conclusions:
Utilization of rhBMP-2 in an MIS TLIF leads to high fusion rate (97.9%), with an acceptable complication profile. The development of foraminal hyperostosis is a rare complication that only affected 0.6% of patients, and seems to be a dose related complication, as this complication was eliminated when a lower dose of rhBMP-2 was utilized
Phase diagram of a 1 dimensional spin-orbital model
We study a 1 dimensional spin-orbital model using both analytical and
numerical methods. Renormalization group calculations are performed in the
vicinity of a special integrable point in the phase diagram with SU(4)
symmetry. These indicate the existence of a gapless phase in an extended region
of the phase diagram, missed in previous studies. This phase is SU(4) invariant
at low energies apart from the presence of different velocities for spin and
orbital degrees of freedom. The phase transition into a gapped dimerized phase
is in a generalized Kosterlitz-Thouless universality class. The phase diagram
of this model is sketched using the density matrix renormalization group
technique.Comment: 11 pages, 5 figures, new references adde
Learning about the complexity of humanised care: findings from a longitudinal study of nurse students’ perceptions
Background, including underpinning literature and, wherever possible, the international relevance of the research The rise in elderly populations with complex long-term conditions is a global phenomenon (World Health Organisation, 2011). However evidence has emerged internationally around concerns about quality of care, particularly for older people (Katz 2011; Organisation for Economic Cooperation and Development, 2013). It has been argued that in target-driven care environments, there is the potential for care professionals to lose sight of the person receiving the care and focuses on task-completion, resulting in dehumanising care cultures (Galvin and Todres 2013). Educating nurse students to effectively as well as compassionately deliver complex care to vulnerable people represents considerable challenges. Following a number of high profile examples of poor quality care in the United Kingdom (UK) (Francis 2013), health profession education providers now follow professional body guidelines that mandate that values for compassionate practice clearly underpin curricula. Limited evidence exists however, concerning the impact of this initiative over time. This paper reports on a study that evidences the impact on students of an education programme based on a humanising care philosophy in shaping the students’ value base as they progress through their education programmes. Aim(s) and/or research question(s)/research hypothesis(es) . This paper reports on a five-phase longitudinal study exploring the impact of an undergraduate-nursing curriculum based on a humanising care philosophy on the values of individual students. Research methodology/research design, any ethical issues, and methods of data collection and analysis The study uses a qualitative longitudinal approach to understanding the beliefs and values of student nurses from the day of entry, through their education programme to completion. Focusing on two cohorts of students one year apart, data were collected by individual interview at commencement and completion and by focus groups at the end of their first placement and at the end of their first and second years. This presentation reports up to the end of the programme for the first cohort and end of second year for the second cohort. Ethics approval was gained for the entire project. At each stage of the process, students were formally invited to participate and on-going individual consent was gained. The audio-recordings were transcribed verbatim and analysed thematically. Key findings and recommendations By the end of their first placement, both groups were very similar in the expression of their values and to some extent presented a rather negative view of their experiences. However students from both groups became more articulate in expressing their values particularly in relation to their placement experience, as they moved through their programme. Four on-going and developing themes emerged from the data: personal journey, impact of the curriculum, impact of practice and values development. Overall, although each cohort followed two distinct curricula, there were few differences between the groups at each stage. Reasons for this will be discussed. Both groups felt they had become less judgmental, that the curriculum had empowered them to challenge practice and enhanced their confidence. Students also reported that their mentors (placement supervisors) role modelled authentic compassionate care in practice. Over time students’ insight into the complexity of caring developed and their understanding of the importance of practice that respected patient individuality deepened. This study has evidenced the strong link between curriculum and its impact on the evolving values of nursing students. Whilst this paper reports on a local study from one university in the UK, transferability of findings to other settings can be judged; it is argued that the insights will have resonance for nurse educators more widely as well as other health professional disciplines. References Commissioning Board Chief Nursing Officer and Department of Health Chief Nurse Advisor (2012). Compassion in Practice: Nursing, Midwifery and Care Staff. Our vision and strategy. Retrieved 22nd January 2016 from: http://www.england.nhs.uk/wp-content/uploads/2012/12/compassion-in-practice.pdf Francis Inquiry, (2013). Report of the Mid Staffordshire NHS Foundation Trust Public Inquiry: Executive summary. Crown Copyright: London. Galvin, K., Todres, L. (2013). Caring and Well-Being: A Lifeworld Approach. Routledge: Abingdon, Oxon. Katz, P.R. (2011). An International Perspective on Long Term Care: Focus on Nursing Homes. Journal of American Medical Directors Association. 12 (7): 487-492 OECD (2013) OECD Reviews of Health Care Quality: Denmark. Retrieved 7th Retrieved 22nd January 2016 from: http://www.oecd.org/els/health-systems/ReviewofHealthCareQualityDENMARK_ExecutiveSummary.pdf WHO (2011) Global Health and Ageing. Retrieved 22nd January 2016 from: http://www.who.int/ageing/publications/global_health.pdf Key words: (5) • Nurse education • Professional values • Humanising care • Curriculum • Longitudinal qualitative research 3 key points to indicate how your work contributes to knowledge development within the selected theme • Nursing students were able to clearly articulate values that underpin humanised care • This study provides evidence for the strong link between curriculum and its impact on the evolving values of nursing students • The curriculum is one factor in embedding humanised values in nursing students; further research is required
A 700 year record of Southern Hemisphere extratropical climate variability
Annually dated ice cores from West and East Antarctica provide proxies for past changes in atmospheric circulation over Antarctica and portions of the Southern Ocean, temperature in coastal West and East Antarctica, and the frequency of South Polar penetration of El Niño events. During the period AD 1700–1850, atmospheric circulation over the Antarctic and at least portions of the Southern Hemisphere underwent a mode switch departing from the out-of-phase alternation of multi-decadal long phases of EOF1 and EOF2 modes of the 850 hPa field over the Southern Hemisphere (as defined in the recent record by Thompson and Wallace, 2000; Thompson and Solomon, 2002) that characterizes the remainder of the 700 year long record. From AD 1700 to 1850, lower-tropospheric circulation was replaced by in-phase behavior of the Amundsen Sea Low component of EOF2 and the East Antarctic High component of EOF1. During the first phase of the mode switch, both West and East Antarctic temperatures declined, potentially in response to the increased extent of sea ice surrounding both regions. At the end of the mode switch, West Antarctic coastal temperatures rose and East Antarctic coastal temperatures fell, respectively, to their second highest and lowest of the record. Polar penetration of El Niño events increased during the mode switch. The onset of the AD 1700–1850 mode switch coincides with the extreme state of the Maunder Minimum in solar variability. Late 20th-century West Antarctic coastal temperatures are the highest in the record period, and East Antarctic coastal temperatures close to the lowest. Since AD 1700, extratropical regions of the Southern Hemisphere have experienced significant climate variability coincident with changes in both solar variability and greenhouse gase
Abscission Couples Cell Division to Embryonic Stem Cell Fate.
Cell fate transitions are key to development and homeostasis. It is thus essential to understand the cellular mechanisms controlling fate transitions. Cell division has been implicated in fate decisions in many stem cell types, including neuronal and epithelial progenitors. In other stem cells, such as embryonic stem (ES) cells, the role of division remains unclear. Here, we show that exit from naive pluripotency in mouse ES cells generally occurs after a division. We further show that exit timing is strongly correlated between sister cells, which remain connected by cytoplasmic bridges long after division, and that bridge abscission progressively accelerates as cells exit naive pluripotency. Finally, interfering with abscission impairs naive pluripotency exit, and artificially inducing abscission accelerates it. Altogether, our data indicate that a switch in the division machinery leading to faster abscission regulates pluripotency exit. Our study identifies abscission as a key cellular process coupling cell division to fate transitions
MeerKAT follow-up of enigmatic GLEAM 4-Jy (G4Jy) sources
We present the results from studying 140 radio sources in the GLEAM (GaLactic
and Extragalactic All-sky MWA [Murchison Widefield Array]) 4-Jy (G4Jy) Sample.
These sources were followed-up with MeerKAT to assess their radio morphology
and enable host-galaxy identification, as existing radio images of 25 to
45-arcsec resolution do not provide sufficient information. We refer to these
sources as the MeerKAT-2019 subset. The aim is to identify the host galaxy of
these sources by visually inspecting the overlays comprising radio data from
four surveys (at 150, 200, 843/1400, and 1300 MHz). Our morphological
classification and host-galaxy identification relies upon the ~7-arcsec
resolution images from MeerKAT (1300 MHz). Through the visual inspection of the
overlays, 14 radio sources in the MeerKAT-2019 subset have wide-angle tail
(WAT) morphology, 10 are head-tail, and 5 have X-, S-/Z-shaped morphology. Most
of the remaining sources have the radio morphology of typical symmetric lobes.
Of 140 sources, we find host galaxies for 98 sources, leaving 42 with no
identified host galaxy. These 42 sources still have ambiguous identification
even with higher resolution images from MeerKAT.Comment: 20 pages, 16 figures, 4 tables. Accepted in MNRA
Abscission couples cell division to embryonic stem cell fate
Cell fate transitions are key to development and homeostasis. It is thus essential to understand the cellular mechanisms controlling fate transitions. Cell division has been implicated in fate decisions in many stem cell types, including neuronal and epithelial progenitors. In other stem cells, such as embryonic stem (ES) cells, the role of division remains unclear. Here, we show that exit from naive pluripotency in mouse ES cells generally occurs after a division. We further show that exit timing is strongly correlated between sister cells, which remain connected by cytoplasmic bridges long after division, and that bridge abscission progressively accelerates as cells exit naive pluripotency. Finally, interfering with abscission impairs naive pluripotency exit, and artificially inducing abscission accelerates it. Altogether, our data indicate that a switch in the division machinery leading to faster abscission regulates pluripotency exit. Our study identifies abscission as a key cellular process coupling cell division to fate transitions
Dimerization and Incommensurate Spiral Spin Correlations in the Zigzag Spin Chain: Analogies to the Kondo Lattice
Using the density matrix renormalization group and a bosonization approach,
we study a spin-1/2 antiferromagnetic Heisenberg chain with near-neighbor
coupling and frustrating second-neighbor coupling , particularly in
the limit . This system exhibits both dimerization and
incommensurate spiral spin correlations. We argue that this system is closely
related to a doped, spin-gapped phase of the one-dimensional Kondo lattice.Comment: 18 pages, with 13 embedded encapsulated Postscript figures, uses
epsf.sty. Corrects a misstatement about the pitch angle, and contains
additional reference
Finite size spectrum, magnon interactions and magnetization of S=1 Heisenberg spin chains
We report our density matrix renormalization-group and analytical work on S=1
antiferromagnetic Heisenberg spin chains. We study the finite size behavior
within the framework of the non-linear sigma model. We study the effect of
magnon-magnon interactions on the finite size spectrum and on the magnetization
curve close to the critical magnetic field, determine the magnon scattering
length and compare it to the prediction from the non-linear model.Comment: 28 pages, 8 figures, made substantial improvement
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