3,009 research outputs found
Correlates of patient satisfaction and provider trust after breast-conserving surgery
BACKGROUND Although breast-conserving therapy (BCS) is considered the standard of care for early-stage breast cancer, up to 20% of patients are dissatisfied. The effect of treatment-related factors on patient satisfaction with their healthcare experiences is unclear. METHODS All BCS patients at the University of Michigan Medical Center who were treated between January 2002 and May 2006 were surveyed (n = 714; response rate, 79.5%). Patients were queried regarding 4 aspects of their decision for surgery: satisfaction with the decision, decision regret, decisional conflict, and trust in surgeons. Independent variables included the number of re-excisions, the occurrence of postoperative complications, and postoperative breast appearance, which was assessed by using the Breast Cancer Treatment and Outcomes scale. Multiple logistic regression was used to assess the effect of the independent variables on each outcome controlling for demographic and clinical characteristics. RESULTS Breast asymmetry after BCS was correlated significantly with patient satisfaction with their treatment experiences and patient distrust in surgeons. Women who reported pronounced asymmetry were significantly less likely to be satisfied with the decision for surgery compared with women who reported minimal asymmetry (odds ratio [OR], 0.43; 95% confidence interval [95% CI], 0.21–0.89). Women with pronounced asymmetry were less likely to be certain about their surgical decision (OR, 0.36; 95% CI, 0.21–0.60) and to believe that they were prepared to make the decision for surgery (OR, 0.25; 95% CI, 0.14–0.43). Increasing breast asymmetry was associated with higher surgeon distrust scores (2.14 vs 2.30 vs 2.35; P = .04) and with the occurrence of postoperative complications (distrust score: 2.23 vs 2.35; P = .03). Reoperation after BCS was not associated with patient satisfaction or trust in providers. CONCLUSIONS Esthetic result after BCS was associated more profoundly with aspects of satisfaction than either surgical therapy or the occurrence of postoperative complications. The current findings indicated that surgeons who care for patients with breast cancer should identify the women at an increased risk for breast asymmetry preoperatively to effectively address their expectations of treatment outcomes. Cancer 2008. © 2008 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58592/1/23351_ftp.pd
Toward Better Training in Peer Assessment: Does Calibration Help?
For peer assessments to be helpful, student reviewers need to submit reviews of good quality. This requires certain training or guidance from teaching staff, lest reviewers read each other\u27s work uncritically, and assign good scores but offer few suggestions. One approach to improving the review quality is calibration. Calibration refers to comparing students\u27 individual reviews to a standard—usually a review done by teaching staff on the same reviewed artifact. In this paper, we categorize two modes of calibration for peer assessment and discuss our experience with both of them in a pilot study with Expertiza system
Achiral dielectric metasurfaces for spectral and polarization control of valley specific light emission from monolayer MoS2
Excitons in two-dimensional transition metal dichalcogenides have a valley
degree of freedom that can be optically accessed and manipulated for quantum
information processing. Here, we integrate MoS2 with achiral silicon disk array
metasurfaces to enhance and control valley-specific absorption and emission.
Through the coupling to the metasurface Mie modes, the intensity and lifetime
of the emission of neutral excitons, trions and defect bound excitons can be
enhanced, while the spectral shape can be modified. Additionally, we
demonstrate the symmetric enhancement of the degree-of-polarization (DOP) of
neutral exciton and trions via valley-resolved PL measurements, and find that
the DOP can be as high as 24% for exciton emission and 34% for trion emission
at 100K. These results can be understood by analyzing the near-field impact of
metasurface resonators on both the chiral absorption of MoS2 emitters as well
as the enhanced emission from the Purcell effect. Combining Si-compatible
photonic design with large-scale (mm-scale) 2D materials integration, our work
makes an important step towards on-chip valleytronic applications approaching
room-temperature operation
Metropolitan Social Environments and Pre-HAART/HAART Era Changes in Mortality Rates (per 10,000 Adult Residents) among Injection Drug Users Living with AIDS
Background
Among the largest US metropolitan areas, trends in mortality rates for injection drug users (IDUs) with AIDS vary substantially. Ecosocial, risk environment and dialectical theories suggest many metropolitan areas characteristics that might drive this variation. We assess metropolitan area characteristics associated with decline in mortality rates among IDUs living with AIDS (per 10,000 adult MSA residents) after highly active antiretroviral therapy (HAART) was developed.
Methods
This is an ecological cohort study of 86 large US metropolitan areas from 1993–2006. The proportional rate of decline in mortality among IDUs diagnosed with AIDS (as a proportion of adult residents) from 1993–1995 to 2004–2006 was the outcome of interest. This rate of decline was modeled as a function of MSA-level variables suggested by ecosocial, risk environment and dialectical theories. In multiple regression analyses, we used 1993–1995 mortality rates to (partially) control for pre-HAART epidemic history and study how other independent variables affected the outcomes.
Results
In multivariable models, pre-HAART to HAART era increases in ‘hard drug’ arrest rates and higher pre-HAART income inequality were associated with lower relative declines in mortality rates. Pre-HAART per capita health expenditure and drug abuse treatment rates, and pre- to HAART-era increases in HIV counseling and testing rates, were weakly associated with greater decline in AIDS mortality.
Conclusions
Mortality among IDUs living with AIDS might be decreased by reducing metropolitan income inequality, increasing public health expenditures, and perhaps increasing drug abuse treatment and HIV testing services. Given prior evidence that drug-related arrest rates are associated with higher HIV prevalence rates among IDUs and do not seem to decrease IDU population prevalence, changes in laws and policing practices to reduce such arrests while still protecting public order should be considered
Millimeter-scale exfoliation of hBN with tunable flake thickness
As a two-dimensional (2D) dielectric material, hexagonal boron nitride (hBN)
is in high demand for applications in photonics, nonlinear optics, and
nanoelectronics. Unfortunately, the high-throughput preparation of
macroscopic-scale, high-quality hBN flakes with controlled thickness is an
ongoing challenge, limiting device fabrication and technological integration.
Here, we present a metal thin-film exfoliation method to prepare hBN flakes
with millimeter-scale dimension, near-unity yields, and tunable flake thickness
distribution from 1-7 layers, a substantial improvement over scotch tape
exfoliation. The single crystallinity and high quality of the exfoliated hBN
are demonstrated with optical microscopy, atomic force microscopy, Raman
spectroscopy, and second harmonic generation. We further explore a possible
mechanism for the effectiveness and selectivity based on thin-film residual
stress measurements, density functional theory calculations, and transmission
electron microscopy imaging of the deposited metal films. We find that the
magnitude of the residual tensile stress induced by thin film deposition plays
a key role in determining exfoliated flake thickness in a manner which closely
resembles 3D semiconductor spalling. Lastly, we demonstrate that our
exfoliated, large-area hBN flakes can be readily incorporated as encapsulating
layers for other 2D monolayers. Altogether, this method brings us one step
closer to the high throughput, mass production of hBN-based 2D photonic,
optoelectronic, and quantum devices.Comment: 21 pages, 5 figures, work completed at Stanford Universit
Toll-like receptor signaling adapter proteins govern spread of neuropathic pain and recovery following nerve injury in male mice.
BackgroundSpinal Toll-like receptors (TLRs) and signaling intermediaries have been implicated in persistent pain states. We examined the roles of two major TLR signaling pathways and selected TLRs in a mononeuropathic allodynia.MethodsL5 spinal nerve ligation (SNL) was performed in wild type (WT, C57BL/6) male and female mice and in male Tlr2-/-Tlr3-/-, Tlr4-/-, Tlr5-/-, Myd88-/-, Triflps2, Myd88/Triflps2, Tnf-/-, and Ifnar1-/- mice. We also examined L5 ligation in Tlr4-/- female mice. We examined tactile allodynia using von Frey hairs. Iba-1 (microglia) and GFAP (astrocytes) were assessed in spinal cords by immunostaining. Tactile thresholds were analyzed by 1- and 2-way ANOVA and the Bonferroni post hoc test was used.ResultsIn WT male and female mice, SNL lesions resulted in a persistent and robust ipsilateral, tactile allodynia. In males with TLR2, 3, 4, or 5 deficiencies, tactile allodynia was significantly, but incompletely, reversed (approximately 50%) as compared to WT. This effect was not seen in female Tlr4-/- mice. Increases in ipsilateral lumbar Iba-1 and GFAP were seen in mutant and WT mice. Mice deficient in MyD88, or MyD88 and TRIF, showed an approximately 50% reduction in withdrawal thresholds and reduced ipsilateral Iba-1. In contrast, TRIF and interferon receptor null mice developed a profound ipsilateral and contralateral tactile allodynia. In lumbar sections of the spinal cords, we observed a greater increase in Iba-1 immunoreactivity in the TRIF-signaling deficient mice as compared to WT, but no significant increase in GFAP. Removing MyD88 abrogated the contralateral allodynia in the TRIF signaling-deficient mice. Conversely, IFNβ, released downstream to TRIF signaling, administered intrathecally, temporarily reversed the tactile allodynia.ConclusionsThese observations suggest a critical role for the MyD88 pathway in initiating neuropathic pain, but a distinct role for the TRIF pathway and interferon in regulating neuropathic pain phenotypes in male mice
Spectroscopic scanning tunneling microscopy insights into Fe-based superconductors
In the first three years since the discovery of Fe-based high Tc
superconductors, scanning tunneling microscopy (STM) and spectroscopy have shed
light on three important questions. First, STM has demonstrated the complexity
of the pairing symmetry in Fe-based materials. Phase-sensitive quasiparticle
interference (QPI) imaging and low temperature spectroscopy have shown that the
pairing order parameter varies from nodal to nodeless s\pm within a single
family, FeTe1-xSex. Second, STM has imaged C4 -> C2 symmetry breaking in the
electronic states of both parent and superconducting materials. As a local
probe, STM is in a strong position to understand the interactions between these
broken symmetry states and superconductivity. Finally, STM has been used to
image the vortex state, giving insights into the technical problem of vortex
pinning, and the fundamental problem of the competing states introduced when
superconductivity is locally quenched by a magnetic field. Here we give a
pedagogical introduction to STM and QPI imaging, discuss the specific
challenges associated with extracting bulk properties from the study of
surfaces, and report on progress made in understanding Fe-based superconductors
using STM techniques.Comment: 36 pages, 23 figures, 229 reference
User needs elicitation via analytic hierarchy process (AHP). A case study on a Computed Tomography (CT) scanner
Background:
The rigorous elicitation of user needs is a crucial step for both medical device design and purchasing. However, user needs elicitation is often based on qualitative methods whose findings can be difficult to integrate into medical decision-making. This paper describes the application of AHP to elicit user needs for a new CT scanner for use in a public hospital.
Methods:
AHP was used to design a hierarchy of 12 needs for a new CT scanner, grouped into 4 homogenous categories, and to prepare a paper questionnaire to investigate the relative priorities of these. The questionnaire was completed by 5 senior clinicians working in a variety of clinical specialisations and departments in the same Italian public hospital.
Results:
Although safety and performance were considered the most important issues, user needs changed according to clinical scenario. For elective surgery, the five most important needs were: spatial resolution, processing software, radiation dose, patient monitoring, and contrast medium. For emergency, the top five most important needs were: patient monitoring, radiation dose, contrast medium control, speed run, spatial resolution.
Conclusions:
AHP effectively supported user need elicitation, helping to develop an analytic and intelligible framework of decision-making. User needs varied according to working scenario (elective versus emergency medicine) more than clinical specialization. This method should be considered by practitioners involved in decisions about new medical technology, whether that be during device design or before deciding whether to allocate budgets for new medical devices according to clinical functions or according to hospital department
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Refining the accuracy of validated target identification through coding variant fine-mapping in type 2 diabetes.
We aggregated coding variant data for 81,412 type 2 diabetes cases and 370,832 controls of diverse ancestry, identifying 40 coding variant association signals (P < 2.2 × 10-7); of these, 16 map outside known risk-associated loci. We make two important observations. First, only five of these signals are driven by low-frequency variants: even for these, effect sizes are modest (odds ratio ≤1.29). Second, when we used large-scale genome-wide association data to fine-map the associated variants in their regional context, accounting for the global enrichment of complex trait associations in coding sequence, compelling evidence for coding variant causality was obtained for only 16 signals. At 13 others, the associated coding variants clearly represent 'false leads' with potential to generate erroneous mechanistic inference. Coding variant associations offer a direct route to biological insight for complex diseases and identification of validated therapeutic targets; however, appropriate mechanistic inference requires careful specification of their causal contribution to disease predisposition
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Differential Stem and Progenitor Cell Trafficking by Prostaglandin E2
SUMMARY To maintain lifelong production of blood cells, hematopoietic stem cells (HSC) are tightly regulated by inherent programs and extrinsic regulatory signals received from their microenvironmental niche. Long-term repopulating HSC (LT-HSC) reside in several, perhaps overlapping, niches that produce regulatory molecules/signals necessary for homeostasis and increased output following stress/injury 1–5. Despite significant advances in specific cellular or molecular mechanisms governing HSC/niche interactions, little is understood about regulatory function within the intact mammalian hematopoietic niche. Recently, we and others described a positive regulatory role for Prostaglandin E2 (PGE2) on HSC function ex vivo 6,7. While exploring the role of endogenous PGE2 we unexpectedly observed hematopoietic egress after nonsteroidal anti-inflammatory drug (NSAID) treatment. Surprisingly, this was independent of the SDF-1/CXCR4 axis. Stem and progenitor cells were found to have differing mechanisms of egress, with HSC transit to the periphery dependent on niche attenuation and reduction in the retentive molecule osteopontin (OPN). Hematopoietic grafts mobilized with NSAIDs had superior repopulating ability and long-term engraftment. Treatment of non-human primates and healthy human volunteers confirmed NSAID-mediated egress in higher species. PGE2 receptor knockout mice demonstrated that progenitor expansion and stem/progenitor egress resulted from reduced EP4 receptor signaling. These results not only uncover unique regulatory roles for EP4 signaling in HSC retention in the niche but also define a rapidly translatable strategy to therapeutically enhance transplantation
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