85 research outputs found
Predictors and Characteristics of Rib Fracture Following SBRT for Lung Tumors
Background
Stereotactic body radiation therapy (SBRT) is an increasingly utilized therapy for primary and metastatic lung tumors. Despite promising tumor control, SBRT is associated with increased risk of rib osteoradionecrosis leading to rib fracture. We aimed to 1) determine clinical, demographic, and procedural risk factors of osteonecrosis and 2) radiographically characterize rib osteonecrotic fractures.
Methods
We retrospectively identified 106 patients who underwent SBRT between 2015 and 2018 for a primary or metastatic lung neoplasm with a minimum of 12 months of follow up. Patients with incomplete records, prior ipsilateral thoracic radiotherapy, or relevant trauma were excluded. Computed tomography (CT) scans were reviewed to identify and characterize rib fractures. Multivariate logistic regression modeling was used to elucidate clinical, demographic, and procedural risk factors (e.g., age, sex, race, medical comorbidities, dosage, and tumor location).
Results
A total of 106 patients with 111 treated tumors satisfied the inclusion criteria, 35 (32%) of whom developed at least one fractured rib (60 total ribs). The maximum number of affected ribs per subject was five. Multivariate regression identified posterolateral location as an independent risk factor for rib fracture. Radiographically, fractures in 77% of affected subjects showed discontinuity between healing edges.
Discussion
Post-SBRT fractures demonstrated distinct discontinuity, a possible signal of osteoradionecrosis. Tumor location along the posterolateral chest wall was the only independent predictor of rib fracture. Given its increasing frequency of use, understanding the risk profile of SBRT is vital to maintain patient safety and appropriately inform patient expectations
Experimental delayed-choice entanglement swapping
Motivated by the question, which kind of physical interactions and processes
are needed for the production of quantum entanglement, Peres has put forward
the radical idea of delayed-choice entanglement swapping. There, entanglement
can be "produced a posteriori, after the entangled particles have been measured
and may no longer exist". In this work we report the first realization of
Peres' gedanken experiment. Using four photons, we can actively delay the
choice of measurement-implemented via a high-speed tunable bipartite state
analyzer and a quantum random number generator-on two of the photons into the
time-like future of the registration of the other two photons. This effectively
projects the two already registered photons onto one definite of two mutually
exclusive quantum states in which either the photons are entangled (quantum
correlations) or separable (classical correlations). This can also be viewed as
"quantum steering into the past"
Tripartite interactions between two phase qubits and a resonant cavity
The creation and manipulation of multipartite entangled states is important
for advancements in quantum computation and communication, and for testing our
fundamental understanding of quantum mechanics and precision measurements.
Multipartite entanglement has been achieved by use of various forms of quantum
bits (qubits), such as trapped ions, photons, and atoms passing through
microwave cavities. Quantum systems based on superconducting circuits have been
used to control pair-wise interactions of qubits, either directly, through a
quantum bus, or via controllable coupling. Here, we describe the first
demonstration of coherent interactions of three directly coupled
superconducting quantum systems, two phase qubits and a resonant cavity. We
introduce a simple Bloch-sphere-like representation to help one visualize the
unitary evolution of this tripartite system as it shares a single microwave
photon. With careful control and timing of the initial conditions, this leads
to a protocol for creating a rich variety of entangled states. Experimentally,
we provide evidence for the deterministic evolution from a simple product
state, through a tripartite W-state, into a bipartite Bell-state. These
experiments are another step towards deterministically generating multipartite
entanglement in superconducting systems with more than two qubits
Von Bezold assimilation effect reverses in stereoscopic conditions
Lightness contrast and lightness assimilation are opposite phenomena: in contrast,
grey targets appear darker when bordering bright surfaces (inducers) rather than dark ones; in
assimilation, the opposite occurs. The question is: which visual process favours the occurrence
of one phenomenon over the other? Researchers provided three answers to this question. The
first asserts that both phenomena are caused by peripheral processes; the second attributes their
occurrence to central processes; and the third claims that contrast involves central processes,
whilst assimilation involves peripheral ones. To test these hypotheses, an experiment on an IT
system equipped with goggles for stereo vision was run. Observers were asked to evaluate the
lightness of a grey target, and two variables were systematically manipulated: (i) the apparent
distance of the inducers; and (ii) brightness of the inducers. The retinal stimulation was kept
constant throughout, so that the peripheral processes remained the same. The results show that
the lightness of the target depends on both variables. As the retinal stimulation was kept constant, we
conclude that central mechanisms are involved in both lightness contrast and lightness assimilation
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Brief Online Self-help Exercises for Postnatal Women to Improve Mood: A Pilot Study
OBJECTIVES: Giving birth and adjusting to a new baby can be difficult and stressful for new mothers. Negative mood may occur during this time and can affect women, their parenting and the infant's development. This pilot study evaluated a brief online self-help intervention designed to promote positive mood in mothers of babies and toddlers.
METHODS: Women in the UK who had given birth within the previous 18 months were randomly allocated to the online self-help intervention (n = 40) or active comparison group exercise (n = 40) which was matched for time and structure. Mood was measured before and after the intervention. Acceptability was examined at the end of the trial.
RESULTS: The self-help intervention was acceptable to the majority of women and significantly increased positive mood compared to the comparison condition. This effect persisted after controlling for self-esteem, anxiety and depression. These results suggest that a simple self-help intervention focused on changing beliefs about oneself as a mother can have an immediate impact on women's mood.
CONCLUSIONS FOR PRACTICE: Further research is need to see whether these improvements continue long-term and what processes underlie these improvements
Measuring dementia carers' unmet need for services - an exploratory mixed method study
<p>Abstract</p> <p>Background</p> <p>To ensure carers of people with dementia receive support, community services increasingly use measures of caregiver (carer) burden to assess for unmet need. This study used Bradshaw's taxonomy of need to explore the link between measures of carer burden (normative need), service use (expressed need), and carer's stated need (felt need).</p> <p>Methods</p> <p>This mixed method exploratory study compared measures of carer burden with community services received and unmet needs, for 20 community-dwelling carer/care-recipient pairs.</p> <p>Results</p> <p>A simple one-item measure of carers' felt need for more services was significantly related to carer stress as measured on the GHQ-30. Qualitative data showed that there are many potential stressors for carers, other than those related to the care-giving role. We found a statistically significant rank correlation (p = 0.01) between carer's use of in-home respite and the care-recipient's cognitive and functional status which is likely to have been related to increased requirement for carer vigilance, effort and the isolation of spouse carers. Otherwise, there were no statistically significant relationships between carer burden or stress and level of service provision.</p> <p>Conclusion</p> <p>When carers are stressed or depressed, they can recognise that they would like more help from services, even if measures of carer burden and care recipient status do not clearly indicate unmet service needs. A question designed to elicit carer' <it>felt </it>need may be a better indicator of service need, and a red flag for recognising growing stress in carers of people with dementia. Assessment of service needs should recognise the fallibility of carer burden measures, given that carer stress may not only come from caring for someone with dementia, but can be significantly compounded by other life situations.</p
Photonic transistor and router using a single quantum-dotconfined spin in a single-sided optical microcavity
The future Internet is very likely the mixture of all-optical Internet with low power consumption and quantum Internet with absolute security guaranteed by the laws of quantum mechanics. Photons would be used for processing, routing and com-munication of data, and photonic transistor using a weak light to control a strong light is the core component as an optical analogue to the electronic transistor that forms the basis of modern electronics. In sharp contrast to previous all-optical tran-sistors which are all based on optical nonlinearities, here I introduce a novel design for a high-gain and high-speed (up to terahertz) photonic transistor and its counterpart in the quantum limit, i.e., single-photon transistor based on a linear optical effect: giant Faraday rotation induced by a single electronic spin in a single-sided optical microcavity. A single-photon or classical optical pulse as the gate sets the spin state via projective measurement and controls the polarization of a strong light to open/block the photonic channel. Due to the duality as quantum gate for quantum information processing and transistor for optical information processing, this versatile spin-cavity quantum transistor provides a solid-state platform ideal for all-optical networks and quantum networks
Comparative analysis of 1152 African-American and European-American men with prostate cancer identifies distinct genomic and immunological differences
Racial disparities in prostate cancer have not been well characterized on a genomic level. Here we show the results of a multi-institutional retrospective analysis of 1,152 patients (596 African-American men (AAM) and 556 European-American men (EAM)) who underwent radical prostatectomy. Comparative analyses between the race groups were conducted at the clinical, genomic, pathway, molecular subtype, and prognostic levels. The EAM group had increased ERG (P<0.001) and ETS (P=0.02) expression, decreased SPINK1 expression (P<0.001), and basal-like (P<0.001) molecular subtypes. After adjusting for confounders, the AAM group was associated with higher expression of CRYBB2, GSTM3, and inflammation genes (IL33, IFNG, CCL4, CD3, ICOSLG), and lower expression of mismatch repair genes (MSH2, MSH6) (p<0.001 for all). At the pathway level, the AAM group had higher expression of genes sets related to the immune response, apoptosis, hypoxia, and reactive oxygen species. EAM group was associated with higher levels of fatty acid metabolism, DNA repair, and WNT/beta-catenin signaling. Based on cell lines data, AAM were predicted to have higher potential response to DNA damage. In conclusion, biological characteristics of prostate tumor were substantially different in AAM when compared to EAM. Walter Rayford, Alp Tuna Beksac et al. investigated gene expression alterations in African-American and European-American men who underwent radical prostatectomy for prostate cancer. The observed differences include higher expression of inflammation genes and lower expression of mismatch repair genes in African-American men
A comparative study of dose distribution of PBT, 3D-CRT and IMRT for pediatric brain tumors
Quadriceps performance under activation of foot dorsal extension in healthy volunteers: an interventional cohort study
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