582 research outputs found

    Izazov eksperimenata virtualnog Comptonovog raspršenja iznad 8 GeV

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    We discuss the experimental issues confronting measurements of the virtualCompton-scattering (VCS) reaction ep→epγ with electron beams of energy 6 – 30 GeV. We specifically address the kinematics of deeply-virtual-Comptonscattering (deep inelastic scattering, with coincident detection of the exclusive real photon nearly parallel to the virtual photon direction) and large transverse momentum VCS (high energy VCS of arbitrary Q2, and the recoil proton emitted with high-momentum transverse to the virtual photon direction). We discuss the experimental equipment necessary for these measurements. For the deeply virtual Compton scattering, we emphasize the importance of the Bethe-Heitler – Compton interference terms that can be measured with the electron-positron (beam charge) asymmetry, and the electron beam helicity asymmetryRaspravljamo teško´ce s kojima se sučeljavaju mjerenja reakcija virtualnog Comptonovog raspršenja (VCS) ep→epγ pri energijama elektrona od 6 do 30 GeV. Posebno se razmatra kinematika duboko virtualnog Comptonovog raspršenja i VCS s velikim prijenosom impulsa. Raspravljamo mjerne uređaje koji su potrebni za takva mjerenja. Za duboko virtualno Comptonovo raspršenje, naglašavamo važnost Bethe-Heitlerovih interferentnih članova koji se mogu mjeriti asimetrijom elektronpozitron (naboj snopa) i asimetrijom heliciteta elektronskog snopa

    Izazov eksperimenata virtualnog Comptonovog raspršenja iznad 8 GeV

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    We discuss the experimental issues confronting measurements of the virtualCompton-scattering (VCS) reaction ep→epγ with electron beams of energy 6 – 30 GeV. We specifically address the kinematics of deeply-virtual-Comptonscattering (deep inelastic scattering, with coincident detection of the exclusive real photon nearly parallel to the virtual photon direction) and large transverse momentum VCS (high energy VCS of arbitrary Q2, and the recoil proton emitted with high-momentum transverse to the virtual photon direction). We discuss the experimental equipment necessary for these measurements. For the deeply virtual Compton scattering, we emphasize the importance of the Bethe-Heitler – Compton interference terms that can be measured with the electron-positron (beam charge) asymmetry, and the electron beam helicity asymmetryRaspravljamo teško´ce s kojima se sučeljavaju mjerenja reakcija virtualnog Comptonovog raspršenja (VCS) ep→epγ pri energijama elektrona od 6 do 30 GeV. Posebno se razmatra kinematika duboko virtualnog Comptonovog raspršenja i VCS s velikim prijenosom impulsa. Raspravljamo mjerne uređaje koji su potrebni za takva mjerenja. Za duboko virtualno Comptonovo raspršenje, naglašavamo važnost Bethe-Heitlerovih interferentnih članova koji se mogu mjeriti asimetrijom elektronpozitron (naboj snopa) i asimetrijom heliciteta elektronskog snopa

    Controlled light-matter coupling for a single quantum dot embedded in a pillar microcavity using far-field optical lithography

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    Using far field optical lithography, a single quantum dot is positioned within a pillar microcavity with a 50 nm accuracy. The lithography is performed in-situ at 10 K while measuring the quantum dot emission. Deterministic spectral and spatial matching of the cavity-dot system is achieved in a single step process and evidenced by the observation of strong Purcell effect. Deterministic coupling of two quantum dots to the same optical mode is achieved, a milestone for quantum computing.Comment: Modified version: new title, additional experimental data in figure

    Psychosocial Stress and Changes in Estimated Glomerular Filtration Rate Among Adults with Diabetes Mellitus

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    Background: Psychosocial stress has been hypothesized to impact renal changes, but this hypothesis has not been adequately tested. The aim of this study was to examine the relationship between psychosocial stress and estimated glomerular filtration rate (eGFR) and to examine other predictors of eGFR changes among persons with diabetes mellitus (DM). Methods: Data from a survey conducted in 2005 by a major health maintenance organization located in the southeastern part of the United States, linked to patients’ clinical and pharmacy records (n ¼ 575) from 2005 to 2008, was used. Study participants were working adults aged 25–59 years, diagnosed with DM but without advanced microvascular or macrovascular complications. eGFR was estimated using the Modification of Diet in Renal Disease equation. A latent psychosocial stress variable was created from five psychosocial stress subscales. Using a growth factor model in a structural equation framework, we estimated the association between psychosocial stress and eGFR while controlling for important covariates. Results: The psychosocial stress variable was not directly associated with eGFR in the final model. Factors found to be associated with changes in eGFR were age, race, insulin use, and mean arterial pressure. Conclusion: Among fairly healthy DM patients, we did not find any evidence of a direct association between psychosocial stress and eGFR changes after controlling for important covariates. Predictors of eGFR change in our population included age, race, insulin use, and mean arterial pressure

    Pass This Message Along: Self-edited Email Messages Promoting Colon Cancer Screening among Friends and Family

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    Encouraging communication within a social network may promote uptake of desired medical services or health behaviors. Little is known about the use of this approach to promote colorectal cancer (CRC) screening. We conducted in-person interviews with 438 insured adults ages 42-73 in Massachusetts, Hawaii, and Georgia. Participants were shown a sample message in which the sender shares that he has completed a colonoscopy and urges the recipient to discuss CRC screening with a doctor. We asked participants to edit the message to create one they would be willing to send to friends and family via email or postcard. Changes to the message were recorded. Edited text was analyzed for content and concordance with original message. The majority of participants (61.6%) modified the message; 14.2% added to or reframed the existing personalizing words (e.g. adding ‘because I love you’), 10.3% added urgency to the message (e.g. “please don’t delay”) and 8% added reassurance (e.g. “It’s really not that bad.”) Almost one in five (18.3%) deleted a negatively framed sentence on colon cancer risks. In 5.7% of cases, the meaning of at least one sentence was changed but only 2.7% created messages with factual inaccuracies. Modifiable messages transmitted within a social network offer a way for screened individuals to promote CRC screening. Further study is needed to identify the optimal combination of user-generated content and pre-written text, allowing for creation of messages that are acceptable to senders, persuasive and factually accurate

    The Association Between Low Health Literacy and Attitudes, Behaviors and Knowledge that Influence Engagement in Cancer Screening and Prevention Activities

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    Background: Health literacy is a complex, multifaceted phenomenon. While health literacy has historically been measured using instruments that assess reading and numeracy, comprehension of spoken information is also important. The purpose of this study was to identify adults with low health literacy using a multi-dimensional assessment of health literacy and to explore whether low health literacy was associated with variables likely to affect engagement in cancer prevention and screening activities. Methods: A random sample of English speaking adults aged 40-70 were invited to participate from: Kaiser Permanente Georgia, Hawaii, Colorado, and Fallon Community Health Plan Massachusetts. The Cancer Message Literacy Test-Listening, the Cancer Message Literacy Test-Reading, and the Lipkus Numeracy Scale were all used to assess aspects of health literacy. We also assessed self-efficacy, provider trust, and fatalism. Participants self-reported demographic data, health seeking behavior, and media use. Results: Out of 1074 adults, 48% were white, 73% were educated beyond high school, and 53% rated their health as very good or excellent. Compared to others, adults with low health literacy were more likely to avoid physician visits (p \u3c .001), more fatalistic about cancer (p Conclusions: In this population of insured adults, we identified differences among adults with low health literacy which may impact their engagement in cancer prevention and screening activities. These findings have important implications for health care interactions and public health communication. Understanding the reasons for these beliefs and behaviors may suggest ways to target and tailor communication for this vulnerable population

    Incidence of angioedema after initiation of angiotensin-converting enzyme inhibitors in adults with heart failure

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    Background: Angioedema, a potentially life-threatening adverse event associated with angiotensin-converting enzyme inhibitor (ACEI) use, occurs more often among Black patients than non-Black patients. Specific angioedema incidence rates (IRs) among heart failure (HF) patients initiating an ACEI are limited. Objectives: To provide estimates of angioedema incidence among HF patients initiating an ACEI, particularly among Black patients. Methods: We conducted a retrospective cohort study among adult (≥18 years) patients with HF who initiated ACEI use at 5 health care delivery systems within the Cardiovascular Research Network between July 2015 and May 2019. We required patients to have ≥12 months of continuous medical and prescription drug coverage and no ACEI dispensings in the 1 year before treatment initiation. Our primary outcome was serious angioedema, defined as a primary or secondary diagnosis of ICD-9 code 995.1 (‘Angioneurotic edema not elsewhere classified’) or ICD-10 codes in the T78.3 series (‘Angioneurotic edema’) during hospitalization. Our secondary out-come was ‘any angioedema’, which included serious angioedema and non-serious angioedema that was diagnosed in the outpatient setting. We followed patients from ACEI initiation until first angioedema diagnosis or a censoring event (treatment discontinuation, initiation of another renin-angiotensin-aldosterone system blocking agent, disenrollment, death, or end of 365-day follow-up or study). We calculated crude IRs and exact 95% confidence intervals (CI) for angioedema among HF patients initiating an ACEI. Results: We identified 14 ,241 ACEI users, of which 6,156 (43 .2%)were women and 2,105 (15%) were self-reported Black. Mean age was 70 ± 14 years. We observed 6 serious angioedema events overall (IR: 0.8/1,000 person-years (PYs), 95% CI: 0.3-1.7), with 2 events occurring among Black patients (IR: 1.8/1,000 PYs, 95%CI: 0.2-6.5) and 4 events among non-Black patients (IR: 0.6/1,000PYs, 95% CI: 0.2-1.5). We observed 43 angioedema events overall (IR: 5.4/1,000 PYs, 95% CI: 3.9-7.3), with 21 events occurring among Black patients (IR: 19/1,000 PYs, 95% CI: 11.8-29.1) and 22 events among non-Black patients (IR: 3.2/1,000 PYs, 95%CI: 2.0-4.9). Conclusions: Our estimate of angioedema incidence among HF patients who initiated an ACEI (5.4 events/1,000 PYs) is slightly higher than a previously published estimate (3.3/1,000 PYs) among a similarly-defined population identified through administrative claims data. Similar to prior reports, we found a higher incidence of angioedema, both serious and non-serious, among Black ACEI users than among non-black ACEI users

    Health Literacy and Cancer Prevention: It’s Not What You Say It’s What They Hear

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    Background: A growing body of literature documents the relationship between health literacy and important health behaviors and outcomes. Most research to date has focused on print literacy–few studies have examined literacy with respect to spoken information (“spoken health literacy”). We sought to examine the extent to which responses to physician advice about cancer prevention and screening were associated with spoken health literacy. Methods: Participants listened to 3 simulated physician-patient discussions addressing: 1) Prostate Specific Antigen (PSA) testing; 2) tamoxifen for breast cancer prevention; and 3) colorectal cancer (CRC) screening. The physician provided information on risks and benefits but did not endorse one course of action. Post-vignette questions assessed understanding and reactions to the physician’s advice. Participants had previously completed the Cancer Message Literacy Test-Listening (CMLT-L), a measure of spoken health literacy. Bivariate analyses examined the relationship between CMLT-L scores and comprehension, attitudes, and behavioral intentions. Results: Four hundred thirty-eight adults from 3 HMORN sites participated. Comprehension: Post-vignette comprehension scores were correlated with CMLT-L scores (r=0.62, p Discussion: The ability to understand spoken information is a critical component of health literacy. In this study, spoken health literacy influenced patients’ comprehension of, and reaction to spoken health information provided by a physician. The findings that participants scoring in the lowest quartile on the CMLT-L were more likely to respond favorably to physician advice on cancer prevention but were less likely to comprehend content of the vignettes, may indicate that physician mention of a prevention service is interpreted as endorsement of a prevention service in the absence of a full understanding of its risks and benefits
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