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A method of chemical-shift imaging is described using the invariance of chemical shifts to changes in magnetic field gradients used for frequency encoding of position in imaging. This enables separation of the effects on the observed signal of chemical shift from the effects of different positions along the imaging gradient when the signal is observed with different gradients. A simple implementation for a two-line spectrum is presented using signals observed with normal and reversed imaging gradients. This is used to create "fat" and "water" images of the thigh. 相似文献
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A T Turrisi D J Glover 《International journal of radiation oncology, biology, physics》1990,19(6):1473-1479
In limited small cell lung cancer (LSCLC), the high local failure rate of chemotherapy by itself (60-100%) and with the addition of external beam radiotherapy (approximately 30%) has led to investigation of methods to improve local control. To that end, we integrated Platinum 60 mg/m2, d. 1, 22 and Etoposide 120 mg/m2, d. 4, 6, & 8; 25, 27 & 29 with concurrent twice-daily 150 cGy (total dose: 4500 cGy). Of 32 consecutively referred patients, 4 with variant histology, 31 were evaluable for toxicity, response, and survival. Two of 4 variant histology patients responded, and 27 of 27 pure small cell responded, p = 0.005. CT scans were inaccurate at forecasting survival. Of 17/32 patients considered "positive," 59% of these were survivors; of those considered "negative," 47% were survivors, p = N.S. Radiation portals were volumetrically conservative; the supraclavicular fossa was included infrequently and the contralateral hilum not at all. Local failure occurred in only 1/27 patients (4%). All four variant patients failed locally, p = 0.001. With a median follow-up of 43 months, the actuarial disease-free survival remains nearly 50%. Variant histology is more predictive of local control than the physical factors of dose or volume. 相似文献
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Walker N Howe C Bullen C Grigg M Glover M McRobbie H Laugesen M Parag V Whittaker R 《Addiction (Abingdon, England)》2012,107(10):1857-1867
Aim To determine the combined effect of very low nicotine content (VLNC) cigarettes and usual Quitline care [nicotine replacement therapy (NRT) and behavioural support] on smoking abstinence, in smokers motivated to quit. Design Single‐blind, parallel randomized trial. Setting New Zealand. Participants Smokers who called the Quitline for quitting support were randomized to either VLNC cigarettes to use whenever they had an urge to smoke for up to 6 weeks after their quit date, in combination with usual Quitline care (8 weeks of NRT patches and/or gum or lozenges, plus behavioural support) or to usual Quitline care alone. Measurements The primary outcome was 7‐day point‐prevalence smoking abstinence 6 months after quit day. Secondary outcomes included continuous abstinence, cigarette consumption, withdrawal, self‐efficacy, alcohol use, serious adverse events and views on the use of the VLNC cigarettes at 3 and 6 weeks and 3 and 6 months. Findings A total of 1410 participants were randomized (705 in each arm), with a 24% loss to follow‐up at 6 months. Participants in the intervention group were more likely to have quit smoking at 6 months compared to the usual care group [7‐day point‐prevalence abstinence 33 versus 28%, relative risk (RR) = 1.18, 95% confidence interval (CI): 1.01, 1.39, P = 0.037; continuous abstinence 23 versus 15%, RR = 1.50, 95% CI: 1.20, 1.87, P = 0.0003]. The median time to relapse in the intervention group was 2 months compared to 2 weeks in the usual care group (P < 0.0001). Conclusions Addition of very low nicotine content cigarettes to standard Quitline smoking cessation support may help some smokers to become abstinent. 相似文献
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Masahiko Yazawa Orsolya Cseprekal Ryan A. Helmick Manish Talwar Vasanthi Balaraman Pradeep S. B. Podila Uchenna A. Agbim Benedict Maliakkal Sallyanne Fossey Sanjaya K. Satapathy Keiichi Sumida Csaba P. Kovesdy Satheesh Nair James D. Eason Miklos Z. Molnar 《Transplant international》2020,33(2):202-215
There is a dearth of published data regarding the presence of post-transplant donor-specific antibodies (DSA), especially C1q-binding DSA (C1q+DSA), and patient and kidney allograft outcomes in simultaneous liver–kidney transplant (SLKT) recipients. We conducted a retrospective cohort study consisted of 85 consecutive SLKT patients between 2009 and 2018 in our center. Associations between presence of post-transplant DSA, including persistent and/or newly developed DSA and C1q+DSA, and all-cause mortality and the composite outcome of mortality, allograft kidney loss, and antibody-mediated rejection were examined using unadjusted and age and sex-adjusted Cox proportional hazards and time-dependent regression models. The mean age at SLKT was 56 years and 60% of the patients were male. Twelve patients (14%) had post-transplant DSA and seven patients (8%) had C1q+DSA. The presence of post-transplant DSA was significantly associated with increased risk of mortality (unadjusted model: Hazard Ratio (HR) = 2.72, 95% confidence interval (CI): 1.06–6.98 and adjusted model: HR = 3.20, 95% CI: 1.11–9.22) and the composite outcome (unadjusted model: HR = 3.18, 95% CI: 1.31–7.68 and adjusted model: HR = 3.93, 95% CI: 1.39–11.10). There was also higher risk for outcomes in recipients with C1q+DSA compared the ones without C1q+DSA. Post-transplant DSA is significantly associated with worse patient and kidney allograft outcomes in SLKT. Further prospective and large cohort studies are warranted to better assess these associations. 相似文献
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Benedict C. Creagh-Brown Gregory J. Quinlan Timothy W. Evans Anne Burke-Gaffney 《Intensive care medicine》2010,36(10):1644-1656