1,874 research outputs found

    Preoperative Hypertension

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    Purpose of Review This review will examine the implications for perioperative management of new hypertension guidelines and place these in the context of findings from recent large observational studies. Recent Findings Recent hypertension guidelines highlight the role of ambulatory blood pressure measurement with the implication that isolated preoperative blood pressure measurements are of limited value. There is emerging evidence from large observational studies that both preoperative and intraoperative hypotension are associated with increased risk. It is not clear if this is a particular concern for hypertensive patients. Summary Assessment of the hypertensive surgical patient should include blood pressure measurements taken using the correct technique. Preoperative blood pressures of less than 180/100 mmHg are not grounds for deferring surgery in the absence of active comorbid disease. Evidence to guide the perioperative management of patients with higher pressures is scanty and decisions should be made on a case-by-case basis

    Sensitivity of Pliocene Arctic climate to orbital forcing, atmospheric CO2 and sea ice albedo parameterisation

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    General circulation model (GCM) simulations of the mid-Pliocene Warm Period (mPWP, 3.264 to 3.025Myr ago) do not reproduce the magnitude of Northern Hemisphere high latitude surface air and sea surface temperature (SAT and SST) warming that proxy data indicate. There is also large uncertainty regarding the state of sea ice cover in the mPWP. Evidence for both perennial and seasonal mPWP Arctic sea ice is found through analyses of marine sediments, whilst in a multi-model ensemble of mPWP climate simulations, half of the ensemble simulated ice-free summer Arctic conditions. Given the strong influence that sea ice exerts on high latitude temperatures, an understanding of the nature of mPWP Arctic sea ice would be highly beneficial. Using the HadCM3 GCM, this paper explores the impact of various combinations of potential mPWP orbital forcing, atmospheric CO2concentrations and minimum sea ice albedo on sea ice extent and high latitude warming. The focus is on the Northern Hemisphere, due to availability of proxy data, and the large data–model discrepancies in this region. Changes in orbital forcings are demonstrated to be sufficient to alter the Arctic sea ice simulated by HadCM3 from perennial to seasonal. However, this occurs only when atmospheric CO2concentrations exceed 300 ppm. Reduction of the minimum sea ice albedo from 0.5 to 0.2 is also sufficient to simulate seasonal sea ice, with any of the combinations of atmospheric CO2and orbital forcing. Compared to a mPWP control simulation, monthly mean increases north of 60◦N of up to 4.2◦C (SST) and 9.8◦C (SAT) are simulated. With varying CO2, orbit and sea ice albedo values we are able to reproduce proxy temperature records that lean towards modest levels of high latitude warming, but other proxy data showing greater warming remain beyond the reach of our model. This highlights the importance of additional proxy records at high latitudes and ongoing efforts to compare proxy signals between sites

    New nuclear three-body clusters \phi{NN}

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    Binding energies of three-body systems of the type \phi+2N are estimated. Due to the strong attraction between \phi-meson and nucleon, suggested in different approaches, bound states can appear in systems like \phi+np (singlet and triplet) and \phi+pp. This indicates the principal possibility of the formation of new nuclear clusters

    Maxillary Sinus Augmentation With Recombinant Human Bone Morphogenetic Proteinâ 2 and Particulate Allograft Without an Absorbable Sponge: A Case Report

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141930/1/cap0175.pd

    Neoadjuvant chemotherapy and trastuzumab versus neoadjuvant chemotherapy followed by post-operative trastuzumab for patients with HER2-positive breast cancer

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    Neoadjuvant chemotherapy plus trastuzumab (NCT) increases the rate of pathological complete response (pCR) and event-free survival (EFS) compared to neoadjuvant chemotherapy (NC) alone in women with HER2 positive breast cancer (BC). pCR in this setting is associated with improved EFS. Whether NCT preferentially improves EFS in comparison to NC followed by adjuvant trastuzumab initiated postoperatively (NCAT) has not been addressed. Using clinical data from women with HER2 positive BC treated at 7 European institutions between 2007 and 2010 we sought to investigate the impact on breast cancer outcomes of concomitant (NCT) versus sequential (NCAT) treatment in HER2 positive early BC. The unadjusted hazard ratio (HR) for event free survival with NCT compared with NCAT was 0.63 (95% CI 0.37–1.08; p = 0.091). Multivariable analysis revealed that treatment group, tumour size and ER status were significantly associated with EFS from diagnosis. In the whole group NCT was associated with a reduced risk of an event relative to NCAT, an effect that was confined to ER negative (HR: 0.25; 95% CI, 0.10–0.62; p = 0.003) as opposed to ER positive tumours (HR: 1.07; 95% CI, 0.46–2.52; p = 0.869). HER2 positive/ER negative BC treated with NC gain greatest survival benefit when trastuzumab is administered in both the neoadjuvant and adjuvant period rather than in the adjuvant period alone. These data support the early introduction of targeted combination therapy in HER2 positive/ER negative BC

    Gene panel testing for breast cancer should not be used to confirm syndromic gene associations

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    Lensing in the Hercules Supercluster

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    We report Keck LRIS observations of an arc-like background galaxy near the center of Abell 2152 (z=0.043), one of the three clusters comprising the Hercules supercluster. The background object has a redshift z=0.1423 and is situated 25 arcsec north of the primary component of the A2152 brightest cluster galaxy (BCG). The object is about 15 arcsec in total length and has a reddening-corrected R-band magnitude of mR=18.55±0.03m_R = 18.55\pm0.03. Its spectrum shows numerous strong emission lines, as well as absorption features. The strength of the H-alpha emission would imply a star formation rate \SFR \approx 3h^{-2} \msun yr1^{-1} in the absence of any lensing. However, the curved shaped of this object and its tangential orientation along the major axis of the BCG suggest lensing. We model the A2152 core mass distribution including the two BCG components and the cluster potential. We present velocity and velocity dispersion profile measurements for the two BCG components and use these to help constrain the potential. The lens modeling indicates a likely magnification factor of 1.9\sim1.9 for the lensed galaxy, making A2152 the nearest cluster in which such significant lensing of a background source has been observed. Finally, we see evidence for a concentration of early-type galaxies at z=0.13z=0.13 near the centroid of the X-ray emission previously attributed to A2152. We suggest that emission from this background concentration is the cause of the offset of the X-ray center from the A2152 BCG. The background concentration and the dispersed mass of the Hercules supercluster could add further to the lensing strength of the A2152 cluster.Comment: Accepted for publication in AJ (January 2001). 9 pages; uses emulateapj.sty. The all-important "Figure 1" is included here in GIF format; for a version which includes Figure 1 as a high-resolution Postscript image, see: http://adcam.pha.jhu.edu/~jpb/a2152.ps.g

    Prevalence of frailty and reliability of established frailty instruments in adult elective colorectal surgical patients: a prospective cohort study

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    Purpose: Large population studies now demonstrate that frailty is prevalent in all adult age groups. Limited data exist on the association between frailty and surgical outcome in younger patients. The aim of the study was to explore the agreement between frailty identification tools and collect pilot data on their predictive value for frailty-associated outcomes in an adult surgical population. Study design: Prospective cohort study. Results: Frailty scores were recorded in 200 patients (91 men), mean (range) age 57 (18–92) years. The prevalence of prefrailty was 52%–67% and that of frailty 2%–32% depending on the instrument used. Agreement between the instruments was poor, kappa 0.08–0.17 in pairwise comparisons. Outcome data were available on 160 patients. Only the frailty phenotype was significantly associated with adverse outcomes, RR 6.1 (1.5–24.5) for postoperative complications. The three frailty scoring instruments studies had good sensitivity (Clinical Frailty Scale (CFS)—90%, Accumulation Deficit (AD)—96%, Frailty Phenotype (FP)—97%) but poor specificity (CFS—12%, AD—13%, FP—18%) for the prediction of postoperative complications. All three instruments were poorly predictive of adverse outcomes with likelihood ratios of CFS—1.02, AD—1.09 and FP—1.17. Conclusions: This study showed a significant prevalence of prefrailty and frailty in adult colorectal surgical patients of all ages. There was poor agreement between three established frailty scoring instruments. Our data do not support the use of current frailty scoring instruments in all adult colorectal surgical patients. However, the significant prevalence of prefrailty and frailty across all age groups of adult surgical patient justifies further research to refine frailty scoring in surgical patients

    The virtual haptic back: A simulation for training in palpatory diagnosis

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    <p>Abstract</p> <p>Background</p> <p>Models and simulations are finding increased roles in medical education. The Virtual Haptic Back (VHB) is a virtual reality simulation of the mechanical properties of the human back designed as an aid to teaching clinical palpatory diagnosis.</p> <p>Methods</p> <p>Eighty-nine first year medical students of the Ohio University College of Osteopathic Medicine carried out six, 15-minute practice sessions with the VHB, plus tests before and after the sessions in order to monitor progress in identifying regions of simulated abnormal tissue compliance. Students palpated with two digits, fingers or thumbs, by placing them in gimbaled thimbles at the ends of PHANToM 3.0<sup>® </sup>haptic interface arms. The interface simulated the contours and compliance of the back surface by the action of electric motors. The motors limited the compression of the virtual tissues induced by the palpating fingers, by generating counterforces. Users could see the position of their fingers with respect to the back on a video monitor just behind the plane of the haptic back. The abnormal region varied randomly among 12 locations between trials. During the practice sessions student users received immediate feedback following each trial, indicating either a correct choice or the actual location of the abnormality if an incorrect choice had been made. This allowed the user to feel the actual abnormality before going on to the next trial. Changes in accuracy, speed and Weber fraction across practice sessions were analyzed using a repeated measures analysis of variance.</p> <p>Results</p> <p>Students improved in accuracy and speed of diagnosis with practice. The smallest difference in simulated tissue compliance users were able to detect improved from 28% (SD = 9.5%) to 14% (SD = 4.4%) during the practice sessions while average detection time decreased from 39 (SD = 19.8) to 17 (SD = 11.7) seconds. When asked in anonymous evaluation questionnaires if they judged the VHB practice to be helpful to them in the clinical palpation and manual medicine laboratory, 41% said yes, 51% said maybe, and 8% said no.</p> <p>Conclusion</p> <p>The VHB has potential value as a teaching aid for students in the initial phases of learning palpatory diagnosis.</p
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