172 research outputs found

    High‐speed Intraoperative Assessment of Breast Tumor Margins by Multimodal Ultrasound and Photoacoustic Tomography

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    Conventional methods for breast tumor margins assessment need a long turnaround time, which may lead to re‐operation for patients undergoing lumpectomy surgeries. Photoacoustic tomography (PAT) has been shown to visualize adipose tissue in small animals and human breast. Here, we demonstrate a customized multimodal ultrasound and PAT system for intraoperative breast tumor margins assessment using fresh lumpectomy specimens from 66 patients. The system provides the margin status of the entire excised tissue within 10 minutes. By subjective reading of three researchers, the results show 85.7% [95% confidence interval (CI), 42.0% ‐ 99.2%] sensitivity and 84.6% (95% CI, 53.7% ‐ 97.3%) specificity, 71.4% (95% CI, 30.3% ‐ 94.9%) sensitivity and 92.3% (95% CI, 62.1% ‐ 99.6%) specificity, and 100% (95% CI, 56.1% ‐ 100%) sensitivity and 53.9% (95% CI, 26.1% ‐ 79.6%) specificity respectively when cross‐correlated with post‐operational histology. Furthermore, a machine learning‐based algorithm is deployed for margin assessment in the challenging ductal carcinoma in situ tissues, and achieved 85.5% (95% CI, 75.2% ‐ 92.2%) sensitivity and 90% (95% CI, 79.9% ‐ 95.5%) specificity. Such results present the potential of using mutlimodal ultrasound and PAT as a high‐speed and accurate method for intraoperative breast tumor margins evaluation

    Are Surgeons Behind the Scientific Eight Ball: Delayed Acquisition of the NIH K08 Mentored Career Development Award

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    Background: Surgery residents complete their research training early in residency. Non-surgical trainees typically have research incorporated toward the last two years of their fellowship, conferring an advantage to apply for grants with recent research experience and preliminary data. Methods: The NIH RePORTER database was queried for K08 awardees trained in medicine, pediatrics, and surgery from 2013 to 2017. 406 K08 recipients were identified and time from completion of clinical training to achieving a K08 award was measured. Data were compared using ANOVA and expressed as mean. P < 0.05 was considered significant. Results: Surgeons took longer to obtain a K08 than those trained in internal medicine (surgery = 3.7 years, internal medicine = 2.58 years p < 0.0001)). All K08 recipients without a PhD took longer to obtain a K08 than recipients with a PhD (MD = 3.50 years and MD/PhD = 2.42 years (p=<0.0001). Conclusions: Surgeons take longer to achieve a K08 award than clinicians trained in internal medicine, possibly due to an inherent disadvantage in training structure

    A Competency-based Laparoscopic Cholecystectomy Curriculum Significantly Improves General Surgery Residents’ Operative Performance and Decreases Skill Variability: Cohort Study

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    Objective: To demonstrate the feasibility of implementing a CBE curriculum within a general surgery residency program and to evaluate its effectiveness in improving resident skill. Summary of Background Data: Operative skill variability affects residents and practicing surgeons and directly impacts patient outcomes. CBE can decrease this variability by ensuring uniform skill acquisition. We implemented a CBE LC curriculum to improve resident performance and decrease skill variability. Methods: PGY-2 residents completed the curriculum during monthly rotations starting in July 2017. Once simulator proficiency was reached, residents performed elective LCs with a select group of faculty at 3 hospitals. Performance at curriculum completion was assessed using LC simulation metrics and intraoperative operative performance rating system scores and compared to both baseline and historical controls, comprised of rising PGY-3s, using a 2-sample Wilcoxon rank-sum test. PGY-2 group’s performance variability was compared with PGY-3s using Levene robust test of equality of variances; P < 0.05 was considered significant. Results: Twenty-one residents each performed 17.52 ± 4.15 consecutive LCs during the monthly rotation. Resident simulated and operative performance increased significantly with dedicated training and reached that of more experienced rising PGY-3s (n = 7) but with significantly decreased variability in performance (P = 0.04). Conclusions: Completion of a CBE rotation led to significant improvements in PGY-2 residents’ LC performance that reached that of PGY-3s and decreased performance variability. These results support wider implementation of CBE in resident training

    Replication and Explorations of High-Order Epistasis Using a Large Advanced Intercross Line Pedigree

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    Dissection of the genetic architecture of complex traits persists as a major challenge in biology; despite considerable efforts, much remains unclear including the role and importance of genetic interactions. This study provides empirical evidence for a strong and persistent contribution of both second- and third-order epistatic interactions to long-term selection response for body weight in two divergently selected chicken lines. We earlier reported a network of interacting loci with large effects on body weight in an F2 intercross between these high– and low–body weight lines. Here, most pair-wise interactions in the network are replicated in an independent eight-generation advanced intercross line (AIL). The original report showed an important contribution of capacitating epistasis to growth, meaning that the genotype at a hub in the network releases the effects of one or several peripheral loci. After fine-mapping of the loci in the AIL, we show that these interactions were persistent over time. The replication of five of six originally reported epistatic loci, as well as the capacitating epistasis, provides strong empirical evidence that the originally observed epistasis is of biological importance and is a contributor in the genetic architecture of this population. The stability of genetic interaction mechanisms over time indicates a non-transient role of epistasis on phenotypic change. Third-order epistasis was for the first time examined in this study and was shown to make an important contribution to growth, which suggests that the genetic architecture of growth is more complex than can be explained by two-locus interactions only. Our results illustrate the importance of designing studies that facilitate exploration of epistasis in populations for obtaining a comprehensive understanding of the genetics underlying a complex trait

    Genome-Wide Effects of Long-Term Divergent Selection

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    To understand the genetic mechanisms leading to phenotypic differentiation, it is important to identify genomic regions under selection. We scanned the genome of two chicken lines from a single trait selection experiment, where 50 generations of selection have resulted in a 9-fold difference in body weight. Analyses of nearly 60,000 SNP markers showed that the effects of selection on the genome are dramatic. The lines were fixed for alternative alleles in more than 50 regions as a result of selection. Another 10 regions displayed strong evidence for ongoing differentiation during the last 10 generations. Many more regions across the genome showed large differences in allele frequency between the lines, indicating that the phenotypic evolution in the lines in 50 generations is the result of an exploitation of standing genetic variation at 100s of loci across the genome

    Learning physical examination skills outside timetabled training sessions: what happens and why?

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    Lack of published studies on students’ practice behaviour of physical examination skills outside timetabled training sessions inspired this study into what activities medical students undertake to improve their skills and factors influencing this. Six focus groups of a total of 52 students from Years 1–3 using a pre-established interview guide. Interviews were recorded, transcribed and analyzed using qualitative methods. The interview guide was based on questionnaire results; overall response rate for Years 1–3 was 90% (n = 875). Students report a variety of activities to improve their physical examination skills. On average, students devote 20% of self-study time to skill training with Year 1 students practising significantly more than Year 3 students. Practice patterns shift from just-in-time learning to a longitudinal selfdirected approach. Factors influencing this change are assessment methods and simulated/real patients. Learning resources used include textbooks, examination guidelines, scientific articles, the Internet, videos/DVDs and scoring forms from previous OSCEs. Practising skills on fellow students happens at university rooms or at home. Also family and friends were mentioned to help. Simulated/real patients stimulated students to practise of physical examination skills, initially causing confusion and anxiety about skill performance but leading to increased feelings of competence. Difficult or enjoyable skills stimulate students to practise. The strategies students adopt to master physical examination skills outside timetabled training sessions are self-directed. OSCE assessment does have influence, but learning takes place also when there is no upcoming assessment. Simulated and real patients provide strong incentives to work on skills. Early patient contacts make students feel more prepared for clinical practice

    Psychology and aggression

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68264/2/10.1177_002200275900300301.pd
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