胸段食管癌累及野放疗与扩大野放疗对危及器官的辐射剂量学分析

目的 研究胸段食管癌逆向调强放射治疗（IMRT）中累及野照射与扩大野照射对危及器官（OAR）受照剂量的影响。方法 40例胸段食管癌患者分别行累及野靶区勾画和扩大野靶区勾画并勾画危及器官，制定IMRT计划，评估2个计划的靶区适形指数（CI）和均匀性指数（HI）及危及器官的剂量学参数，剂量学参数比较采用配对t检验。结果 2种计划的PTV均能满足处方剂量要求，PTV在CI、HI上相近（P = 0.317、0.130）。两组间平均肺剂量、两肺V₅、两肺V₂₀、两肺V₃₀、脊髓D_mean、心脏D_mean、心脏D_max、心脏V₃₀、心脏V₄₀、心脏V₆₀差异均存在统计学意义（P < 0.01）。结论 胸段食管癌患者行累及野照射与扩大野比较，可降低正常器官的受照剂量，从而降低放射性损伤风险。     

Validation of the Modena bleeding score in endoscopic sinus surgery

IntroductionThe Modena bleeding score is a categorical rating scale that allows the assessment of the surgical field in relation to bleeding during endoscopic surgery. It has recently been presented and validated in the field of endoscopic ear surgery by the present authors. The Modena bleeding score provides five grades for rating the surgical field during endoscopic procedures (from grade 1 ? no bleeding to grade 5 ? bleeding that prevents every surgical procedure except those dedicated to bleeding control).ObjectiveThe aim of this study was to validate the Modena bleeding score in the setting of endoscopic sinus surgery.MethodsFifteen three-minute videos of endoscopic sinus surgery procedures (each containing three bleeding situations) were evaluated by 15 specialists, using the Modena bleeding score. Intra and inter-rater reliability were assessed, and the clinical validity of the Modena bleeding score was calculated using a referent standard.ResultsThe data analysis showed an intra-rater reliability ranging from 0.6336 to 0.861. The inter-rater reliability ranged from 0.676 to 0.844. The clinical validity was α = 0.70; confidence limits: 0.64 ? 0.75, corresponding to substantial agreement.ConclusionThe Modena bleeding score is an effective method to score bleeding during endoscopic sinus surgery. Its application in future research could facilitate the performance and efficacy assessment of surgical techniques, materials or devices aimed to bleeding control during endoscopic sinus surgery.     

Comparison of quantitative susceptibility mapping methods on evaluating radiation-induced cerebral microbleeds and basal ganglia at 3T and 7T

Quantitative susceptibility mapping (QSM) has the potential for being a biomarker for various diseases because of its ability to measure tissue susceptibility related to iron deposition, myelin, and hemorrhage from the phase signal of a T₂*-weighted MRI. Despite its promise as a quantitative marker, QSM is faced with many challenges, including its dependence on preprocessing of the raw phase data, the relatively weak tissue signal, and the inherently ill posed relationship between the magnetic dipole and measured phase. The goal of this study was to evaluate the effects of background field removal and dipole inversion algorithms on noise characteristics, image uniformity, and structural contrast for cerebral microbleed (CMB) quantification at both 3T and 7T. We selected four widely used background phase removal and five dipole field inversion algorithms for QSM and applied them to volunteers and patients with CMBs, who were scanned at two different field strengths, with ground truth QSM reference calculated using multiple orientation scans. 7T MRI provided QSM images with lower noise than did 3T MRI. QSIP and VSHARP + iLSQR achieved the highest white matter homogeneity and vein contrast, with QSIP also providing the highest CMB contrast. Compared with ground truth COSMOS QSM images, overall good correlations between susceptibility values of dipole inversion algorithms and the COSMOS reference were observed in basal ganglia regions, with VSHARP + iLSQR achieving the susceptibility values most similar to COSMOS across all regions. This study can provide guidance for selecting the most appropriate QSM processing pipeline based on the application of interest and scanner field strength.     

知母种子质量分级标准的研究

目的:研究制定知母种子的质量分级标准。方法:通过对不同产地20个批次知母种子的净度、千粒质量、含水量、生活力、发芽率等指标测定和外观形态观察,利用Excel 2010、SPSS 20.0软件对以上数据进行相关分析、主成分以及K-均值聚类分析,初步确定知母种子质量分级指标和分级标准,且以各等级知母种子分别在田间对比种植,通过测定1年产苗量,2年药材产量及有效成分含量,验证知母种子质量分级标准的合理性。结果:Ⅰ级知母种子发芽率不低于85%,千粒质量不低于7.5 g,净度不低于95%;Ⅱ级知母种子发芽率不低于70%,千粒质量不低于7.0 g,净度不低于85%;Ⅲ级知母种子发芽率不低于65%,千粒质量不低于6.0 g,净度不低于80%;各级种子含水量均小于10%。结论:发芽率和千粒质量为知母种子质量分级标准的主要指标,净度和含水量为参考指标。不同等级知母种子种植后对知母种苗产量、药材产量及质量会有显著影响。该研究制定的知母种子质量分级标准科学可行、符合生产实际,为知母的种子质量评价和规范化栽培提供参考依据。     

The place of therapy: between lab and field in the psychoanalytic office

This article builds on recent scholarship in medicine, science and technology illuminating the role of place and materiality in medical work. Drawing on ethnographic observations and qualitative interviews with US psychiatrists, psychologists and clinical social workers, I examine how the therapy office shapes psychoanalytic psychotherapists’ efforts to understand their patients’ unconscious conflicts. The concepts of ‘laboratory’ and ‘field’ frame my discussion of the material set up of the clinical room and the relational practices it fosters. I show that psychoanalytic practitioners try to approximate ‘laboratory conditions’ that insulate patients’ problems from their everyday contexts and ensure a sense of stability. I also demonstrate that these clinicians’ work depends on revealing personal preferences in the therapy room and fostering therapeutic relationships that resemble those in patients’ everyday lives, making the office akin to the ‘field’. The office thus becomes epistemically productive through therapists’ management of the paradoxical relationship between laboratory and field.     

Electrophysiological differences between upper and lower limb movements in the human subthalamic nucleus

ObjectiveFunctional processes in the brain are segregated in both the spatial and spectral domain. Motivated by findings reported at the cortical level in healthy participants we test the hypothesis in the basal ganglia of Parkinson’s disease patients that lower frequency beta band activity relates to motor circuits associated with the upper limb and higher beta frequencies with lower limb movements.MethodsWe recorded local field potentials (LFPs) from the subthalamic nucleus using segmented “directional” DBS leads, during which patients performed repetitive upper and lower limb movements. Movement-related spectral changes in the beta and gamma frequency-ranges and their spatial distributions were compared between limbs.ResultsWe found that the beta desynchronization during leg movements is characterised by a strikingly greater involvement of higher beta frequencies (24–31 Hz), regardless of whether this was contralateral or ipsilateral to the limb moved. The spatial distribution of limb-specific movement-related changes was evident at higher gamma frequencies.ConclusionLimb processing in the basal ganglia is differentially organised in the spectral and spatial domain and can be captured by directional DBS leads.SignificanceThese findings may help to refine the use of the subthalamic LFPs as a control signal for adaptive DBS and neuroprosthetic devices.