儿童体位性心动过速综合征的诊断

儿童体位性心动过速综合征（postural tachycardia syndrome， POTS）是儿童时期晕厥最常见的病因之一， 主要表现为体位改变或直立后头晕、 头痛、 心悸、面色改变、视物模糊、 乏力、 晕厥等。通过直立或直立倾斜试验（HUTT）， 可以对儿童体位性心动过速综合征（POTS）作出明确诊断， 从而达到有效的早期治疗， 减少儿童晕厥的发生。     

Trends in skin prick test according to seasons: Results of a Korean multi-center study

ObjectiveAllergy is a very common condition. Allergic disease is highly affected by environmental changes. Conditions of the four seasons can change dramatically in Republic of Korea (ROK). To assess changes in rates of aeroallergen positivity according to seasons and environmental factors (temperature, humidity, and precipitation).MaterialsA total of 20 hospitals were selected based on population distribution in ROK. A skin prick test (SPT) panel comprising 55 aeroallergens was distributed to 18 hospitals for a prospective study. Results from SPTs done in 2006 and 2010 were collected and analyzed retrospectively from 20 hospitals and 2014/2015 SPT (from June 2014 to May 2015) results from 18 hospitals were collected prospectively.ResultsWe compared allergen-positive rates among seasons. Positive test rates for several pollens and house dust mites increased significantly in spring and fall. Pollens positive rate varied significantly according to temperature, precipitation, and humidity while mite allergens were less susceptible to environment.ConclusionThere are four distinct seasons in ROK. The positivity of pollen allergens were especially affected by temperature and precipitation in spring. House dust mites were less affected by seasons, temperature, precipitation, and humidity less than pollen. Therefore, regular follow-up and re-evaluation of allergic test are essential considering changes of seasons and environment for acceptable diagnosis and treatment.     

Mobile Brain/Body Imaging of cognitive-motor impairment in multiple sclerosis: Deriving EEG-based neuro-markers during a dual-task walking study

ObjectiveIndividuals with a diagnosis of multiple sclerosis (MS) often present with cognitive and motor deficits, and thus the ability to perform tasks that rely on both domains may be particularly impaired. Yet, dual-task walking studies yield mixed results. Individual variance in the ability to cope with brain insult and mobilize additional brain resources may contribute to mixed findings.MethodsTo test this hypothesis, we acquired event-related potentials (ERP) in individuals with MS and healthy controls (HCs) performing a Go/NoGo task while sitting (i.e., single task) or walking (i.e., dual-task) and looked at the relationship between task related modulation of the brain response and performance.ResultsOn the Go/NoGo task the MS group showed dual-task costs when walking, whereas HCs showed a dual-task benefit. Further, whereas the HC group showed modulation of the brain response as a function of task load, this was not the case in the MS group. Analysis for the pooled sample revealed a positive correlation between load-related ERP effects and dual-task performance.ConclusionsThese data suggest a neurophysiological marker of cognitive-motor dysfunction in MS.SignificanceUnderstanding neural processes underlying dual-task walking will help identify objective brain measurements of real-world issues and may improve assessment of MS.     

以机油为分散剂高温热解人发合成新型碳点及其生物效应研究

目的以机油为分散剂高温热解人发后发现新型纳米碳点,通过动物实验评价了该碳点的生物效应。方法利用高温热解法对人发和机油进行炭化,对炭化产物进行萃取、过滤分离和透析得到一种具有水溶性的新型物质碳点,并命名为JYRF-CDs。利用透射电子显微镜(TEM)、高分辨透射电子显微镜(HR-TEM)、紫外-可见分光光谱、傅里叶变换红外光谱、荧光光谱、X射线光电子能谱分析(XPS)等多种方法对JYRF-CDs进行表征,利用小鼠单核巨噬细胞RAW264.7细胞进行CCK-8毒性实验来评价JYRF-CDs的安全性,并通过小鼠耳肿胀实验和小鼠醋酸扭体实验对JYRF-CDs的生物效应进行评价。结果 JYRF-CDs外形为类球形,粒径均匀分布在1.8～3.6 nm,晶格间距为0.219 7 nm。细胞毒性实验结果显示,JYRF-CDs具有低毒性,动物实验结果表明JYRF-CDs具有良好的抗炎和镇痛作用。结论首次以机油为分散剂高温热解人发后发现一种全新的碳点JYRF-CDs,以JYRF-CDs为突破口,更加明确阐释以机油为分散剂高温热解人发后炭化产物具有生物效应的物质基础,为纳米类成分的研究提供了一种新方法。     

Mechanical and morphological determinants of peak power output in elite cyclists

Mechanical peak power output (PPO) is a determinant of performance in sprint cycling. The purpose of this study was to examine the relationship between PPO and putative physiological determinants of PPO in elite cyclists, and to compare sprint performance between elite sprint and endurance cyclists. Thirty-five elite cyclists (18 endurance; 17 sprint) performed duplicate sprint cycling laboratory tests to establish PPO and its mechanical components. Quadriceps femoris (Q_VOL) and hamstring muscle volume (HAM_VOL) were assessed with MRI, vastus lateralis pennation angle (Pθ_VL) and fascicle length (FL_VL) were determined with ultrasound imaging, and neuromuscular activation of three muscles was assessed using EMG at PPO during sprint cycling. For the whole cohort, there was a wide variability in PPO (range 775-2025 W) with very large, positive, bivariate relationships between PPO and Q_VOL (r = .87), HAM_VOL (r = .71), and Pθ_VL (r = .81). Step-wise multiple regression analysis revealed that 87% of the variability in PPO between cyclists was explained by two variables Q_VOL (76%) and Pθ_VL (11%). The sprint cyclists had greater PPO (+61%; P < .001 vs endurance), larger Q_VOL (P < .001), and BF_VOL (P < .001) as well as more pennate vastus lateralis muscles (P < .001). These findings emphasize the importance of quadriceps muscle morphology for sprint cycling events.