Characterizing reward system neural trajectories from adolescence to young adulthood

Mixed findings exist in studies comparing brain responses to reward in adolescents and adults. Here we examined the trajectories of brain response, functional connectivity and task-modulated network properties during reward processing with a large-sample longitudinal design. Participants from the IMAGEN study performed a Monetary Incentive Delay task during fMRI at timepoint 1 (T1; n = 1304, mean age=14.44 years old) and timepoint 2 (T2; n = 1241, mean age=19.09 years). The Alcohol Use Disorders Identification Test (AUDIT) was administrated at both T1 and T2 to assess a participant’s alcohol use during the past year. Voxel-wise linear mixed effect models were used to compare whole brain response as well as functional connectivity of the ventral striatum (VS) during reward anticipation (large reward vs no-reward cue) between T1 and T2. In addition, task-modulated networks were constructed using generalized psychophysiological interaction analysis and summarized with graph theory metrics. To explore alcohol use in relation to development, participants with no/low alcohol use at T1 but increased alcohol use to hazardous use level at T2 (i.e., participants with AUDIT≤2 at T1 and ≥8 at T2) were compared against those with consistently low scores (i.e., participants with AUDIT≤2 at T1 and ≤7 at T2). Across the whole sample, lower brain response during reward anticipation was observed at T2 compared with T1 in bilateral caudate nucleus, VS, thalamus, midbrain, dorsal anterior cingulate as well as left precentral and postcentral gyrus. Conversely, greater response was observed bilaterally in the inferior and middle frontal gyrus and right precentral and postcentral gyrus at T2 (vs. T1). Increased functional connectivity with VS was found in frontal, temporal, parietal and occipital regions at T2. Graph theory metrics of the task-modulated network showed higher inter-regional connectivity and topological efficiency at T2. Interactive effects between time (T1 vs. T2) and alcohol use group (low vs. high) on the functional connectivity were observed between left middle temporal gyrus and right VS and the characteristic shortest path length of the task-modulated networks. Collectively, these results demonstrate the utility of the MID task as a probe of typical brain response and network properties during development and of differences in these features related to adolescent drinking, a reward-related behaviour associated with heightened risk for future negative health outcomes.     

基层胸痛中心 AMI 患者救治延迟影响因素

〔摘 要〕 目的：探究基层胸痛中心急性心肌梗死（AMI）患者救治延迟影响因素。方法：选取 2018 年 7 月至 2020 年 6 月 清远市清城区人民医院胸痛中心收治的 AMI 患者 120 例作为研究对象，采取 Logistic 多因素回归分析法分析救治延迟的影 响因素。结果：年龄、发病时机、糖尿病、文化程度、居住地区、就医决策、选择再灌注策略为院前院内治疗延迟时间的 独立危险因素。结论：在实际临床工作中，应重点优化对高龄、患有糖尿病、居住在农村的 AMI 患者的救治流程，选择适 合的再灌注策略，缩短需经皮冠状动脉介入术的患者转运时间、减少心肌缺血总时间。     

Cognitive spatial-motor processes

Summary We studied the activity of 123 cells in the arm area of the motor cortex of three rhesus monkeys while the animals performed a 2-dimensional (2-D) step-tracking task with or without a delay interposed between a directional cue and a movement triggering signal. Movements of equal amplitude were made in eight directions on a planar working surface, from a central point to targets located equidistantly on a circle. The appearance of the target served as the cue, and its dimming, after a variable period of time (0.5–3.2 s), as the go stimulus to trigger the movement to the target; in a separate task, the target light appeared dim and the monkey moved its hand towards it without waiting. Population histograms were constructed for each direction after the spike trains of single trials were aligned to the onset of the cue. A significant increase (3–4×) in the population activity was observed 80–120 ms following the cue onset; since the minimum delay was 500 ms and the average reaction time approximately 300 ms, this increase in population activity occurred at least 680–720 ms before the onset of movement. A directional analysis (Georgopoulos et al. 1983, 1984) of the changes in population activity revealed that the population vector during the delay period pointed in the direction of movement that was to be made later.     

Movement preparation and working memory: a behavioural dissociation

We can cross temporal sensorimotor contingencies by remembering sensory events or by anticipating motor responses. Here we tested the hypothesis that sensory and motor representations can be accessed according to different temporal dynamics. We predicted that the manipulation of movement representations would lead to a performance independent from the length of a delay interposed between sensory instructions and behavioural responses. Conversely, we expected a delay-dependent performance whenever temporary storage of sensory information was necessary to solve the task. We have measured reaction times and error rate in subjects performing a delayed non-matching to sample task. Task contingencies rather than explicit instructions ensured that either sensory or motor representations were used to cross the delay period on each trial. We tested our hypothesis by manipulating the length of the delays between stimulus presentation and behavioural response. We found that carrying sensory material over temporal gaps affects performance as a non-linear function of time, whereas movement representations remain robust over a wide range of delays. This novel behavioural paradigm might prove effective in dissociating the neural bases of preparatory and mnestic processes in normal human subjects, as well as their disorders in neurological patients.     

小儿左心辅助心电触发方式下辅助延迟时间的探讨

心电是触发左心辅助同步控制的一个重要的信号源 ,而辅助延迟时间是辅助循环中的一个重要环节。适当的延迟既可以使左心辅助装置 (L VAD)有充分的收缩时间 ,又可以避免 L VAD与心脏在收缩期的冲突 ;如果延迟时间不适当、尤其是在左心房引流不充分时 ,L VAD与心脏的冲突在短时间内就可造成急性左心衰、肺水肿。本文旨在寻找一个经验公式以有效地指导 L VAD延迟时间。目的 :以 R- Ao代表心电 QRS波峰点与主动脉瓣关闭结束的间隔时间 ,以 RR代表 RR间期 ,找出 RR与 R- Ao的相关方程 :R- Ao=A× (RR) n+B。通过加权平均法计算RR的平均值 ,再求出 R- Ao预期值 ,对 R- Ao做安全较正后 ,以此做为辅助的延迟时间。方法 :选择 5～ 14岁行升主动脉导管的小儿患者 ,经筛选 ,测量 45 7例心导管记录图中心电部分的 RR间期以及与此心电对应的主动脉压力波形 ,测量主动脉下降波切迹与 QRS波起始点间的间隔 ,以 R- Ao为因变量 ,以 (RR) n为自变量 ,绘散点图 ,找出相关模型 ,并求出相关方程。结论 :当心率小于 12 0次 / min时 ,相关系数为 0 .733,回归系数为 - 0 .182 ,P值为 2 .2 94E-78;截距为 1.0 70 ,P值为 4.83E- 10 9,相关方程为 :R- Ao=(- 0 .182 ) RR1 /3 +1.0 70。     

Single unit activity during a Go/NoGo task in the “prefrontal cortex” of pigeons

Single unit activity was recorded during a delayed auditory/visual Go/NoGo task from the neostriatum caudolaterale (NCL) of pigeons, a multimodal associative avian forebrain structure comparable to the prefrontal cortex (PFC). The animals were trained to mandibulate (to open their beak) during the Go period after which they received a drop of water as reward. Neuronal activity changes were observed during the delay period (DELAY) between auditory and visual stimulation, to the onset of the visual stimulus or to the delivery of the reward. In some neurons, responses were related to the behavioral significance of the stimulus such that the neuronal activity was statistically different between Go and NoGo trials. Moreover, some units anticipated the upcoming reward or changed their firing frequency in a correlated manner prior to beak movements. These neuronal activity patterns suggest that the NCL provides a neural network that participates in the integration and processing of external stimuli in order to generate goal directed behavior.     

改水降氟对小学生骨龄发育的影响

目的 研究氟中毒病区青少年在长期改饮低氟水后的骨骼发育的恢复情况。方法 用横断面调查方法选取已经改水２３年的原地方性氟中毒重病区为研究点,并设未改水重病区为病区对照,非病区为正常对照的８～１３岁小学生,用李果珍法观察骨龄状况,以Ｄｅａｎ法判定氟斑牙速度。结果 改水成功的原地方性氟中毒得病区的青少年饮用低氟水后,影响其体格发育的重要指标骨龄延迟率有明显的下降,已经接近非病区的水平。结论 改饮低氟水将     

A波延迟电位在慢径消融靶点定位中的应用

为了探讨A波延迟电位在慢径消融靶点定位中的应用价值 ,对传统下位法和A波延迟电位引导下的慢径消融两组病例的靶点的电生理特征进行了研究。结果 :延迟电位引导下的慢径消融在提高成功率、减少试放电方面明显优于下位法。有效靶点的突出特征是A波宽度 >6 8ms、A波终末具延迟电位 ,A/V比例不能作为预测靶点的指标。A波延迟电位有四种形态 ,分别为单弓状延迟电位、双弓状延迟电位、穗状电位及A波终末的高频电位 ,其中以前两种最为常见。当程序刺激遇快径不应期而经慢径传导时 ,靶点正传的A波更加延迟 ,逆传A波更加领先是成功靶点的特征。结论 :在慢径消融的靶点定位中应用A波延迟电位和程序刺激可提高成功率、减少盲目性 ,A波延迟电位引导慢径消融方法优于传统的消融方法慢径消融方法优于传统的消融方法     

Delays in the diagnosis and treatment of tuberculosis during the COVID-19 outbreak in the Republic of Korea in 2020

ObjectivesWe investigated the impact of the coronavirus disease 2019 (COVID-19) pandemic on tuberculosis (TB) "diagnosis and" management in the Republic of Korea (ROK).Methods This retrospective cross-sectional study used nationwide ROK TB notification data (98,346 cases) from 2017 to 2020. The median time from the onset of TB symptoms to treatment initiation and the compliance rates with the required timing for notification and individual case investigations were measured and compared across periods and regions affected by the COVID-19 epidemic.Results TB diagnosis during the COVID-19 pandemic was delayed. The median time to TB treatment initiation (25 days) in 2020 increased by 3 days compared to that of the previous 3 years (22 days) (p<0.0001). In the outbreak in Seoul, Incheon, and Gyeonggi province during August, the time to TB diagnosis was 4 days longer than in the previous 3 years (p=0.0303). In the outbreak in Daegu and Gyeongbuk province from February to March 2020, the compliance rate with the required timing for individual case investigations was 2.2%p lower than in other areas in 2020 (p=0.0148). For public health centers, the rate was 13%p lower than in other areas (80.3% vs. 93.3%, p=0.0003).Conclusion TB diagnoses during the COVID-19 pandemic in the ROK were delayed nationwide, especially for patients notified by public-private mix TB control hospitals. TB individual case investigations were delayed in regional COVID-19 outbreak areas (Daegu and Gyeongbuk province), especially in public health centers. Developing strategies to address this issue will be helpful for sustainable TB management during future outbreaks.