人工肝支持系统治疗肝衰竭的研究进展

目前肝衰竭发病率和病死率仍然较高,肝衰竭成为威胁患者生命的严重疾病。基于肝脏具有强大再生能力,人工肝支持系统作为一种“过渡”措施,为肝衰竭患者的肝功能恢复赢得时间。人工肝支持系统根据性质不同分为非生物型人工肝、生物型人工肝和混合型人工肝。目前非生物型人工肝已在肝病治疗领域被广泛应用,但生物型及混合型人工肝的临床应用还存在很多问题需要进一步研究和解决。因此本文对人工肝的作用、临床应用现状、存在问题及研究进展进行综述。     

释《周易·渐卦》

通过对渐卦卦象的分析,并考《说文》段注“陂陀曰渐”,得出渐卦取名为渐,当取坡渐之意,进而引伸为渐进之意。又从卦爻象出发,对渐卦的卦爻辞作出分析,认为渐卦的卦爻辞是根据其卦爻象而系出,而且其整卦的卦爻辞都是围绕着一个中心主题而展开,且其思想与《诗经》中的《鸿雁》等篇不无关系。这或可为进一步解读《周易》古经及其产生时代问题提供某种有益的启示。     

Reclaiming “Natural Partnership and Communication”

The massive scale of forced displacement across the globe discloses the fractured state of the modern international order. Francisco de Vitoria’s theological approach to the law of nations, in the context of the Spanish conquest of the Americas, had a significant influence on this order’s development. This paper argues that recovering his innovative insights today can help refurbish a collective sense of international responsibility for refugees. Vitoria’s bold assertion of indigenous Americans’ dominion affirmed all human beings as members of a world commonwealth with equal claims to basic rights. The “right to travel” he articulated, by its orientation to “natural partnership and communication,” can promote refugee rights and global fraternity.     

Resistance to extinction versus extinction as discrimination

The hypothesis that response strength might be measured by persistence of responding in the face of extinction was discredited in the 1960s because experiments showed that responding persists longer following intermittent reinforcers than following continuous reinforcers. Instead, researchers proposed that the longer persistence following intermittent reinforcers arises because intermittent reinforcement more closely resembles extinction—a discrimination theory. Attention to resistance to extinction revived because one observation seemed to support the persistence hypothesis: Following training on a multiple schedule with unequal components, responding usually persisted longer in the formerly richer component than in the formerly lean component. This observation represents an anomaly, however, because results with single schedules and concurrent schedules contradict it. We suggest that the difference in results arises because the multiple-schedule procedure, while including extensive training on stimulus discrimination, includes no training on discrimination between food available and food unavailable, whereas comparable single- and concurrent-schedule procedures include such training with repeated extinction. In Experiment 1, we replicated the original result, and in Experiment 2 showed that when the multiple-schedule procedure includes training on food/no-food discrimination, extinction following multiple schedules contradicts behavioral momentum theory and agrees with the discrimination theory and research with single and concurrent schedules.     

Behavioral ephemera,difficult discriminations,and behavioral stability

Every species possesses abilities for successfully interacting with its environment. These result from phylogeny. In the laboratory, one may arrange artificial conditions that thwart an organism's abilities. The result may be a “phenomenon.” With sufficient training, however, the phenomenon may prove to be ephemeral, as the organism's basic abilities reassert themselves. Pigeons respond extremely well to differences and nondifferences in rate of obtaining food. This ability may be thwarted in a variety of ways, but the results tend to be ephemeral. An example is an experiment that pitted pigeons' preference for unimpeded responding against their ability to respond to food rate. In a concurrent-chains procedure, the terminal links were identical variable-interval schedules, but in one terminal link, every response produced a timeout. The duration of the timeout varied, and preference varied with it, but the relation vanished with training, in keeping with the equality of food rate across the 2 terminal links. Some other examples of “phenomena” that tend to disappear with sufficient training and sufficient variation in experimental parameters are behavioral contrast, conditioned reinforcement, resistance to extinction, and suboptimal choice. These “phenomena” depend on pigeons' failing to make difficult discriminations. They appear to be behavioral ephemera.     

Young children's understanding of displaced aggression

According to previous research, young children do not understand displaced aggression. The present study examines the early phases of the understanding of the causes of moderately and extremely displaced aggression. Preschool and kindergarten children (3 to 5 years of age) viewed eight videotaped episodes of displaced aggression. Their comprehension of this aggression was assessed by means of open ended questions and forced choice picture selections. By age 5 most children had some understanding of displaced aggression, but this understanding was not complete. The early understanding revealed in the present study may be due to the use of short, simple realistic videotaped episodes appropriate for the limited processing abilities of young children. Extreme displacement was not more difficult to understand than moderate displacement.     

Jumping to conclusions in the less-delusion-prone? Further evidence from a more reliable beads task

BackgroundA single meta-analysis has found that healthy people with higher delusion-proneness tend to gather less information (i.e., make fewer draws to decision, or DTD) on the beads task, although the findings of contributing studies were mixed, and the pooled effect size was small. However, using a new and more reliable “distractor sequences” beads task, we recently found a positive relationship between delusion-proneness and DTD in a healthy sample. In the current study, we re-tested this relationship in a new sample, and tested the possibility that the relationship is driven by participant’s ability to understand and use odds or likelihood information (“odds literacy”).MethodsHealthy participants (N = 167) completed the distractor sequences beads task, the Peters Delusions Inventory (PDI) which measures delusion-proneness, a measure of odds literacy, and the Depression, Anxiety, and Stress scale.ResultsPDI and DTD were positively correlated, and comparing PDI quartiles on DTD confirmed a statistically significant trend of increasing DTD with PDI quartile. Odds literacy was positively rather than negatively associated with both DTD and PDI. Anxiety was positively correlated with PDI and DTD.ConclusionsWe replicated our earlier finding that DTD and delusion-proneness were positively related in a non-clinical sample, but found that increased odds-literacy did not drive lower PDI and DTD, and hence did not explain their covariance. It is possible however that anxiety and co-occurring risk aversion drive increased delusion-proneness and information-gathering, potentially accounting for the positive relationship between PDI and DTD.     

Assessing potential reinforcement-like effects of brief stimuli unrelated to food reinforcers

It is widely assumed that reinforcers are biologically relevant stimuli, or stimuli that have been associated with biologically relevant stimuli. However, brief, arbitrary stimuli have also been reported to have reinforcement-like effects, despite being unrelated to biologically relevant stimuli like food. The present study explored the potential reinforcement-like effects of brief stimuli across 5 experiments. In Experiments 1 through 4, pigeon subjects responded for food reinforcement and brief stimulus presentations in a 2-component multiple schedule. Neither baseline response rates nor resistance to change during disruption tests were systematically greater in a component with versus without brief stimulus presentations. Increasing the rate and duration of brief stimulus presentations in Experiment 4 did not reveal reinforcement-like effects when compared directly with food. In Experiment 5, pigeons chose between independent terminal links in a concurrent-chains procedure. Across conditions, varying the location, duration, and rate of brief stimulus presentations in the terminal links had no systematic effects on preference. In contrast, varying rates of food reinforcers resulted in large and reliable shifts in preference. Therefore, the present study found no systematic evidence that brief stimuli unrelated to food reliably increase response rates, resistance to change, or preference. These data demonstrate the value of systematic replication, and a behavioral momentum approach to assessing potential reinforcement-like effects.