Semantic integration processes at different levels of syntactic hierarchy during sentence comprehension: An ERP study

An event-related potential (ERP) study was conducted to investigate the temporal neural dynamics of semantic integration processes at different levels of syntactic hierarchy during Chinese sentence reading. In a hierarchical structure, subject noun + verb + numeral + classifier + object noun, the object noun is constrained by selectional restrictions of the classifier at the lower-level and of the verb at the higher-level and the classifier is also constrained by the verb at the higher-level. Semantic congruencies between verb, classifier, and noun were manipulated, resulting in five types of sentences: correct sentences, sentences with the single classifier-noun mismatch, sentences with the single verb-noun mismatch, sentences with the double-mismatch in classifier-noun and verb-noun, and sentences with the triple-mismatch in classifier-noun, verb-noun and verb-classifier. Compared with correct sentences, all four types of mismatches elicited N400 effects on the noun, with the effect in the double-mismatch equal to the effect in the single classifier-noun mismatch but larger than the effect in the single verb-noun mismatch. In addition, the single verb-noun mismatch and the double-mismatch elicited a left-posterior positivity effect and an anterior negativity effect in the 550-800 ms time window on the noun, with the effects larger in the double-mismatch than in the single-mismatch. The classifier-noun mismatch also elicited the late anterior negativity effect on the noun. Although the triple-mismatch did not induce a significant late positivity effect on the noun, it did on the classifier. The pattern of the N400 effects suggests that semantic processes at different levels of syntactic hierarchy interact in integrating the incoming word into the prior sentence context with neither process overriding the other. The late-posterior positivity effect may reflect the coordination of various semantic integration processes across hierarchical levels during sentence comprehension.     

Contact allergy to furazolidone

A case of occupational contact allergy to furazolidone, used as an animal feed additive and as an antimicrobial drug in veterinary medicine, is described. The patient did not react to furazolidone 2% pet. Using PEG-400 and alcohol as patch test vehicles resulted in positive patch test reactions. No cross-reactions were observed to other nitrofuran derivatives (nitrofurazone, nitrofurantoin) or to furfural. The literature on contact allergy to nitrofurans is reviewed.     

From print to meaning: an electrophysiological investigation of the role of phonology in accessing word meaning.

This study investigated the role and time-course of phonology in accessing meaning during silent reading. In Experiment 1, the homophone effect was replicated in a semantic categorization task in French. When deciding whether a stimulus belonged to a semantic category (FOOD), subjects made more errors to homophones (MEET) than to orthographic controls (MELT). In Experiment 2, event-related brain potentials (ERPs) were used to study the online development of this effect. If access to meaning was mediated by phonology, smaller N400 components should be obtained to homophones than to orthographic controls. The ERP data exhibited a full-blown N400 component to homophones that did not differ from the N400 to controls. No differences between homophones and controls were found before the N400. After the N400, however, homophones differed from controls, with ERPs to homophones being similar to those of correct category exemplars. The results suggest that the final selection of a word's meaning does not depend on its phonological form. This result is incompatible with a strong phonological view according to which the only way to meaning is via a word's phonology.     

酰胺酰亚胺和内酰胺的相转移催化N—烃化反应

利用PEG-400和氢氧化钾或碳酸钾,在固-液相转移催化条件下进行酰胺酰亚胺和内酰胺的N-烃化反应,N-烃基物的收率较高。     

Neonatal screening for hyperlipoproteinemia. Methods for direct estimation of cord serum VLDL + LDL.

The early detection of hyperlipoproteinemia in newborn infants has so far been based upon estimation of cord blood total lipids (cholesterol and triglyceride) and lipoprotein-lipids (VLDL-, LDL- and HDL-cholesterol). To be able to make a direct estimation of cord serum beta-lipoproteins (VLDL + LDL) two quite different methods were modified, one immunological and the other turbidimetric. Good correlations were found to VLDL- + LDL-cholesterol isolated in the ultracentrifuge (r = 0.848 and 0.831, respectively). If neonatal screening for hyperlipoproteinemia is considered, we recommend the very easy and inexpensive turbidimetric method. Furthermore, using cord serum, two conventional precipitation methods with heparin-CaCl2 and heparin-MnCl2 were compared by ultracentrifugation and high correlations were found (r = 0.923 and 0.899, respectively). A clamping study showed that following early clamping of the cord, the concentration of cord serum lipids and lipoproteins did not change markedly within the first five minutes. Storing experiments showed that serum should be separated within the first 12 h to avoid unpredictable changes in the concentration of cord serum lipids and lipoproteins.     

Effect of Low-Dose Vs Standard-Dose Valganciclovir in the Prevention of Cytomegalovirus Disease in Kidney Transplantation Recipients: A Systemic Review and Meta-Analysis

Background

Valganciclovir is widely used to prevent post-transplant cytomegalovirus (CMV) infection in kidney transplant patients. However, the currently used dose remains controversial because the continuous use of this drug decreases kidney function and can induce leukopenia.