[Characteristics of vocalization in children with autism spectrum disorder during the still-face paradigm]

OBJECTIVE

To study the characteristics of vocalization during the still-face paradigm (SFP) before the age of 2 years and their correlation with the severity of autism spectrum disorder (ASD) symptoms at diagnosis in children with ASD.

METHODS

A total of 43 children aged 7-23 months, who were suspected of ASD, were enrolled as the suspected ASD group, and 37 typical development (TD) children, aged 7-23 months, were enrolled as the TD group. The frequency and durations of vocalization in the SFP were measured. The children in the suspected ASD group were followed up to the age of 2 years, and 34 children were diagnosed with ASD. Autism Diagnostic Observation Schedule (ADOS) was used to assess the severity of symptoms. The correlation of the characteristics of vocalization before the age of 2 years with the severity of ASD symptoms was analyzed.

RESULTS

Compared with the TD group, the ASD group had significant reductions in the frequency and durations of meaningful vocalization and vocalization towards people and a significant increase in the duration of vocalization toward objects (P<0.05). The Spearman correlation analysis showed that in the ASD group, the frequency and durations of total vocalization, non-speech vocalization, babbling, vocalization towards people, and vocalization towards objects were negatively correlated with the score of communication in ADOS (P<0.05). The frequency and durations of total vocalization, babbling, and vocalization towards people and the duration of vocalization towards objects were negatively correlated with the score of reciprocal social interaction in ADOS (P<0.05). The frequency of total vocalization, the duration of babbling, and the frequency and duration of vocalization towards people were negatively correlated with the score of play in ADOS (P<0.05). The frequency of total vocalization and non-speech vocalization and the frequency and durations of vocalization towards people were negatively correlated with the score of stereotyped behaviors and restricted interests in ADOS (P<0.05). The multiple linear regression analysis showed that the frequency of total vocalization was a negative predictive factor for the score of communication in ADOS (P<0.001), and the duration of vocalization towards people was a negative predictive factor for the score of reciprocal social interaction in ADOS (P<0.05).

CONCLUSIONS

SFP can better highlight the abnormal vocalization of ASD children before the age of 2 years, and such abnormalities can predict the severity of ASD symptoms early.

Identification of aac(2')-I type b aminoglycoside-modifying enzyme genes in resistant Acinetobacter baumannii

The aim of this study was to investigate the mechanism underlying the drug resistance of Acinetobacter baumannii toward aminoglycosides. A total of 32 A. baumannii strains were identified by molecular identification and subsequently isolated. The isolates were then amplified by polymerase chain reaction to analyze the 9 aminoglycoside-modifying enzyme genes and 7 16S rRNA methylase genes. Five types of aminoglycoside-modifying enzyme genes and 1 type of 16S rRNA methylase gene were detected in the 32 drug-resistant A. baumannii strains. Positive genes included 7 detection modes, of which the all-6-gene-positive mode aac(2')-Ib+aac(3)-I+aac(6')-Ib+ant(3'')-I+aph(3')-I+armA exhibited the largest number of strains (12, 37.5%). The resistance of A. baumannii against aminoglycosides resulted from the presence of 5 types of aminoglycoside-modifying enzyme genes and the 16S rRNA methylase gene armA. This study is the first to isolate the aac(2')-Ib aminoglycoside-modifying enzyme gene from A. baumannii in a domestic clinical setting.

Anomalous-circular photogalvanic effect in a GaAs/AlGaAs two-dimensional electron gas

We have studied the circular photogalvanic effect (CPGE) in a GaAs/AlGaAs two-dimensional electron gas excited by near infrared light at room temperature. The anomalous CPGE observed under normal incidence indicates a swirling current which is realized by a radial spin current via the reciprocal spin-Hall effect. The anomalous CPGE exhibits a cubic cosine dependence on the incidence angle, which is discussed in line with the above interpretation.

Anomalous photogalvanic effect of circularly polarized light incident on the two-dimensional electron gas in Al{x}Ga{1-x}N/GaN heterostructures at room temperature

Under normal incidence of circularly polarized light at room temperature, a charge current with swirly distribution has been observed in the two-dimensional electron gas in Al{0.25}Ga{0.75}N/GaN heterostructures. We believe that this anomalous charge current is produced by a radial spin current via the reciprocal spin Hall effect. It suggests a new way to research the reciprocal spin Hall effect and spin current on the macroscopic scale and at room temperature.

Early pathomorphologic characteristics of the wound track caused by fragments

Soft-tissue wounds were inflicted on the upper parts of both hind legs of dogs by fragments which were shot with a smooth-bore testing rifle. Three impact velocities were used: "high" (1,500 m/s, six dogs), "middle" (1,000 m/s, eight dogs) and "low" (700 m/s, seven dogs). Debridement and gross examination were carried out 6 hours after wounding. The main conclusions were as follows: 1) Grossly, most of the wound tracks were blind. The primary wound track in the "high"-velocity group looked like a funnel in shape. The wound cavity close to the entrance had the largest diameter. 2) The severity of the tissue damage depended on the impact velocity. The higher the velocity, the larger were the wound cavities, the more tissues damaged, and the wider was the area of tissue damage around the cavity. 3) Based on the gross, light microscopy (LM), and electron microscopy (EM) observations it was found that one of the predominant characteristics of the tissue damage caused by fragments was the irregularity or unevenness. This was especially true in the case of the "high"-velocity group. The distribution of tissue damage seemed to be "jumping" or "mosaic." This probably resulted from the irregularity of the energy delivery from fragments with high velocity and low mass. 4) The differences in morphologic characteristics between wound tracks caused by bullets and those by fragments are discussed.