The underlying neuropsychological and neural correlates of the impaired Chinese reading skills in children with attention deficit hyperactivity disorder.

Impaired basic academic skills (e.g., word recognition) are common in children with Attention Deficit Hyperactivity Disorder (ADHD). The underlying neuropsychological and neural correlates of impaired Chinese reading skills in children with ADHD have not been substantially explored. Three hundred and two children with ADHD (all medication-naïve) and 105 healthy controls underwent the Chinese language skill assessment, and 175 also underwent fMRI scans (84 ADHD and 91 controls). Between-group and mediation analyses were applied to explore the interrelationships of the diagnosis of ADHD, cognitive dysfunction, and impaired reading skills. Five ADHD-related brain functional networks, including the default mode network (DMN) and the dorsal attention network (DAN), were built using predefined regions of interest. Voxel-based group-wise comparisons were performed. The ADHD group performed worse than the control group in word-level reading ability tests, with lower scores in Chinese character recognition (CR) and word chains (WS) (all P < 0.05). With full-scale IQ and sustained attention in the mediation model, the direct effect of ADHD status on the CR score became insignificant (P = 0.066). The underlying neural correlates for the orthographic knowledge (OT) and CR differed between the ADHD and the control group. The ADHD group tended to recruit more DMN regions to maintain their reading performance, while the control group seemed to utilize more DAN regions. Children with ADHD generally presented impaired word-level reading skills, which might be caused by impaired sustained attention and lower IQ. According to the brain functional results, we infer that ADHD children might utilize a different strategy to maintain their orthographic knowledge and character recognition performance.

Aperiodic components and aperiodic-adjusted alpha-band oscillations in children with ADHD.

This study aimed to investigate the aperiodic properties and aperiodic-adjusted alpha-band oscillations in children with ADHD, focusing on the influence of different scalp regions and lateralization on these neural correlates. Sixty-two ADHD children and 52 typical developing children aged 6-12 years were enrolled. EEG recordings were made with eyes closed for a minimum of 6 min. The 'FOOOF' was used to compute aperiodic parameters (exponent and offset), and aperiodic-adjusted alpha-band features including center frequency (CF), adjusted power (AP), and bandwidth (BW). Mixed-design ANOVAs were conducted with two between-subjects levels (ADHD and control groups) and two within-subjects' factors (lateralization and scalp region). ANCOVAs were conducted after accounting for sex and age. The ADHD group showed a significantly lower exponent compared to the control group, and this difference was not influenced significantly by factors like lateralization, scalp region, or sex. There were no notable distinctions between the groups for other measures. We noticed alpha-band CF tends to increase with age, while only frontal AP shows a significant positive correlation with age. Significant main effects of sex and lateralization were observed for offset, along with an interaction effect between sex and lateralization for CF. Our findings indicate that children aged 6-12 with ADHD have a markedly lower exponent, suggesting that this measure could potentially serve as a biomarker for ADHD. Future studies should consider factors such as age, sex, lateralization, and scalp region when investigating aperiodic and aperiodic-adjusted features.

Bioactivity of umbilical cord blood dendritic cells and anti-leukemia effect.

OBJECTIVE: We investigated the effect of umbilical cord blood dendritic cells (DCs) on in vitro proliferation, immunophenotypes and levels of homologous cytokine-induced killer cells (CIK) and the toxicity on leukemia cells. METHOD: Mononuclear cell-induced DC-CIK cells derived from umbilical cord blood were collected and co-cultured in the proportion of 1:5. Cord blood CIK cells or peripheral blood DC-CIK cells were used as control. Phenotypes were analyzed by flow cytometry; vial cell counting was performed using trypan blue, and the killing activity of effector cells against leukemia cells was measured by MTT assay. The levels of interferon-r (IFN-r), tumor necrosis factor-a (TNF-α) and interleukin-12 (IL-12) were determined by ELISA. RESULTS: The proliferative capacity of DC-CIK cells was obviously improved compared with cord blood CIK cells and peripheral blood DC-CIK cells (P<0.05, P<0.05). During the co-culture of cord blood DC-CIK cells, the ratios of CD 3 (+) CD 8 (+) and CD 3 (+) CD 56 (+) cells were obviously higher than that of CIK cells under the same conditions (P<0.05). On day 3 of co-culture, the levels of IL-12, IFN-r and TNF-a in cultured supernatant of cord blood DC-CIK cells were all higher than those secreted by CIK cells cultured alone (P<0.01, P<0.05, P<0.05). When the effector to target ratio was 2.5-20:1, the killing effect of cord blood DC-CIK cells against each subtype of acute leukemia cells was obviously higher than that of CIK cells (P<0.05). No significant differences in killing effect were observed for different subtypes. This finding was consistent with the killing effect of peripheral blood DC-CIK cells against leukemia cells. CONCLUSION: Cord blood DCs can enhance the proliferative capacity of homologous CIK cells and its anti-leukemia effect. Though cord blood DC-CIK cells showed a higher proliferative capacity than peripheral blood DC-CIK cells, the two types of DC-CIK cells did not differ significantly in terms of cytoxicity. With a high availability and the low probability of graft rejection reaction, cord blood DC-CIK cells have a brighter prospect for application in immunotherapy.

Visible light catalysis-assisted assembly of Ni(h)-QD hollow nanospheres in situ via hydrogen bubbles.

Hollow spheres are one of the most promising micro-/nanostructures because of their unique performance in diverse applications. Templates, surfactants, and structure-directing agents are often used to control the sizes and morphologies of hollow spheres. In this Article, we describe a simple method based on visible light catalysis for preparing hollow nanospheres from CdE (E = Te, Se, and S) quantum dots (QDs) and nickel (Ni(2+)) salts in aqueous media. In contrast to the well-developed traditional approaches, the hollow nanospheres of QDs are formed in situ by the photogeneration of hydrogen (H2) gas bubbles at room temperature. Each component, that is, the QDs, metal ions, ascorbic acid (H2A), and visible light, is essential for the formation of hollow nanospheres. The quality of the hollow nanospheres depends on the pH, metal ions, and wavelength and intensity of visible light used. Of the various metal ions investigated, including Cu(+), Cu(2+), Fe(2+), Fe(3+), Ni(2+), Mn(2+), RuCl5(2-), Ag(+), and PtCl4(2-), Ni(2+) ions showed the best ability to generate H2 and hollow-structured nanospheres under visible light irradiation. The average diameter and shell thickness of the nanospheres ranged from 10 to 20 nm and from 3 to 6 nm, respectively, which are values rarely reported in the literature. Studies using high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), inductively coupled plasma-mass spectroscopy (ICP-AES), and steady-state and time-resolved spectroscopy revealed the chemical nature of the hollow nanospheres. Additionally, the hollow-structured nanospheres exhibit excellent photocatalytic activity and stability for the generation of H2 with a rate constant of 21 µmol h(-1) mg(-1) and a turnover number (TON) of 137,500 or 30,250 for CdTe QDs or nickel, respectively, under visible light irradiation for 42 h.

Photocatalytic hydrogen evolution from glycerol and water over nickel-hybrid cadmium sulfide quantum dots under visible-light irradiation.

Natural photosynthesis offers the concept of storing sunlight in chemical form as hydrogen (H2), using biomass and water. Herein we describe a robust artificial photocatalyst, nickel-hybrid CdS quantum dots (Nih-CdS QDs) made in situ from nickel salts and CdS QDs stabilized by 3-mercaptopropionic acid, for visible-light-driven H2 evolution from glycerol and water. With visible light irradiation for 20 h, 403.2 µmol of H2 was obtained with a high H2 evolution rate of approximately 74.6 µmol h(-1) mg(-1) and a high turnover number of 38 405 compared to MPA-CdS QDs (mercaptopropionic-acid-stabilized CdS quantum dots). Compared to CdTe QDs and CdSe QDs, the modified CdS QDs show the greatest affinity toward Ni(2+) ions and the highest activity for H2 evolution. X-ray photoelectron spectroscopy (XPS), inductively-coupled plasma atomic emission spectrometry (ICP-AES), and photophysical studies reveal the chemical nature of the Nih-CdS QDs. Electron paramagnetic resonance (EPR) and terephthalate fluorescence measurements clearly demonstrate water splitting to generate ⋅OH radicals. The detection of DMPO-H and DMPO-C radicals adduct in EPR also indicate that ⋅H radicals and ⋅C radicals are the active species in the catalytic cycle.

An exceptional artificial photocatalyst, Nih -CdSe/CdS core/shell hybrid, made in situ from CdSe quantum dots and nickel salts for efficient hydrogen evolution.

A novel hybrid Nih -CdSe/CdS core/shell quantum dot is a simple and exceptional artificial photocatalyst for H2 production from 2-propanol aqueous solution. Studies on the nature of the artificial photocatalyst and mechanism for H2 production demonstrate that the synthetic strategy is general and the artificial photocatalyst holds promise for light capture, electron transfer, and catalysis at the surface of the Nih -CdSe/CdS core/shell quantum dots, leading to a self-healing system for H2 evolution in harmony.

Reversible sol-to-gel transformation of uracil gelators: specific colorimetric and fluorimetric sensor for fluoride ions.

A new type of anthracene organogelator based on uracil was obtained using organic aromatic solvents, cyclohexane, DMSO, ethanol, and ethyl acetate. It was further characterized by field-emission scanning electron microscopy and transmission electron microscopy. Specifically, the resulting organogels were demonstrated to be promising colorimetric and fluorescent sensors toward fluoride ions with high sensitivity and selectivity, accompanying the disruption of the gelators. Spectroscopic study and (1)H NMR titration experiment revealed that the deprotonation of the hydrogen atom on the N position of uracil moiety by fluoride ions is responsible for the recognition events, evidenced by immediate transformation from the sol phase to the gel state upon adding a small amount of a proton solvent, methanol. The process is reversible, with zero loss in sensing activity and sol-to-gel transformation ability even after five runs.

Neural basis of phonological processing in second language reading: an fMRI study of Chinese regularity effect.

The present study examined the neural basis of phonological processing in Chinese later acquired as a second language (L2). The regularity effect of Chinese was selected to elucidate the addressed phonological processing. We recruited a group of alphabetic language speakers who had been learning Chinese as L2 for at least one year, and a control group of native Chinese speakers. Participants from both groups exhibited a regularity effect in a pilot behavioral test. Neuroimaging results revealed that L2 learners exhibited stronger activation than native Chinese speakers in the right occipitotemporal region (i.e. right lingual gyrus and right fusiform gyrus). Moreover, L2 learners exhibited greater activations in the ventral aspects of the left inferior parietal lobule (LIPL) and the left inferior frontal gyrus (LIFG) for irregular character reading minus regular character reading. In contrast, native Chinese speakers exhibited more dorsal activations in the LIPL and LIFG. According to the "accommodation/assimilation" hypothesis of second language reading, the current findings suggest that native speakers of alphabetic languages utilized an accommodation pattern for the specific requirements of the visual form of Chinese characters, and an assimilation pattern for orthography-to-phonology transformation in Chinese reading.

The visual magnocellular pathway in Chinese-speaking children with developmental dyslexia.

Previous research into the cognitive processes involved in reading Chinese and developmental dyslexia in Chinese, revealed that the single most important factor appears to be orthographic processing skills rather than phonological skills. Also some studies have indicated that even in alphabetic languages some dyslexic individuals reveal deficits in orthographic processing skills, which are linked to a deficit in the visual magnocellular pathway. The current study therefore employed a visual psychophysical experiment together with visual and auditory event-related potential (ERP) experiments eliciting mismatch negativity (MMN) to investigate the link between visual magnocellular functional abnormalities and developmental dyslexia in Chinese. The performance levels of Chinese children with developmental dyslexia (DD) from the behavioural and electrophysiological experiments were compared to those of the chronological age-matched (CA) children and those of the reading level matched (RL) younger children. Both the behavioural and electrophysiological results suggest that the orthographic processing skills were compromised in the Chinese developmental dyslexics, which in turn is linked to a deficit in the visual magnocellular system.