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Xiaosong Li

Publications and source records attributed to Xiaosong Li.

14 recordsLinked to original sources
PubMed2026

Transcranial Alternating Current Stimulation at 40 Hz Improves Social Functioning in Children With Autism Spectrum Disorder: A Randomized Clinical Trial.

BACKGROUND: Autism spectrum disorder (ASD) lacks rapid and effective interventions for its core social difficulties. The right temporoparietal junction (rTPJ), a critical hub for social cognition, together with gamma band abnormalities implicated in ASD, provides a promising neuromodulation target. METHODS: In this randomized, double-blind, sham-controlled trial, 47 children with ASD (39 male; mean [SD] age = 8.79 [2.71] years) were assigned to receive either 21 sessions of 40-Hz high-definition transcranial alternating current stimulation (tACS) targeting the rTPJ (3 sessions/day for 7 days) or sham stimulation, with assessments conducted at baseline, postintervention (week 1), and a 3-week follow-up (week 4). The primary outcome was change in Ohio State University Autism Rating Scale-DSM-5 (OARS-5) total scores. Secondary outcomes included the Aberrant Behavior Checklist-Second Edition, Social Responsiveness Scale-Second Edition, and Short Sensory Profile. Eye-tracking metrics during Frith-Happ&#xe9; animations were exploratory measures of theory of mind (ToM)-related social cognitive processing. RESULTS: The active group demonstrated significant improvements in OARS-5 total scores at week 1 (mean difference = -1.13, 95% CI [-1.78 to -0.47], p < .001) and week 4 (mean difference = -1.47, 95% CI [-2.20 to -0.74], p < .001). Improvements in selected behavioral and sensory domains were observed. Average fixation duration during ToM animations showed a significant group &#xd7; time interaction. No serious adverse events occurred. CONCLUSIONS: These findings suggest that 40-Hz tACS targeting the rTPJ may be associated with rapid improvements in ASD symptom severity, particularly social functioning, in children with ASD, while being well tolerated. Clinical significance requires further evaluation.

Humans↗
PubMed2006

Allele frequencies of 15 STR loci of Tibetan lived in Tibet Lassa.

Allele frequency data for 15 Short Tandem Repeat (STR) loci included in the AmpFl STR Identifiler kit were obtained from a sample of 196 healthy unrelated individuals of Tibetan born in Lassa of Tibet Autonomy Region of China (SW China). The distribution of these observed genotypes were not significantly different from the expected distribution according to Hardy-Weinberg equilibrium.

Asian People↗
PubMed2005

Numerical simulation of nonadiabatic electron excitation in the strong field regime. 2. Linear polyene cations.

Time-dependent Hartree-Fock theory has been used to study the electronic optical response of a series of linear polyene cations (+1 and +2) in strong laser fields. The interaction of ethylene, butadiene, and hexatriene, with pulsed and CW fields corresponding to 8.75 x 10(13) W/cm(2) and 760 nm, have been calculated using the 6-31G(d,p) basis set. Nonadiabatic processes including nonlinear response of the dipole moment to the field and non-resonant energy deposition into excited states were more pronounced for the monocations in comparison with dications. For a given charge state and geometry, the nonadiabatic effects in the charge distribution and instantaneous dipole increased with the length of the polyene. For pulsed fields, the instantaneous dipole continued to oscillate after the field returned to zero and corresponded to a non-resonant electronic excitation involving primarily the lowest electronic transition. For a given molecule and fixed charge state, the degree of nonadiabatic coupling and excitation was greater for geometries with lower excitation energies.

Journal Article↗
PubMed2005

Ab initio Ehrenfest dynamics.

We present an ab initio direct Ehrenfest dynamics scheme using a three time-step integrator. The three different time steps are implemented with nuclear velocity Verlet, nuclear-position-coupled midpoint Fock integrator, and time-dependent Hartree-Fock with a modified midpoint and unitary transformation algorithm. The computational cost of the ab initio direct Ehrenfest dynamics presented here is found to be only a factor of 2-4 larger than that of Born-Oppenheimer (BO) dynamics. As an example, we compute the vibration of the NaCl molecule and the intramolecular torsional motion of H2C=NH2+ by Ehrenfest dynamics compared with BO dynamics. For the vibration of NaCl with an initial kinetic energy of 1.16 eV, Ehrenfest dynamics converges to BO dynamics with the same vibrational frequency. The intramolecular rotation of H2C=NH2+ produces significant electronic excitation in the Ehrenfest trajectory. The amount of nonadiabaticity, suggested by the amplitude of the coherent progression of the excited and ground electronic states, is observed to be directly related to the strength of the electron-nuclear coupling. Such nonadiabaticity is seen to have a significant effect on the dynamics compared with the adiabatic approximation.

Journal Article↗
PubMed2005

A numerical simulation of nonadiabatic electron excitation in the strong field regime: Linear polyenes.

Time-dependent Hartree-Fock theory has been used to study of the electronic optical response of a series of linear polyenes in strong laser fields. Ethylene, butadiene, and hexatriene have been calculated with 6-31G(d,p) in the presence of a field corresponding to 8.75 x 10(13) W/cm2 and 760 nm. Time evolution of the electron population indicates not only the pi electrons, but also lower lying valence electrons are involved in electronic response. When the field is aligned with the long axis of the molecule, Löwdin population analysis shows large charges at each end of the molecule. For ethylene, the instantaneous dipole moment followed the field adiabatically, but for hexatriene, nonadiabatic effects were very pronounced. For constant intensity, the nonadiabatic effects in the charge distribution, instantaneous dipole, and orbital populations increased nonlinearly with the length of the polyene. These calculations elucidate the mechanism of the strong field nonadiabatic electron excitation of polyatomic molecules leading to their eventual ionization and fragmentation. The described computational methods are a viable tool for studying the complex processes in multielectron atomic and molecular systems in strong laser fields.

Journal Article↗
PubMed2005

Y-STRs haplotypes of Chinese Mongol ethnic group using Y-PLEX 12.

Eleven Y-chromosome STR loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385a,b, DYS438, DYS439) have been co-amplified in 96 healthy unrelated males of Chinese Mongol ethnic group, in order to investigate allele and haplotype frequencies of them, evaluate their usefulness in forensic casework.

China↗
PubMed2005

Organized assemblies in bolaamphiphile/oppositely charged conventional surfactant mixed systems.

Five ionic bolaamphiphiles were synthesized and the aggregation behavior of bola single systems and bola/oppositely charged conventional surfactant mixed systems was studied. Small spherical vesicles were formed in all these mixed systems revealed by transmission electron microscopy (TEM). Variation of the structure of the hydrophobic chain of bolaamphiphiles has great influences on the vesicle formation ability. Vesicles were also found in the single system of a carboxylate bolaamphiphile, which was attributed to the hydrolysis of the bolaamphiphile. The results of FT-IR and X-ray diffraction (XRD) showed that bolaamphiphiles spanned through the vesicle membranes in these mixed systems. Super thermostability of the vesicles in this kind of mixed system was also investigated.

Cations↗
PubMed2005

Population genetics for Y-STRs haplotypes of Chinese Ewenki ethnic minority group.

Chinese Ewenki ethnic minority group, with a population of 26,300 in a statistical survey conducted in 2000, has a lifestyle of nomad, and is distributed across seven counties in the Inner Mongolia Autonomous Region and in Nahe County of Heilongjiang Province of China. The Ewenki people have no written script but a spoken language with three dialects belonging to the Manchu-Tungusic group of the Altai language family. Raising reindeers is the key livelihood of Ewenkis.

China↗
PubMed2004

Hematoporphyrin monomethyl ether photodynamic damage on HeLa cells by means of reactive oxygen species production and cytosolic free calcium concentration elevation.

Hematoporphyrin monomethyl ether (HMME) is a novel and promising porphyrin-related photosensitizer for photodynamic therapy (PDT). HMME-PDT-induced cell death and its mechanisms were investigated in HeLa cells. We demonstrated that HMME-PDT could induce cell death through both necrosis and apoptosis. Sodium azide (the singlet oxygen quencher) or D-mannitol (the hydroxyl radical scavenger) could protect HeLa cells from the apoptosis and necrosis induced by HMME-PDT, showing that reactive oxygen species (ROS), such as singlet oxygen and hydroxyl radical, played a decisive role in HMME-PDT-induced HeLa cells death. Sodium azide or D-mannitol also inhibited HMME-PDT-mediated [Ca2+]i elevation. Cytochrome C (Cyto C) release from mitochondria into cytosol and Caspase-3 activation after HMME-PDT were inhibited by BAPTA/AM (an intracellular calcium chelator). These results demonstrated that ROS generated in HeLa cells by HMME-PDT-induced apoptosis may be through [Ca2+]i elevation which mediates Cyto C release and Caspase-3 activition and initiates the subsequent late stages of apoptosis.

Apoptosis↗
PubMed2004

Dietary soy isoflavones and estrone protect ovariectomized ERalphaKO and wild-type mice from carcinogen-induced colon cancer.

Consumption of soy foods has been weakly associated with reduced colon cancer risk. Colon cancer risk is influenced by estrogen exposure, although the mechanism through which this occurs is not defined. Conversion of estradiol (E2) to estrone (E1) may be protective in the colon. We hypothesized that dietary phytoestrogens, or E1, would reduce colon tumorigenesis via an estrogen receptor (ER)-dependent mechanism. Ovariectomized ERalphaKO or wild-type (WT) female mice were fed diets containing casein (Casein), soy protein without isoflavones (Soy-IF), soy protein + genistein (Soy+Gen), soy protein + NovaSoy (Soy+NSoy) or soy protein + estrone (Soy+E1) from weaning. Colon tumors were induced with azoxymethane. Tumor incidence was affected by diet but not genotype. Colon tumor incidence was lower in ERalphaKO and WT mice fed the Soy+E1 diet compared with those fed the casein or Soy-IF diets. Mice fed Soy+NSoy had a lower tumor incidence than mice fed casein, but not Soy-IF. Genistein did not affect tumor incidence. Soy protein, independently of phytoestrogens or E1, significantly reduced relative colon weight, tumor burden and multiplicity. Relative colon weight was lower (P=0.008) in mice fed Soy+E1 than in the other soy-fed groups. Tumor incidence in this group was lower than in the casein and soy-IF-fed groups and tended to be lower than in the others (P=0.020). Hence, soy protein and NSoy protect mice from colon cancer, and E1 further reduces colon tumorigenesis in mice, independently of ERalpha.

Animals↗
PubMed2004

Attitudes of Chinese medical students toward the global minimum essential requirements established by the Institute for International Medical Education.

BACKGROUND: The Institute for International Medical Education has published "Global Minimum Essential Requirements (GMERs) in Medical Education." PURPOSE: This study examined attitudes of a sample of Chinese medical students toward the GMERs. METHODS: Matriculating and graduating West China School of Medicine Sichuan University medical students were administered parallel surveys during the 2001 to 2002 academic years. RESULTS: Both cohorts produced similar response profiles. The majority in both groups rated the 7 GMER domains as either important or very important for their medical education. Matriculating students rated professional values, attitudes, behavior, and ethics as most important, whereas graduating students valued clinical skills highest. Population health and health systems received the lowest importance ratings from both groups. Please note that this study was conducted before the SARS outbreak. As a result of the SARS experience, attitudes toward population health and health systems might have changed. CONCLUSION: Although medical students ascribe importance to the GMERs, efforts are needed to increase the perceived importance of the population health and health systems domain.

Adult↗
PubMed2003

[Estimate of human visceral adipose area and abdominal subcutaneous adipose area in obese Chinese by simple anthropometric parameters].

OBJECTIVE: To explore the relationship of simple anthropometric parameters with abdominal subcutaneous adipose area (SA) with visceral adipose area (VA), and to generate equations predicting SA and VA by simple anthropometric parameters. METHODS: SA and VA were measured with computed tomography (CT) in 309 human subjects (male 88, female 221). Weight (W), height (H), body mass index (BMI), waist circumference (WC), abdominal circumference (AC), hip circumference (HC) and waist to hip ratio (WHR) were also measured. Multiple stepwise regression analysis was used to generate equations for predicting SA and VA from age and simple anthropometric parameters of 259 subjects (80%, including 181 women and 78 men) randomly selected from the overall sample. These equations were then cross-validated in the remaining 50 subjects (20%, including 40 women and 10 men). RESULTS: The best regression equations for male were developed for predicting SA and VA, and the explanatory variables included WC and age. In women, the equation for predicting SA included AC and BMI; the equation for predicting VA included WHR and W and age. In the cross-validation study, the differences between predicted and observed values of VA in men and women were -7.83% and -6.94%, respectively; the differences between predicted and observed values of SA in men and women were 8.01% and 0.69%, respectively. The goodness of fit between predicted and observed values is good. CONCLUSION: The absolute amount of human VA and SA in obese Chinese can be predicted from anthropometric measurements.

Abdominal Cavity↗
PubMed2002

On the physical origin of blue-shifted hydrogen bonds.

For blue-shifted hydrogen-bonded systems, the hydrogen stretching frequency increases rather than decreases on complexation. In computations at various levels of theory, the blue-shift in the archetypical system, F(3)C-H.FH, is reproduced at the Hartree-Fock level, indicating that electron correlation is not the primary cause. Calculations also demonstrate that a blue-shift does not require either a carbon center or the absence of a lone pair on the proton donor, because F(3)Si-H.OH(2), F(2)NH.FH, F(2)PH.NH(3), and F(2)PH.OH(2) have substantial blue-shifts. Orbital interactions are shown to lengthen the X-H bond and lower its vibrational frequency, and thus cannot be the source of the blue-shift. In the F(3)CH.FH system, the charge redistribution in F(3)CH can be reproduced very well by replacing the FH with a simple dipole, which suggests that the interactions are predominantly electrostatic. When modeled with a point charge for the proton acceptor, attractive electrostatic interactions elongate the F(3)C-H, while repulsive interactions shorten it. At the equilibrium geometry of a hydrogen-bonded complex, the electrostatic attraction between the dipole moments of the proton donor and proton acceptor must be balanced by the Pauli repulsion between the two fragments. In the absence of orbital interactions that cause bond elongation, this repulsive interaction leads to compression of the X-H bond and a blue-shift in its vibrational frequency.

Journal Article↗