Synthesis, Characterization of Low Molecular Weight Chitosan Selenium Nanoparticles and Its Effect on DSS-Induced Ulcerative Colitis in Mice.

Selenium nanoparticles have attracted extensive attention due to their good bioavailability and activity. In the present study, a new form of selenium nanoparticle (Low molecular weight chitosan selenium nanoparticles (LCS-SeNPs)) were synthesized in a system of sodium selenite and acetic acid. The size, element state, morphology and elementary composition of LCS-SeNPs were characterized by using various spectroscopic and microscopic measurements.

[Development and Design of Portable Sleep Electroencephalogram Monitoring System].

The growing rate of public health problem for increasing number of people afflicted with poor sleep quality suggests the importance of developing portable sleep electroencephalogram (EEG) monitoring systems. The system could record the overnight EEG signal, classify sleep stages automatically, and grade the sleep quality. We in our laboratory collected the signals in an easy way using a single channel with three electrodes which were placed in frontal position in case of the electrode drop-off during sleep.

Temporal integration reflected by frequency following response in auditory brainstem.

Auditory temporal integration (ATI) has been widely described in psychoacoustic studies, especially for loudness perception. Loudness increases with increasing sound duration for durations up to a time constant about 100 ~ 200 ms, and then loudness becomes saturated with more duration increase. However, the electrophysiological mechanism underlying the ATI phenomenon has not been well understood.

A study of sleep staging based on a sample entropy analysis of electroencephalogram.

In this paper we report a detection method for different sleep stages and it is based on a single-channel electroencephalogram (EEG) system. The system is simple and can be easily setup in homes to perform sleep EEG recording, overnight sleep EEG automatic staging, and sleep quality evaluation. EEG data of 14 sleeping subjects were recorded through the entire night.

Pitch perception of concurrent harmonic tones with overlapping spectra.

Fundamental frequency difference limens (F0DLs) were measured for a target harmonic complex tone with nominal fundamental frequency (F0) of 200 Hz, in the presence and absence of a harmonic masker with overlapping spectrum. The F0 of the masker was 0, ± 3, or ± 6 semitones relative to 200 Hz. The stimuli were bandpass filtered into three regions: 0-1000 Hz (low, L), 1600-2400 Hz (medium, M), and 2800-3600 Hz (high, H), and a background noise was used to mask combination tones and to limit the audibility of components falling on the filter skirts.

Partial transfection of cells using laminar flows in microchannels.

This manuscript describes a convenient method for partial transfection using a Y-shaped microchannel polydimethylsiloxane (PDMS)-glass chip and on-chip cationic lipid-mediated transfection. Enhanced green fluorescent protein genes (pEGFP-N2) were introduced into the COS-7 cells cultured in half of the channel, while red fluorescent protein genes (pDsRed-N1) were introduced into the cells cultured in another half of the channel. This on-chip partial transfection technique provides an avenue for the spatial control of transfection.

Curvelet processing of MRI for local image enhancement.

Magnetic resonance imaging provides very good contrast between different soft tissues; however, in some cases, this technique is not so suitable to image calcified structures like bones. The quality of images is often degraded by blur edges or noises, which makes it difficult to accurately identify bone structures. In this paper, we proposed a new curvelet preprocessing method for local image enhancement to especially improve the quality of spinal MRI.

Cochlear-implant spatial selectivity with monopolar, bipolar and tripolar stimulation.

Sharp spatial selectivity is critical to auditory performance, particularly in pitch-related tasks. Most contemporary cochlear implants have employed monopolar stimulation that produces broad electric fields, which presumably contribute to poor pitch and pitch-related performance by implant users. Bipolar or tripolar stimulation can generate focused electric fields but requires higher current to reach threshold and, more interestingly, has not produced any apparent improvement in cochlear-implant performance.

A statistical study of the factors influencing the extent of respiratory motion blur in PET imaging.

Respiratory motion results in significant motion blur in thoracic and abdomen PET imaging. The extent of respiratory motion blur is mainly correlated with breathing amplitude, tumor size and location. In this paper we introduce a statistical study to quantitatively show the factors influencing the extent of respiratory motion blur in thoracic PET images.

Respiratory motion blur identification and reduction in ungated thoracic PET imaging.

Respiratory motion results in significant motion blur in thoracic positron emission tomography (PET) imaging. Existing approaches to correct the blurring artifact involve acquiring the images in gated mode and using complicated reconstruction algorithms. In this paper, we propose a post-reconstruction framework to estimate respiratory motion and reduce the motion blur of PET images acquired in ungated mode.

Reference values for amplitude-integrated EEGs in infants from preterm to 3.5 months of age.

Objectives: Amplitude-integrated electroencephalogram (aEEG) is a valuable tool for the continuous evaluation of functional brain maturation in infants. The amplitudes of the upper and lower margins of aEEGs are postulated to change with maturation and correlate with postmenstrual age (PMA). In this study we aimed to establish reliable reference values of aEEG amplitudes, which provide quantitative guidelines for assessing brain maturation as indicated by aEEG results in neonates and young infants.

[Mathematical model of bursting spike train and its spectrum features].

Bursting is an important firing mode of neurons. To propose a stochastic model of bursting spike train, the interspike interval (ISI) characteristics of single-spiking train and bursting spike train were analyzed and compared. In contrast with the exponential distribution of ISI in single-spiking train, normal distribution is supposed to be the ISI model of bursting spike train.

[Advances in the study of virtual channels of cochlear implant].

This paper discusses virtual channels of cochlear implant, which is produced by simultaneous or sequential activation of adjacent cochlear implant electrodes. Virtual channels create and transfer more available spectral pitch information with the limited number of fixed electrodes, which can be recognized as pitch percepts intermediate to those produced by each electrode separately. This technique not only utilizes the interaction of electrodes but also increases the number of place-pitch steps available to cochlear implant listeners.

[Evaluating fatigue resistance effect of health food by near-infrared tissue oximeter].

Currently, chronic fatigue syndrome (CFS) seriously affects people's normal living and work. In the present paper, the physiological parameters, such as tissue oxygenation saturation and heart rate, were used to evaluate the subjects' fatigue degree, and the fatigue resistance capsule and coffee were taken as a measure to adjust the fatigue. Human tissue oxygen saturation (rSO2) can be monitored noninvasively and in real time by near infrared spectroscopy (NIRS) based on spatially-resolved spectroscopy.

[An overview of the studies on combined electric and acoustic stimulation of auditory system].

This paper discusses the technology of combined electric and acoustic stimulation (EAS) of the auditory system, which is a new therapy for the patients suffering from severe to profound high- and mid-frequency hearing loss but still having their low-frequency hearing. EAS uses hearing aid and cochlear implant technology together in the same ear. The hearing aid acoustically amplifies at low-frequencies, while the cochlear implant electrically stimulates at mid- and high-frequencies.

Application of Tsallis entropy to EEG: quantifying the presence of burst suppression after asphyxial cardiac arrest in rats.

Burst suppression (BS) activity in EEG is clinically accepted as a marker of brain dysfunction or injury. Experimental studies in a rodent model of brain injury following asphyxial cardiac arrest (CA) show evidence of BS soon after resuscitation, appearing as a transitional recovery pattern between isoelectricity and continuous EEG. The EEG trends in such experiments suggest varying levels of uncertainty or randomness in the signals.

An easy protocol for on-chip transfection of COS-7 cells with a cationic lipid-based reagent.

The microchip has become a miniaturized and integrated platform for cell research and gene analysis. Traditional biological experiments are being performed on chips with greater frequency. Transfection, which is the process of introducing foreign DNA (or RNA) into cultured mammalian cells, is an important tool for basic and applied life science research.

Self-organizing map-based multi-thresholding on neural stem cells images.

Automatic segmentation and tracking systems can be useful tools for biologists to monitor and understand the proliferation and the differentiation of neural stem cells. This paper applied the self-organizing map-based multi-thresholding on the neural stem cells images. Using local variance as the local spatial feature and quadtree decomposition as the sub-sampling method, inner-cell regions, cell borders and background can be roughly classified.

Neurodevelopment in newborns: a sample entropy analysis of electroencephalogram.

The present paper investigates the neural ontogeny of newborns in view of electroencephalogram (EEG) complexity during active sleep (AS) and quiet sleep (QS). Sample entropy (SampEn) is applied to EEG recordings from 168 newborns with postmenstrual age (PMA) ranging from 25 to 60 weeks. The relationship between neurodevelopment and PMA is then explored according to the statistical analysis of the median and interquartile range of SampEn curves.

Cerebral hypoxic ischemia at different cerebral oxygen saturations in piglets: amplitude-integrated EEG study.

Objective: the objective of present paper was to study the amplitude-integrated EEG (aEEG) in hypoxic ischemic (HI) animal models and to test the reliability of aEEG method when used to monitor cerebral injuries.

Method: HI animal models were constructed and classified into mild, moderate and severe cerebral oxygen saturation groups according to regional oxygen saturation (rSO(2)) in brains. Then aEEG waveforms were obtained from raw EEG data using digital signal processing.

[The application of amplitude-integrated EEG in the cerebral function monitoring of neonates].

Amplitude-integrated electroencephalogram (aEEG) which is a simplified form of standard EEG has been increasingly used in neonates. The aEEG method is easy to apply and to interpret and the simplicity of the method makes it feasible for "round the clock" recording. The present paper briefly introduces the signal acquisition, data analysis and clinical applications of aEEG.

[Optimally designing the probe of the near infrared oximeter to detect human tissue oxygen saturation non-invasively].

Human tissue oxygen saturation (rSO2) can be monitored non-invasively and in real time by near infrared spectroscopy (NIRS) based on spatially-resolved spectroscopy. To expand the clinical applications of the NIRS oximeter developed by our group based on the above principle, the accuracy of rSO2 must be ensured and enhanced as far as possible. In the present paper, the influences of the probe configuration, especially the distance between the detectors and the wavelength discreteness of the light source, on the accuracy of rSO2 were discussed.

[Study on the effect of spectral details encoding in speech processing on Mandarin recognition for cochlear implants users with speech maskers].

The modern multi-channel cochlear implant devices produce good speech recognition scores in quiet. However, the ability of most implant users to understand speech with the speech maskers remains quite poor. The goal of this study is to investigate the effect of spectral details encoding in speech processing on Mandarin recognition based on various acoustic models.

On alpha-divergence based nonnegative matrix factorization for clustering cancer gene expression data.

Objective: Nonnegative matrix factorization (NMF) has been proven to be a powerful clustering method. Recently Cichocki and coauthors have proposed a family of new algorithms based on the alpha-divergence for NMF. However, it is an open problem to choose an optimal alpha.

Reducing microarray data via nonnegative matrix factorization for visualization and clustering analysis.

In microarray data analysis, each gene expression sample has thousands of genes and reducing such high dimensionality is useful for both visualization and further clustering of samples. Traditional principal component analysis (PCA) is a commonly used method which has problems. Nonnegative Matrix Factorization (NMF) is a new dimension reduction method.