World J Gastroenterol
January 2010
Aim: To evaluate the suitability of rupintrivir against Enterovirus 71 (EV71) induced severe clinical symptoms using computational methods.
Methods: The structure of EV71 3C protease was predicted by homology modeling. The binding free energies between rupintrivir and EV71 3C and human rhinovirus 3C protease were computed by molecular dynamics and molecular mechanics Poisson-Boltzmann/surface area and molecular mechanics generalized-born/surface area methods.
Biomaterials
March 2010
Due to the lack of appropriate scaffolds, the in vitro engineering of cartilage tissue with a sophisticated structure, such as a human ear, remains a great challenge. Although polyglycolic acid (PGA) has become one of the most successful scaffolds for cartilage regeneration, how to overcome its limitations in achieving desirable mechanical strength and accurate control over shape remains an unsolved problem. In this study, the mechanical strength of PGA scaffold was enhanced by coating with polylactic acid (PLA).
View Article and Find Full Text PDFZhonghua Yi Xue Yi Chuan Xue Za Zhi
August 2009
Objective: To investigate the association of gene polymorphism of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) with ulcerative colitis (UC) in Chinese.
Methods: One hundred and seventeen patients with UC and 246 healthy controls were genotyped for the polymorphisms of C-658T in the promoter and C61T at the 3' untranslated region of the CTLA-4 gene using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), respectively. The genotype and allele frequencies of the two groups were calculated and compared by chi square test.
Neuropsychologia
January 2010
This study investigated the influence of the symbol type and numerical distance of numbers on the amplitudes and peak latencies of event-related potentials (ERPs). Our aim was to (1) determine the point in time of magnitude information access in visual number processing; and (2) identify at what stage the advantage of Arabic digits over Chinese verbal numbers occur. ERPs were recorded from 64 scalp sites while subjects (n=26) performed a classification task.
View Article and Find Full Text PDFA key issue in stem cell biology is the differentiation of homogeneous stem cells towards different fates which are also organized into desired configurations. Little is known about the mechanisms underlying the process of periodic patterning. Feather explants offer a fundamental and testable model in which multi-potential cells are organized into hexagonally arranged primordia and the spacing between primordia.
View Article and Find Full Text PDFDent Mater
November 2009
Objectives: This study was designed to evaluate the cytotoxicity of several resin-based cements (Panavia F, Super-Bond C&B, Chemiace II) after polymerization on cultured human dental pulp cells.
Methods: After polymerization, specimens from three resin-based cements were eluted with fresh Dulbecco's modified Eagle's medium (DMEM) without serum for 72 h, at 37 degrees C, using 0.4 g of each substance per milliliter of fresh medium.
Background And Aim: Cytotoxic T lymphocyte antigen-4 (CTLA-4) plays a role in the downregulation of T cell activation. The present study aimed to examine an association between the CTLA-4 gene polymorphisms and ulcerative colitis (UC) in the Han Chinese in central China.
Materials And Methods: One hundred seventeen patients with UC and 246 healthy controls were genotyped for CTLA-4 gene -658CT in the promoter and CT61 at the 3' untranslated region using a method of polymerase chain reaction-based restriction fragment length polymorphism and single-strand conformation polymorphism, respectively.
The application of in vitro engineered cartilage has become a promising approach to repair cartilage defects. Nevertheless, the poor mechanical properties of in vitro engineered cartilage limit its potential for clinical applications. Studies have shown that the extracellular matrix (ECM) components are strongly correlated with the mechanical strength of engineered cartilage, but it remains unclear which components play a key role in determining the mechanical property of engineered cartilage.
View Article and Find Full Text PDFZhonghua Kou Qiang Yi Xue Za Zhi
April 2008
Zhonghua Nei Ke Za Zhi
March 2008
Objective: To investigate the association between the exon 2, 3, 4 of MHC class I chain-related gene-B (MICB) and ulcerative colitis (UC) in Chinese Han.
Methods: Using polymerase chain reaction single-stranded conformation polymorphism, allele frequency of MICB exon 2, 3 and 4 in 105 patients with UC and 213 age and sex matched healthy controls were genotyped. All of the studied individuals were Chinese Han.
In this article, a new method for the determination of triazine herbicides atrazine and simazine in environment aqueous samples was developed. It was based on solid-phase extraction (SPE) using bamboo charcoal as adsorbent and high-performance liquid chromatography-ultraviolet detector (HPLC-UV) for the enrichment and determination of atrazine and simazine at trace level. Related important factors influencing the extraction efficiency, such as the kind of eluent and its volume, flow rate of the sample, pH of the sample, and volume of the sample, were investigated and optimized in detail.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
April 2008
The interaction between alpinetin and human serum albumin (HSA) was studied by fluorescence and UV/Vis absorption spectroscopy. The results revealed that alpinetin caused the fluorescence quenching of HSA through a dynamic quenching procedure. The quenching constant was obtained at various temperatures.
View Article and Find Full Text PDFThis paper describes a novel, simple and environmentally friendly method for rapid determination of the amide herbicides metoalchlor, acetochlor, and butachlor. It is based on dispersive liquid-liquid microextraction and gas chromatography-mass spectrometry. Factors that may influence the enrichment efficiency, such as type and volume of extraction solvent, type and volume of dispersive solvent, extraction time, and content of NaCl, were investigated and optimized in detail.
View Article and Find Full Text PDFHow language experience affects visual word recognition has been a topic of intense interest. Using event-related potentials (ERPs), the present study compared the early electrophysiological responses (i.e.
View Article and Find Full Text PDFUsing Stroop-like tasks, this study examined whether Chinese kindergartners showed automatic processing of numerical magnitude. A total of 36 children (mean age = 5 years 10 months) were asked to perform physical size comparison (i.e.
View Article and Find Full Text PDFHollow-fiber liquid-phase microextraction (HF-LPME), a relatively new sample preparation technique, has attracted much interest in the field of environmental analysis. In the current study, a novel method based on hollow-fiber liquid-phase microextraction with in situ derivatization and gas chromatography-mass spectrometry for the measurement of triclosan in aqueous samples is described. Hollow-fiber liquid-phase microextraction conditions such as the type of extraction solvent, the stirring rate, the volume of derivatizing reagent, and the extraction time were investigated.
View Article and Find Full Text PDFA subgroup of the TNF receptor family, composed of Edar, Troy and Xedar, are implicated in the development of ectodermal appendages, such as hair follicles, teeth and sweat glands. We have isolated chicken orthologues of these three receptors and analysed their roles in early feather development. Conservation of protein sequences between mammalian and avian proteins is variable, with avian Edar showing the greatest degree of sequence identity.
View Article and Find Full Text PDFZhonghua Kou Qiang Yi Xue Za Zhi
November 2006
Objective: To compare the central nervous system processing of orofacial pain patients who might have atypical pain (group 1) after occlusal treatment with those patients who had synovitis pain of temporomandibular disorders (TMD) (group 2).
Methods: Seven patients in each group were included in this study. Ten painless normal subjects (group 3) were employed as a control group.
Temporomandibular disorders (TMD) represent a group of chronic painful conditions in the masticatory musculature and temporomandibular joint. To examine possible changes in cortical machinery in TMD patients, we compared neuromagnetic signals evoked by cortical neurons between healthy subjects and TMD patients while they were carefully observing the video frames of jaw-opening movements performed by another person. During the movement observation task in the healthy subjects, we found cortical activation in the following sequence with left hemisphere dominance: (1) the occipitotemporal region near the inferior temporal sulcus (human homologue of MT/V5 in monkeys), (2) the inferior parietal cortex (IPC), and (3) the anterior part of the inferior-lateral precentral gyrus (PrCG).
View Article and Find Full Text PDFA novel purge-and-trap method coupled with gas chromatography-mass spectrometry (GC-MS) is developed for the analysis of trace and ultratrace phenols based on their derivatization with acetic anhydride. Parameters affecting the extraction efficiency, such as purge temperature, concentration of sodium chloride, purge time, and volume of derivatization reagent, were investigated. The optimized conditions were addition of 150 microL acetic anhydride, purge time of 25 min at the purge temperature of 60 degrees C with 30% NaCl.
View Article and Find Full Text PDFThe development and regeneration of feathers have gained much attention recently because of progress in the following areas. First, pattern formation. The exquisite spatial arrangement provides a simple model for decoding the rules of morphogenesis.
View Article and Find Full Text PDFNeuropsychologia
September 2006
This study compared the event-related potentials elicited by single-digit addition, subtraction, and multiplication problems. With a delayed verification paradigm, 18 Chinese undergraduates were first asked to solve the arithmetic problems that were presented visually for 200 ms and, after 1.5 s, to judge whether a presented solution was correct or not.
View Article and Find Full Text PDFThe event-related potential technique was used to investigate the time course and scalp-potential topography for the numerical distance effect in a number-matching task. Twenty undergraduates judged whether a number matched or did not match another number presented 1.5 s earlier.
View Article and Find Full Text PDFDespite numerous studies on the neural basis of numerical processing, few studies have examined the neural substrates of one of the most basic numerical processing-number sequence recitation. The present study used fMRI to investigate neural substrates of number sequence recitation, focusing on the intraparietal sulcus (IPS) and perisylvian areas. This study used a 2 (number versus alphabet) x 2 (forward versus backward recitation) design.
View Article and Find Full Text PDFThis paper demonstrates headspace liquid-phase microextraction (HS-LPME) as used for the determination of volatile residual solvents in pharmaceutical products. This method is based on headspace liquid-phase microextraction capillary column gas chromatography. Under optimum conditions, the linerary of the method ranged from 1 to 1,000 mg l(-1).
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