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Bin Li

Publications and source records attributed to Bin Li.

At least 73 records · Page 4Linked to original sources
PubMed2006

Shape complexity and fractality of fracture surfaces of swelled isotactic polypropylene with supercritical carbon dioxide.

We have investigated the fractal characteristics and shape complexity of the fracture surfaces of swelled isotactic polypropylene Y1600 in supercritical carbon dioxide fluid through the consideration of the statistics of the regions embedded in the contours at different height of fracture landscapes (also called islands in the literature) of binary scanning electronic micrography images. The probability density functions of the areas A, perimeters L, and shape complexities C (defined by L/2 sqrt piA) of islands are shown to follow power laws p(A) approximately A-(muA+1), p(L) approximately L-(muL+1) and p(C) approximately C-(nu+1), with the scaling ranges spanning over two orders. The perimeter and shape complexity scale respectively as L approx. A(D/2)and C approx. A(q) in two scaling regions delimited by A approximately equal to 10(3). The fractal dimension and shape complexity increase when the temperature decreases. In addition, the relationships among different power-law scaling exponents muA, muB, nu, D, and q have been derived analytically, assuming that A, L, and C follow power-law distributions.

Journal Article↗
PubMed2006

Syntheses, structure, and bonding of Rb14(Mg1-xInx)30. A nonstoichiometric phase with an unusual substitution in the anion framework.

The title compound Rb(14)(Mg(1-x)In(x))(30) (x = 0.79-0.88) has been obtained from high-temperature reactions of the elements in welded Ta tubes. There is no analogous binary compound without Mg. The crystal structure established by single-crystal X-ray diffraction means (space group P2m (No. 189), Z = 1 and a = b = 10.1593(3) Angstroms, c = 17.783(1) Angstroms for x = 0.851) features two distinct types of anionic layers: isolated pentacapped trigonal prismatic In(11)(7-) clusters and condensed [(Mg(x)In(1-x))(5)In(14)](7-) layers. The latter consists of analogous M(11) (M = Mg/In) fragments that share prismatic edges and are interbridged by trigonal M(3) units. The structure shows substantial differences from related A(15)Tl(27) (A = Rb, Cs) in which the cation A that centers a six-membered ring of Tl(11) fragments is replaced by M(3.) Both linear muffin-tin orbital and extended Hückel calculations are used to analyze the observed phase width and site preferences. We further utilize the results to rationalize the distortion of the M(11) fragment in the condensed layer and also to correlate with electrical properties. An isomorphous phase region (Rb(y)K(1-)(y))(14)(Mg(1-x)In(x))(30) (y = 0.52, 0.66 for x = 0.79) is also formed.

Journal Article↗
PubMed2006

Native Thai speakers' acquisition of English word stress patterns.

The influence of syllabic structure, lexical class and stress patterns of known words on the acquisition of the English stress system was investigated in ten native Thai speakers. All participants were adult learners of English with an average length of residence in the US of 1.4 years. They were asked to produce and give perceptual judgments on 40 English non-words of varying syllabic structures in noun and verb sentence frames. Results of the production data suggested that syllables with a long vowel attracted stress more often than syllables containing a short vowel and nouns received initial stress more often than verbs. Additionally, regression analyses with the three factors as predictors suggested that Thai participants' pattern of stress assignment on non-words was significantly influenced by the stress patterns of phonologically similar real words. These results were compared and contrasted to those found in previous work with Spanish-English and Korean-English bilinguals.

Adult↗
PubMed2006

The dynamic change of TGF-beta1 in the myocardial remodeling of rat after myocardial infarction.

To observe the dynamic changes of the TGF-beta1 expressed in the infarct and non-infarcted region of rat heart during the ventricular remodeling (day 3, 7, 28, 180), myocardial infarction rat model was made and relationship between the cytokine and indicator of myocardial remodeling was analyzed. After the detection of hemodynamic parameter was performed by the Powerlab devices, the size of myocardial infarction and the morphology change was detected by TTC and HE, respectively. The relative levels of mRNA of TGF- beta1, collagen type I, III, and fetal gene beta-MHC were detected by RT-PCR. The distribution of TGF- beta1 protein in the myocardium was detected by immunohistochemistry. The results showed that the size of infarction was higher than that of the sham operated groups in the infarcted group (44.5 +/- 0.5 vs 0). The difference in hemodynamic parameters between the infarcted group and sham operated group was significant (P < 0.01). HE staining showed that inflammatory cells were accumulated in the infarcted region at the beginning of the 3rd day, which lasted 4 weeks. Then, it decreased gradually. beta-MHC in the non-infarcted region rose from the 3rd day, reaching its peak at the 4th week, and it decreased gradually. The ratio of the collagen type I/III showed similar changes as compared with the sham operated groups (P < 0.01). And the relative mRNA levels in the non-infarcted group were significantly higher than that in the infarcted and sham operated group (P < 0.01) at day 180. Linear regression analysis indicated that the TGF-beta1 was positively correlated with the ventricular remodeling. It was concluded that the cytokine TGF-beta1 participates in the process of the myocardial remodeling, which could be a strategy in the interference of myocardial remodeling.

Animals↗
PubMed2006

Feeder layer- and serum-free culture of rhesus monkey embryonic stem cells.

The common culture system of rhesus monkey embryonic stem (rES) cells depends largely on feeder cells and serum, which limits the research and application of rES cells. This study reports a feeder layer-free and serum-free system for culture of rES cells. rES cells could be cultured through at least 22 passages on laminin in medium supplemented with serum replacement (SR), basic fibroblast growth factor (bFGF) and transforming growth factor beta1 (TGFbeta1), and maintained stable proliferation rates and normal karyotypes, while displaying all the embryonic stem cell characteristics including morphology, alkaline phosphatase (AKP), Oct-4, cell surface markers SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81, and formed cystic embryoid bodies in vitro. In addition, the studies showed that TGFbeta1, bFGF and laminin are necessary for maintaining the undifferentiated growth of rES cells in long-term culture. Moreover, withdrawal of TGFbeta1 increased the differentiation rate by decreasing the expression of integrins. Therefore, this system would provide a well-defined culture system for rES cells, and would facilitate research into self-renewal and differentiation mechanisms of rES cells.

Animals↗
PubMed2006

Immobilization of Pycnoporus sanguineus laccase on copper tetra-aminophthalocyanine-Fe(3)O(4) nanoparticle composite.

A magnetic nanoparticle composite of CuTAPc (copper tetra-aminophthalocyanine)-Fe(3)O(4) was prepared by in situ complexation and was characterized by FTIR (Fourier-transform IR) spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, FESEM (field emission scanning electron microscopy) micrograph and hysteresis loop. The results showed that CuTAPc formed the covering layer on the surface of the composite. Using glutaraldehyde, laccase was covalently attached to the surface of the composite. When white-rot-fungus (Pycnoporus sanguineus) laccase was immobilized on the CuTAPc-Fe(3)O(4) nanoparticle composite in PBS, the optimal reaction pH was 5.0 and the optimal temperature was 0 degrees C. When 2.0 mg/ml laccase solution was used, the immobilization yield was 20%. The activity, K(m), k(cat)/K(m) and V(max) values of the immobilized laccase were 1.43 units/mg, 2.38 x 10(-5) mol/l, 2.1 x 10(3) mol(-1) x s(-1) x l and 1.19 x 10(-6) mol x l(-1) /x min(-1) respectively. The system exhibited maximum enzyme activity at pH 3.0 and at 45 degrees C. After storage at 4 degrees C for 1 month, the residual activity of the immobilized laccase was 85% of its initial activity, while that of free laccase was only 30%. During 240 min incubation at 55 degrees C, the activity of immobilized laccase quickly increased to a maximum after 150 min and then decreased to 95% in the next 90 min, while the activity of the free enzyme decreased monotonically to 28%. After five consecutive operations, the immobilized laccase still retained 80% of its initial activity.

Arecaceae↗
PubMed2006

An improved electronic colon cleansing method for detection of colonic polyps by virtual colonoscopy.

Electronic colon cleansing (ECC) aims to segment the colon lumen from a patient abdominal image acquired using an oral contrast agent for colonic material tagging, so that a virtual colon model can be constructed. Virtual colonoscopy (VC) provides fly-through navigation within the colon model, looking for polyps on the inner surface in a manner analogous to that of fiber optic colonoscopy. We have built an ECC pipeline for a commercial VC navigation system. In this paper, we present an improved ECC method. It is based on a partial-volume (PV) image-segmentation framework, which is derived using the well-established statistical expectation-maximization algorithm. The presented ECC method was evaluated by both visual inspection and computer-aided detection of polyps (CADpolyp) within the cleansed colon lumens obtained using 20 patient datasets. Compared to our previous ECC pipeline, which does not sufficiently consider the PV effect, the method presented in this paper demonstrates improved polyp detection by both visual judgment and CADpolyp measure.

Algorithms↗
PubMed2006

FOXP3 ensembles in T-cell regulation.

Our recent studies have identified dynamic protein ensembles containing forkhead box protein 3 (FOXP3) that provide insight into the molecular complexity of suppressor T-cell activities, and it is our goal to determine how these ensembles regulate FOXP3's transcriptional activity in vivo. In this review, we summarize our current understanding of how FOXP3 expression is induced and how FOXP3 functions in vivo as a transcriptional regulator by assembling a multisubunit complex involved in histone modification as well as chromatin remodeling.

Animals↗
PubMed2006

Integrating software into PRA: a software-related failure mode taxonomy.

Probabilistic risk assessment is a methodology to assess the probability of failure or success of a mission. Results provided by the risk assessment methodology are used to make decisions concerning choice of upgrades, scheduling of maintenance, decision to launch, etc. However, current PRA neglects the contribution of software to the risk of failure of the mission. Our research has developed a methodology to account for the impact of software to system failure. This article focuses on an element of the approach: a comprehensive taxonomy of software-related failure modes. Application of the taxonomy is discussed in this article. A validation of the taxonomy and conclusions drawn from this validation effort are described. Future research is also summarized.

Journal Article↗
PubMed2006

The antimalarial artemisinin synergizes with antibiotics to protect against lethal live Escherichia coli challenge by decreasing proinflammatory cytokine release.

In the present study artemisinin (ART) was found to have potent anti-inflammatory effects in animal models of sepsis induced by CpG-containing oligodeoxy-nucleotides (CpG ODN), lipopolysaccharide (LPS), heat-killed Escherichia coli 35218 or live E. coli. Furthermore, we found that ART protected mice from a lethal challenge by CpG ODN, LPS, or heat-killed E. coli in a dose-dependent manner and that the protection was related to a reduction in serum tumor necrosis factor alpha (TNF-alpha). More significantly, the administration of ART together with ampicillin or unasyn (a complex of ampicillin and sulbactam) decreased mortality from 100 to 66.7% or 33.3%, respectively, in mice subjected to a lethal live E. coli challenge. Together with the observation that ART alone does not inhibit bacterial growth, this result suggests that ART protection is achieved as a result of its anti-inflammatory activity rather than an antimicrobial effect. In RAW264.7 cells, pretreatment with ART potently inhibited TNF-alpha and interleukin-6 release induced by CpG ODN, LPS, or heat-killed E. coli in a dose- and time-dependent manner. Experiments utilizing affinity sensor technology revealed no direct binding of ART with CpG ODN or LPS. Flow cytometry further showed that ART did not alter binding of CpG ODN to cell surfaces or the internalization of CpG ODN. In addition, upregulated levels of TLR9 and TLR4 mRNA were not attenuated by ART treatment. ART treatment did, however, block the NF-kappaB activation induced by CpG ODN, LPS, or heat-killed E. coli. These findings provide compelling evidence that ART may be an important potential drug for sepsis treatment.

Animals↗
PubMed2006

Physical mapping of the blue-grained gene(s) from Thinopyrum ponticum by GISH and FISH in a set of translocation lines with different seed colors in wheat.

The original blue-grained wheat, Blue 58, was a substitution line derived from hybridization between common wheat (Triticum aestivum L., 2n=6x=42, ABD) and tall wheatgrass (Thinopyrum ponticum Liu & Wang=Agropyron elongatum, 2n=10x=70, StStEeEbEx), in which one pair of 4D chromosomes was replaced by a pair of alien 4Ag chromosomes (unknown group 4 chromosome from A. ponticum). Blue aleurone might be a useful cytological marker in chromosome engineering and wheat breeding. Cytogenetic analysis showed that blue aleurone was controlled by chromosome 4Ag. GISH analysis proved that the 4Ag was a recombination chromosome; its centromeric and pericentromeric regions were from an E-genome chromosome, but the distal regions of its two arms were from an St-genome chromosome. On its short arm, there was a major pAs1 hybridization band, which was very close to the centromere. GISH and FISH analysis in a set of translocation lines with different seed colors revealed that the gene(s) controlling the blue pigment was located on the long arm of 4Ag. It was physically mapped to the 0.71-0.80 regions (distance measured from the centromere of 4Ag). The blue color is a consequence of dosage of this small chromosome region derived from the St genome. We speculate that the blue-grained gene(s) could activate the anthocyanin biosynthetic pathway of wheat.

Chromosomes, Plant↗
PubMed2006

Three new and antitumor anthraquinone glycosides from Lasianthus acuminatissimus MERR.

Three new anthraquinone glycosides, lasianthuoside A (1), B (2), and C (3), were isolated from the root of Lasianthus acuminatissimus MERR., The structural elucidation of these anthraquinones was mainly established on the basis of 1D and 2D NMR and HR-MS spectroscopic analysis. Ten known compounds, damnacanthol (4), damnacanthol 11-methyl ether (5), damnacanthol-3-O-beta-D-primeveroside (6), asperuloside (7), asperulosidic acid (8), deacetyl asperulosidic acid (9), a nonglycosidic iridoid (10), 2,6-dimethoxy-4-hydroxyphenol-1-O-beta-D-glucopyranoside (11), tachioside (methoxyhydroquinone-4-O-beta-D-glucopyranoside) (12), and isotachioside (methoxyhydroquinone-1-O-beta-D-glucopyranoside) (13) were also identified for the first time from this plant in the course of the phytochemical and spectroscopic investigation. In addition to this report, a preliminary evaluation of 13 compounds in treating rheumatoid arthritis and antitumor effects of six anthraquinones are presented.

Animals↗
PubMed2006

Production of the butyrylcholinesterase knockout mouse.

The butyrylcholinesterase (BChE [EC 3.1.1.8]) knockout mouse is a model for BChE deficiency in humans. The existence of genetic variants of human BChE was discovered after a new muscle relaxant, succinylcholine, was introduced into the practice of medicine in the late 1950s. People with the atypical variant were unable to breathe for 2 h after receiving a dose intended to paralyze for 3-5 min (Kalow and Gunn, 1957, 1959). The atypical variant was later found to have a single-amino-acid mutation at Asp-70 (McGuire et al., 1989), which decreased the affinity of BChE for all positively charged compounds. Though the atypical BChE mutant is the one most commonly encountered in cases of succinylcholine apnea, an additional 58 mutations in the BChE coding sequence have been reported. The frequency of BChE mutations in the American population is known (Lockridge, 1990). One person out of 25 carries one atypical allele (D70G), whereas 1 out of 2500 is homozygous for D70G. The most frequent mutation, A539T, is carried by 1 person out of every 4 and is found in homozygous form in 1 person out of 69 (Bartels et al., 1992). The homozygous A539T form is associated with a 33% decrease in plasma BChE activity. Some people have no detectable BChE activity in plasma, owing to a mutation that truncates the protein, or inactivates it. The frequency of silent BChE is 1 out of 160 for carriers, and 1 out of 110,000 for homozygotes. The BChE knockout mice are models for silent BChE in humans. The literature contains no documentation of the health of people with silent BChE, other than to say they are healthy. We know nothing about their life expectancy, fertility, risk of cognitive impairment, risk of heart disease, or susceptibility to toxins. The BChE knockout mouse will allow us to test the hypothesis that the function of BChE is to detoxify poisons and will allow us to test the role of BChE in other physiological functions.

Alternative Splicing↗
PubMed2006

Gene transfer of acetylcholinesterase protects the knockout mouse from the toxicity of DFP.

Acetylcholinesterase (AChE) has a clear role in nerve impulse transmission. Organophosphorus esters are highly toxic chemicals used as pesticides, fire retardants, plasticizers, and chemical warfare agents. The acute toxicity of organophosphorus poisons is attributed to inhibition of AChE in nerve synapses. This leads to seizures, respiratory arrest, and death. Our goal was to find a new therapeutic for protection against the toxicity of organophosphates (OPs). We investigated the feasibility of using a gene therapy vector to deliver AChE over long time periods and in quantities sufficiently high to provide protection against diisopropylfluorophosphate (DFP) toxicity. We used the AChE-/- mouse for these studies because this mouse has no endogenous AChE activity (Xie et al., 2000). Any AChE activity found in tissues could only come from the viral vector.

Acetylcholinesterase↗
PubMed2006

The origin and in vivo significance of murine and human culture-expanded endothelial progenitor cells.

In adults highly purified populations of early hematopoietic progenitors or cells derived from ex vivo expanded unmobilized human peripheral blood mononuclear cells contribute to new blood vessel formation. However, the source of these culture-expanded endothelial progenitor cells (CE-EPCs) remains controversial. We demonstrate that ex vivo expansion of unmobilized human peripheral blood generated CE-EPCs with similar numbers, kinetics, and antigen expression profile as compared to plating unfractionated CD34(+)/lin(-)-enriched bone marrow mononuclear cells. Both CE-EPC populations uniformly co-expressed myeloid and endothelial markers, suggesting that peripheral blood progenitor enumeration does not correlate with the numbers of early outgrowth CE-EPCs. Using purified myeloid subpopulations obtained from mice harboring the lacZ transgene driven by an endothelial-specific promoter, we showed that the immature myeloid lineage marker CD31(+) cells generated CE-EPCs with fourfold greater frequency than mature myeloid populations. Biphenotypic cells co-expressing myeloid/endothelial antigens were not detected in circulating human or murine peripheral blood or bone marrow but were associated with murine tumors. Unlike CE-EPCs, CD14(+) leukocytes admixed within tumors did not generate vWF-positive blood vessels during a similarly defined period of tumor growth, but some leukocytes up-regulated the endothelial marker VE-cadherin. Taken together, the data suggest that the local neovascular microenvironment may facilitate vasculogenesis by promoting endothelial differentiation and that CE-EPCs may accelerate such vasculo-genesis.

Animals↗
PubMed2006

[Expression of Cyt C in brain of rats poisoned by tetramine].

OBJECTIVE: To investigate the evidence for the judgement on legal cases of intoxication by tetramine. METHODS: Fifty rats given tetramine by lavage were sacrificed at different time after intoxication. The expression of Cyt C was detected by immunohistochemistry, and the reasults were assessed by an image analysis system. RESULTS: There was a slight expression of Cyt C in control group. In intoxication group the expression of Cyt C increased after the rats were given tetramine for 30 minutes; it reached the peak at 24 hours after intoxication and kept up the level for 3 days, then it began to decrease and returned to the control level in 10 days. CONCLUSION: The regular change of Cyt C expression might be a useful sign for assessment in legal cases of intoxication by tetramine.

Animals↗
PubMed2006

[Change of brainstem auditory evoked potential with different stimulating frequencies after closed diffuse brain injuries of rat].

UNLABELLED: OBJECTIVE To investigate the change of peak latency (PL), interpeak latency (IPL) and peak latency ratio (PL ratio) of brainstem auditory evoked potential (BAEP) with different stimulating frequencies after closed diffuse brain injuries of rat,and provide experimental evidence for clinical diagnosis of traumatic brain injury in early stage and also for Forensic practice. METHODS: A rat model for closed diffuse brain injury was successfully constructed by hit the parietal bone with a spring-driven steel stick. The auditory brainstem response (ABR) evoked by clicking with low stimulating frequency of 10 Hz and high stimulating frequency of 50 Hz were respectively recorded at 6 h, 12 h, 2 d, 4 d after brain injury. The results of experimented group were compared with those of control group. RESULTS: The 2 d, 4 d V PL and the 6 h, 12 h, 2 d, 4 d III-V IPL of BAEP with 50 Hz stimulating frequency of model group became longer than those of control group (P < 0.05), but there was no significant difference observed between model and control group experimented with low stimulating frequency of 10 Hz (P > 0.05). The PL ratio of III/I, IV/I, V/I, IV/III and V/III with different stimulating frequencies had no significant postinjury changes. Conclusion The high stimulating frequency of BAEP is a reliable test for diagnosis of TBI in early period. Its sensitivity is superior to the low simulating frequency.

Animals↗