1,110 research outputs found

    Study on the anti-cerebral ischemia effect of borneol and its mechanism

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    Background: Borneol is the processed item from resin of Dryobalanops aromatica Gaertn. f. It can enhance the activity of antioxidant enzymes in brain tissue and reduce inflammatory response by improving the energy metabolism of ischemic brain regions, and thereby reduces brain tissue damage. The objective of this paper was to study the anti-cerebral ischemia effect of borneol and its mechanism.Materials and Methods: The anti-cerebral ischemia effect of borneol was studied by ligation of bilateral common carotid arteries (CCA), and vagus nerves in mice and the acute cerebral ischemia-reperfusion experiment in rats.Results: Compared with the blank and solvent control groups, the borneol low-; medium-; and high-dose groups can significantly prolong the gasping time of mice after decapitation, and extend the survival time of mice after ligation of bilateral CCA, and vagus nerves.Conclusion: Compared with the Xueshuantong injection group, the prolongation of survival time of mice after ligation of bilateral CCA, and vagus nerves was more apparent in the high-dose borneol experimental group; each experimental group can significantly reduce the number of leukocyte infiltration, the number of ICAM-1-positive vessels, as well as the number of TNF-α-positive cells.Conclusion: Borneol has an anti-cerebral ischemia effect.Key words: borneol; cerebral ischemia-reperfusion; IL-1β, TNF-α; ICAM-

    The establishment of the coordination relationship in green supply chain

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    2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Design of three-dimensional fitted garment pieces in a virtual environment

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    2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Cassiterite oxygen isotopes in magmatic-hydrothermal systems: in situ microanalysis, fractionation factor, and applications

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    Tin and tungsten are important metals for the industrializing society. Deciphering the origin and evolution of hydrothermal fluids responsible for their formation is critical to underpin genetic models of ore formation. Traditional approaches obtain isotopic information mainly from bulk analysis of both ore and gangue minerals, or less frequently from in situ analysis of gangue minerals, which either bear inherited complexities and uncertainties or are indirect constraints. Hence, directly obtaining isotopic information from ore minerals such as cassiterite by in situ techniques is warranted. However, this has been hampered by challenges from both analytical and applicational aspects. In this study, we first demonstrate a lack of crystallographic orientation effects during cassiterite ion microprobe oxygen isotope analysis. Along with our newly developed matrix-matched reference material, the Yongde-Cst, which has a recommended δ18O value of 1.36 ± 0.16‰ (VSMOW) as defined by gas source isotope ratio mass spectrometry, in situ oxygen isotope analysis of cassiterite now is possible. We further refine the oxygen isotope fractionation (1000 ln α) for quartz-cassiterite by first-principles calculations, which is given by the equation of 1.259 × 106/T2 + 8.15 × 103/T − 4.72 (T is temperature in Kelvin). The 1000 ln α for quartz-cassiterite has a sensitive response to temperature, and makes cassiterite-quartz an excellent mineral pair in oxygen isotope thermometry, as described by the equation of T (℃) = 2427 × (δ18Oqtz − δ18Ocst)−0.4326 − 492.4. Using the well-established 1000 ln α of quartz-water, 1000 ln α of cassiterite-water is derived as 2.941 × 106/T2 − 11.45 × 103/T + 4.72 (T in Kelvin), which shows a weak response to temperature. This makes cassiterite an ideal mineral from which to derive δ18O of fluids as robust temperature estimates are no longer a prerequisite. We have applied oxygen isotope analysis to cassiterite samples from six Sn(-W) deposits in China. The results show considerable variability in δ18O values both within a single deposit and among studied deposits. Combining the δ18O of cassiterite samples and the equilibrium oxygen isotope fractionation, we find that the δ18O values of ore-forming fluids show a strong magmatic affinity with variable but mostly no to low degree involvements (~0-10%) of meteoric water, hence our results invite a reassessment on the extent and role of meteoric water in Sn-W mineralization. This study demonstrates that in situ oxygen isotope analysis of cassiterite is a promising tool to refine sources of ore-forming fluids, and to decode hydrothermal dynamics controlling tin and tungsten mineralization

    Exploring neurotransmitters and their receptors for breast cancer prevention and treatment

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    While psychological factors have long been linked to breast cancer pathogenesis and outcomes, accumulating evidence is revealing how the nervous system contributes to breast cancer development, progression, and treatment resistance. Central to the psychological-neurological nexus are interactions between neurotransmitters and their receptors expressed on breast cancer cells and other types of cells in the tumor microenvironment, which activate various intracellular signaling pathways. Importantly, the manipulation of these interactions is emerging as a potential avenue for breast cancer prevention and treatment. However, an important caveat is that the same neurotransmitter can exert multiple and sometimes opposing effects. In addition, certain neurotransmitters can be produced and secreted by non-neuronal cells including breast cancer cells that similarly activate intracellular signaling upon binding to their receptors. In this review we dissect the evidence for the emerging paradigm linking neurotransmitters and their receptors with breast cancer. Foremost, we explore the intricacies of such neurotransmitter-receptor interactions, including those that impinge on other cellular components of the tumor microenvironment, such as endothelial cells and immune cells. Moreover, we discuss findings where clinical agents used to treat neurological and/or psychological disorders have exhibited preventive/therapeutic effects against breast cancer in either associative or pre-clinical studies. Further, we elaborate on the current progress to identify druggable components of the psychological-neurological nexus that can be exploited for the prevention and treatment of breast cancer as well as other tumor types. We also provide our perspectives regarding future challenges in this field where multidisciplinary cooperation is a paramount requirement

    Genetic diversity among Toxoplasma gondii isolates from different hosts and geographical locations revealed by analysis of ROP13 gene sequences

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    Toxoplasma gondii can infect almost all the warm-blooded animals and human beings, causing serious public health problems and economic losses worldwide. Rhoptry protein 13 (ROP13) plays some roles in the invasion process of T. gondii. In this study, sequence variation in ROP13 gene among 14 T. gondii isolates from different geographical locations and hosts was examined. The ROP13 gene was amplified from individual isolates and sequenced. Results show that the length of the ROP13 sequences was 1203 bp. In total, there were 44 variable nucleotide positions in the ROP13 sequences, and sequence variations were 0.1 to 2.0% among the 14 examined T. gondii isolates, representing higher rate in transversion than in transition. Intra-specific nucleotide variations were mainly at the second codon positions. Phylogenetic analysis of the 14 examined T. gondii isolates indicate that the ROP13 sequence was not a suitable genetic marker to differentiate T. gondii isolates of different genotypes from different hosts and geographical regions. Low variation in ROP13 gene sequence may suggest that ROP13 gene could represent a good vaccine candidate against toxoplasmosis.Key words: Toxoplasma gondii, toxoplasmosis, rhpotry protein 13 (ROP13), sequence variation, phylogenetic analysis

    Sequence variation in TgROP7 gene among Toxoplasma gondii isolates from different hosts and geographical regions

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    Toxoplasma gondii can infect a wide range of hosts including mammals and birds, causing toxoplasmosis which is one of the most common parasitic zoonoses worldwide. The present study examined sequence variation in rhoptry 7 (ROP7) gene among different T. gondii isolates from different hosts and geographical localities. Phylogenetic analysis of the examined T. gondii isolates was conducted using the maximum likelihood (ML) method. Sequence analysis revealed that 60 nucleotide positions were variable in the ROP7 gene sequences among the 19 examined T. gondii isolates, corresponding to sequence variations of 0 to 1.7%, which occurred at the first, second and third codons. Phylogenetic analysis indicated that sequence variation in ROP7 gene was low among the examined T. gondii isolates from different hosts and geographical localities, and that the ROP7 sequence was not suitable as genetic marker for the differentiation of T. gondii isolates. The results of the present study suggest that ROP7 gene may be a suitable vaccine candidate.Key words: Sequence variation, rhoptry 7 (ROP7) gene, Toxoplasma gondii, toxoplasmosis, phylogenetic analysis

    绿色生产的成本效益 : SMP案例分析

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    2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Next generation sequencing has lower sequence coverage and poorer SNP-detection capability in the regulatory regions

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    The rapid development of next generation sequencing (NGS) technology provides a new chance to extend the scale and resolution of genomic research. How to efficiently map millions of short reads to the reference genome and how to make accurate SNP calls are two major challenges in taking full advantage of NGS. In this article, we reviewed the current software tools for mapping and SNP calling, and evaluated their performance on samples from The Cancer Genome Atlas (TCGA) project. We found that BWA and Bowtie are better than the other alignment tools in comprehensive performance for Illumina platform, while NovoalignCS showed the best overall performance for SOLiD. Furthermore, we showed that next-generation sequencing platform has significantly lower coverage and poorer SNP-calling performance in the CpG islands, promoter and 5′-UTR regions of the genome. NGS experiments targeting for these regions should have higher sequencing depth than the normal genomic region
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