5,429 research outputs found
Human settlement of the last glaciation on the Tibetan plateau
An archaeological site with 19 handprints and footprints of Homo sapiens and the remnant of a fireplace have been found on hot spring travertine at an elevation of 4200 m on the Tibetan plateau. The prints were pressed on soft travertine by humans. The age of the prints and fireplace is estimated to be around 20,000 years using the optically stimulated luminescence method. The result suggests that humans came to the plateau much earlier than was previously thought. This evidence of human settlement implies that the Tibetans occupy high plateau much earlier than the Andeans and the ice sheet did not cover the entire Tibetan plateau during the Last Glacial Maximum.published_or_final_versio
A study on the association of the chromosome 12p13 locus with sporadic late-onset alzheimer's disease in Chinese
Recent linkage and association studies have implicated the chromosome 12p13 locus as possibly harboring genetic variants predisposed to Alzheimer's disease (AD). We attempted to replicate this association in a Chinese data set comprised of 256 AD cases and 264 age-matched normal controls. A total of 14 single nucleotide polymorphisms (SNPs) were examined. Single marker association revealed the two SNPs in NCAPD2 (rs7311174 and rs2072374) as showing nominal significant p values (p = 0.0491 and 0.0116, respectively). Haplotype analysis found LD block one to be significantly associated with AD (global p = 0.0250). Haplotypes CGGATG and CAGTCG were also significantly associated with AD (p = 0.0498 and p = 0.0482, respectively). These genetic analyses provide evidence that the chromosome 12p13 locus is associated with AD in Chinese. © 2009 S. Karger AG, Basel.postprin
A knowledge-based weighting framework to boost the power of genome-wide association studies
Background: We are moving to second-wave analysis of genome-wide association studies (GWAS), characterized by comprehensive bioinformatical and statistical evaluation of genetic associations. Existing biological knowledge is very valuable for GWAS, which may help improve their detection power particularly for disease susceptibility loci of moderate effect size. However, a challenging question is how to utilize available resources that are very heterogeneous to quantitatively evaluate the statistic significances. Methodology/Principal Findings: We present a novel knowledge-based weighting framework to boost power of the GWAS and insightfully strengthen their explorative performance for follow-up replication and deep sequencing. Built upon diverse integrated biological knowledge, this framework directly models both the prior functional information and the association significances emerging from GWAS to optimally highlight single nucleotide polymorphisms (SNPs) for subsequent replication. In the theoretical calculation and computer simulation, it shows great potential to achieve extra over 15% power to identify an association signal of moderate strength or to use hundreds of whole-genome subjects fewer to approach similar power. In a case study on late-onset Alzheimer disease (LOAD) for a proof of principle, it highlighted some genes, which showed positive association with LOAD in previous independent studies, and two important LOAD related pathways. These genes and pathways could be originally ignored due to involved SNPs only having moderate association significance. Conclusions/Significance: With user-friendly implementation in an open-source Java package, this powerful framework will provide an important complementary solution to identify more true susceptibility loci with modest or even small effect size in current GWAS for complex diseases. © 2010 Li et al.published_or_final_versio
Vibration suppression in high-speed trains with negative stiffness dampers
Copyright © 2018 Techno-Press, Ltd. This work proposes and investigates re-centering negative stiffness dampers (NSDs) for vibration suppression in high-speed trains. The merit of the negative stiffness feature is demonstrated by active controllers on a high-speed train. This merit inspires the replacement of active controllers with re-centering NSDs, which are more reliable and robust than active controllers. The proposed damper design consists of a passive magnetic negative stiffness spring and a semi-active positioning shaft for re-centering function. The former produces negative stiffness control forces, and the latter prevents the amplification of quasi-static spring deflection. Numerical investigations verify that the proposed re-centering NSD can improve ride comfort significantly without amplifying spring deflection
Study on anti-atherosclerotic effect of suxiao jiuxin pill and its mechanism.
Background: Suxiao Jiuxin Pill is composed of Ligusticum wallichii, Borneolum Syntheticum and other drugs; it has qi promoting and blood circulation activating, meridian dredging and pain relieving efficacies. The objective of this paper is to study the effect of Suxiao Jiuxin Pill (quick-acting heart reliever), in atherosclerosis (AS) rat model and explore the mechanism for its prevention and treatment of AS.Materials and Methods: AS rat model was established by high cholesterol diet and single intra-peritoneal injection of increased dose of vitamin D3.Results: Compared with the model group, Suxiao Jiuxin Pill medium- and high-dose groups and atorvastatin group can effectively regulate lipid metabolism.Conclusion: We conclude that Suxiao Jiuxin Pill has a good hypo-lipidemic effect, and can inhibit the occurrence and development of AS.Keywords : Suxiao Jiuxin Pill; atherosclerosis; atorvastati
Anticancer Activity of Linalool Terpenoid: Apoptosis Induction and Cell Cycle Arrest in Prostate Cancer Cells
Purpose: To evaluate the anticancer activity of linalool against human prostate cancer (DU145) cells.Methods: The anticancer activity of linalool against DU145 cancer cells was evaluated by 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry, using propidium iodide and Annexin V-FITC, was applied to study apoptosis and cell cycle phase distribution. Inverted light microscopy was used to study the effect of linalool on cell morphology and apoptotic body formation in DU145 cells while gel electrophoresis was employed to evaluate the effect of linalool on DNA fragmentation.Results: Linalool induced a dose-dependent as well as time-dependent growth inhibitory effect on DU145 prostate cancer cells. It induced sub-G1 phase growth arrest which led to increase in sub-G0/G1 cell population after treatment with increasing doses of linalool. DNA ladder appeared to be more evident with increasing linalool concentration. However, no DNA fragments were observed in the control groups. It was observed that 4.36, 11.54, 21.88 and 15.54 % of the cells underwent early apoptosis after treatment with 0 (no linalool treatment), 20, 40, and 80 μM of linalool, respectively. Compared to control cells, linalool treatment resulted in the appearance of cell shrinkage along with membrane blebbing which are characteristic features of cell apoptosis.Conclusion: The findings of this study indicate that linalool can be developed as a plant-based chemotherapeutic agent against prostate cancerKeywords: Prostate cancer, Linalool, Chemotherapy, Cell cycle, Apoptosis, DNA fragmentation, Sub- G1 phase growt
Irradiation-induced molecular dipole reorientation in inverted polymer solar cell using small molecular electron collection layer
Inverted polymer solar cell is developed using small molecular tris(8-hydroxyquinolinato) aluminum (Alq3) as an electron collection layer between the active layer and indium-tin-oxide bottom cathode. Upon post-processing light irradiation by simulated solar illumination, the open-circuit voltage of the inverted device increases from 0.52 V to 0.60 V, resulting in the enhancement of the power conversion efficiency from 2.54 to 3.33 with negligible change in the short-circuit current. The performance improvement is attributed to the removal of surface potential due to irradiation-induced molecular dipole reorientation in the Alq3 layer, which reduces the charge transport barrier and improves the charge collection efficiency. © 2011 American Institute of Physics
Comparison of fatty-acid-binding protein 4 and adiponectin levels in infrapatellar fat pad and subcutaneous adipose tissue, synovial fluid and plasma in subjects with knee osteoarthritis
Conference Theme: Defying the Aging Spine: Our Mission ContinuesConcurrent Free Papers 2 - Basic Science/General Orthopaedics: no. 2.8Introduction: It was recently reported that inflammation is involved in the pathogenesis of osteoarthritis (OA). Fattyacid-binding
protein 4 (FABP4) and adiponectin are both adipocyte-derived cytokines closely related with inflammation
pathways. The FABP4 exhibits a pro-inflammatory property while adiponectin shows anti-inflammatory effect. The study
aimed to assess the expression of FABP4 and adiponectin in paired blood and synovial fluid from OA patients, and to
examine whether the infrapatellar fat pad (IPFP) from OA subjects would release FABP4 and adiponectin similar to that of
donor-matched subcutaneous adipose tissue (ScAT).
Materials and Methods: Plasma, synovial fluid, ScAT, and IPFP of 20 OA patients (4 males and 16 females) were collected
during total knee arthroplasty. Levels of FABP4 and adiponectin were measured in plasma, synovial fluid, and fat
conditioned media using ELISA (AIS, HKU).
Results: Levels of FABP4 were significantly higher in IPFP media than ScAT (p = 0.015), while the same were significantly
higher in synovial fluid than in plasma (p < 0.001). There were no significant differences of adiponectin levels between
IPFP and ScAT media (p = 0.737). Plasma levels of adiponectin were significantly higher than synovial fluid (p < 0.001).
Discussion and Conclusion: The OA patients exhibit an inflammatory state in local environment (IPFP and synovial fluid)
compared with systemic environment (ScAT and plasma). The IPFP may play a key role in OA inflammation and may be
an important resource of inflammatory mediators in synovial fluid.postprin
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