| 1. |
- Richards, Stephen, et al.
(författare)
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The genome of the model beetle and pest Tribolium castaneum.
- 2008
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Ingår i: Nature. - 1476-4687. ; 452:7190, s. 949-55
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Tidskriftsartikel (refereegranskat)abstract
- Tribolium castaneum is a representative of earth’s most numerous eukaryotic order, a powerful model organism for the study of generalized insect development, and also an important pest of stored agricultural products. We describe its genome sequence here. This omnivorous beetle has evolved an ability to interact with a diverse chemical environment as evidenced by large expansions in odorant and gustatory receptors, as well as p450 and other detoxification enzymes. Developmental patterns in Tribolium are more representative of other arthropods than those found in Drosophila, a fact represented in gene content and function. For one, Tribolium has retained more ancestral genes involved in cell-cell communication than Drosophila, and some are expressed in the growth zone crucial for axial elongation in short germ development. Systemic RNAi in T. castaneum appears to use mechanisms distinct from those found in C. elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control.
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| 2. |
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| 3. |
- Meng, Wen-Jian, et al.
(författare)
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Microsatellite instability did not predict individual survival in sporadic stage II and III rectal cancer patients
- 2007
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Ingår i: Oncology. - : S. Karger AG. - 0890-9091 .- 0030-2414 .- 1423-0232. ; 72:1-2, s. 82-88
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Tumors with high-frequency microsatellite instability (MSI-H) have unique biological behavior and the predictive role of microsatellite instability (MSI) status on survival of colorectal cancer is still debated. The prognostic significance of MSI status in sporadic stage II and III rectal cancer patients needs to be more precisely defined. So we investigated the relationship between MSI status and clinicopathological features and prognosis in these patients. Methods: DNAs from fresh-frozen paired samples of tumors and corresponding normal tissue from 128 stage II and III rectal cancer patients were analyzed for MSI by PCR amplification using markers recommended by a National Cancer Institute workshop on MSI. To assess prognostic significance, Cox proportional hazards modeling was used. Results: Twelve (9.3%) tumors in our study were MSI-H, 28 (21.9%) were low-frequency MSI (MSI-L) and 88 (68.8%) were microsatellite stable (MSS). Most of the MSI-H tumors compared with MSI-L and MSS tumors were found in female patients (p = 0.031), had mucinous histology (p = 0.023), high grade of differentiation (p = 0.002) and high level of preoperative serum carcinoembryonic antigen (p = 0.005). Rectal cancer patients with MSI-H did not show a better clinical outcome than those with MSI-L/MSS, neither in all cases (p = 0.986) nor in stage II and stage III disease analyzed separately (p = 0.705 and p = 0.664, respectively). Conclusions: Data provided here demonstrated there was high incidence of MSI-H and MSI was not a prognostic factor in sporadic stage II and III rectal cancers from the Chinese Han population included in this study. Tumor stage is more suitable than MSI status for prediction of individual survival in sporadic stage II and III rectal cancer patients. Copyright © 2007 S. Karger AG.
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| 4. |
- Meng, Wen-Jian, et al.
(författare)
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Novel mutations and sequence variants in exons 3-9 of human T Cell Factor-4 gene in sporadic rectal cancer patients stratified by microsatellite instability
- 2007
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Ingår i: World Journal of Gastroenterology. - 1007-9327 .- 2219-2840. ; 13:27, s. 3747-3751
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To establish the role of human T Cell Factor-4 (hTCF-4) gene exons 3-9 mutation status in association with sporadic rectal cancer with microsatellite instability (MSI). Methods: Microsatellite markers were genotyped in 93 sporadic rectal cancer patients. Eleven cases were found to be high-frequency MSI (MSI-H). Sequence analysis of the coding region of the exons 3-9 of hTCF-4 gene was carried out for the 11 MSI-H cases and 10 controls (5 microsatellite stability (MSS) cases and 5 cases with normal mucosa). The sequencing and MSI identification were used. Results: Several novel mutations and variants were revealed. In exon 4, one is a 4-position continuous alteration which caused amino acid change from Q131T and S132I (391insA, 392 G > A, 393 A > G and 395delC) and another nucleotide deletion (395delC) is present in MSI-H cases (5/10 and 4/10, respectively) but completely absent in the controls. Conclusion: Novel mutations in exon 4 of hTCF-4 gene were revealed in this study, which might be of importance in the pathogenesis of sporadic rectal cancer patients with MSI-H. © 2007 WJG. All rights reserved.
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| 5. |
- Wang, Sheng-Jun, 1981-, et al.
(författare)
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Influence of synaptic interaction on firing synchronization and spike death in excitatory neuronal networks
- 2008
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Ingår i: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics. - New York : American Physical Society through the American Institute of Physics. - 1063-651X .- 1095-3787. ; 78:6, s. 061906-
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the influence of efficacy of synaptic interaction on firing synchronization in excitatoryneuronal networks. We find spike death phenomena: namely, the state of neurons transits from the limit cycleto a fixed point or transient state. The phenomena occur under the perturbation of an excitatory synapticinteraction, which has a high efficacy. We show that the decrease of synaptic current results in spike deaththrough depressing the feedback of the sodium ionic current. In the networks with the spike death property thedegree of synchronization is lower and insensitive to the heterogeneity of neurons. The mechanism of theinfluence is that the transition of the neuron state disrupts the adjustment of the rhythm of the neuronsoscillation and prevents a further increase of the firing synchronization.
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| 6. |
- Xu, Bing, et al.
(författare)
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Clinicopathological significance of caspase-8 and caspase-10 expression in rectal cancer
- 2008
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Ingår i: Oncology. - : S. Karger AG. - 0890-9091 .- 0030-2414 .- 1423-0232. ; 74:3-4, s. 229-236
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the expression of caspase-8 and -10 in rectal adenoma, adenocarcinoma and the corresponding normal mucosa tissue, and to clarify the relationship between their expression and clinicopathological parameters of rectal cancer. Methods: The expression of caspase-8 and -10 was determined by real-time RT-PCR and immunohistochemistry in 36 rectal adenomas, 93 rectal cancers and 93 corresponding normal rectal mucosa samples. Results: Compared with normal mucosa, the mRNA expression of caspase-8 was higher in adenomas (p = 0.003), while that of caspase-10 was lower in adenomas (p = 0.035) and cancers (p = 0.001). Immunohistochemical results showed caspase-8 up-regulation in adenomas (p = 0.014), and caspase-10 down-regulation in adenomas (p = 0.034) and cancers (p < 0.001) compared with normal mucosa samples. Cancers with poor differentiation had lower caspase-10 mRNA and protein levels than those with better differentiation (p = 0.041 and p = 0.046, respectively). The protein expression of caspase-8 and -10 was in accordance with the mRNA expression (p = 0.043 and p = 0.018, respectively). Conclusions: Caspase-8 expression was up-regulated in rectal adenomas. Caspase-10 expression was down-regulated in both rectal adenomas and cancers, and was further related to differentiation. Caspase-8 and -10 may be involved in the pathogenesis of rectal cancer. Copyright © 2008 S. Karger AG.
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| 7. |
- Abdulghani, Saba, et al.
(författare)
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The influence of initial pressurization and cup introduction time on the depth of cement penetration in an acetabular model.
- 2007
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 78:3, s. 333-339
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Tidskriftsartikel (refereegranskat)abstract
- Background Acetabular cementation during total hip arthroplasty is considered difficult mainly due to the appearance and anatomy of the acetabulum. Improved cementation technique has been shown to improve the longevity of acetabular components. Method We designed a ceramic model to investigate the effect of varying the initial cement pressurization and cup introduction times on the depth of cement penetration. 4 groups were prepared, 2 of which involved varying initial cement pressurization and cup introduction times. Group 3 involved initial cement pressurization with no cup introduction, while group 4 involved cup introduction with no prior cement pressurization. Results and interpretation Most cement penetration occurred in the early pressurization phase, and we conclude that a relatively early and longer cement pressurization time and late cup introduction are positive factors for increased cement penetration in the acetabulum model.
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| 8. |
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| 9. |
- Camire, Christopher, et al.
(författare)
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Material characterization and in vivo behavior of silicon substituted alpha-tricalcium phosphate cement.
- 2006
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Ingår i: Journal of Biomedical Materials Research. Part B - Applied Biomaterials. - : Wiley. - 1552-4981 .- 1552-4973. ; 76B:2, s. 424-431
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Tidskriftsartikel (refereegranskat)abstract
- The possibility and biological effects of substituting silicon in a-tricalcium phosphate (alpha-TCP) by way of solid-state reaction have been evaluated. a-TCP powders with varying substitution amounts (1 and 5 mol % Ca2SiO4) were synthesized by reacting mixtures of CaCO3, Ca(2)P(2)O7, and SiO2, at a rate of 4 degrees C(min)(-1) to 1100 degrees C, left to dwell for 2 h and then heated to 1325 degrees C at 4 degrees C(min)(-1) and left to dwell for a period of 4 h. The powders were then rapidly quenched in air. Si incorporation could be verified by X-ray diffraction analysis, indicating an increase of the lattice volume with increasing Si content from 4284.1(8) to 4334(1) angstrom(3) for pure alpha-TCP and alpha-Si5%TCP, respectively. The hydrolysis of milled alpha-SiTCP powders was monitored by isothermal calorimetry, and the compressive strength of set cements was tested. The results showed changes in speed and amount of heat released during reactivity tests and a decrease in mechanical strength (60, 50, and 5 MPa) with increasing Si content. In vitro bioactivity of the set cements after soaking in simulated body fluid for 4 weeks was also tested. The formation of a bonelike apatite layer on the surface of the set cements could be observed and was thickest for 1% Si (20 mu m). These results were in good agreement with the in vivo studies performed, which showed strong evidence that the cement containing 1% silicon doped alpha-TCP enhanced mesenchymal cell differentiation and increased osteoblast activity compared with alpha-TCP. (c) 2005 Wiley Periodicals, Inc.
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| 10. |
- Cheng, Lihua, et al.
(författare)
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Design of wavelength division demultiplexers based on holographic gratings with a low polarization dependent loss
- 2006
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Ingår i: Guangzi Xuebao/Acta Photonica Sinica. - 1004-4213. ; 35:11, s. 1667-1671
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Tidskriftsartikel (refereegranskat)abstract
- An optimizing method of main structure parameters (e. g. , the thickness of the crystal) and writing conditions (e. g., the incident angle) is presented for a holographic grating wavelength division demultiplexer based on photorefractive LiNbO3 crystals. The key performance parameters of the demultiplexer, such as the loss and the polarization dependent loss (PDL), are optimized by selecting favourite structure parameters using a rigorous coupled wave analysis method. Numerical results show that a low loss and a low PDL can be achieved by using the optimal crystal thickness and incident angle. The designed demultiplexer obtains the favourite synthetical performance for an actual application. The experimental method of the grating recorded is also introduced in the present paper. The experimental results accorded with theoretical computation commendably by testing the three different specimens.
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