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121.
Interstitial photodynamic therapy (iPDT) has shown promise recently as a minimally invasive cancer treatment, partially due to the development of non‐toxic photosensitizers in the absence of activation light. However, a major challenge in iPDT is the pre‐treatment planning process that specifies the number of diffusers needed, along with their positions and allocated powers, to confine the light distribution to the target volume as much as possible. In this work, a new power allocation algorithm for cylindrical light diffusers including those that can produce customized longitudinal (tailored) emission profiles is introduced. The proposed formulation is convex to guarantee the minimum over‐dose possible on the surrounding organs‐at‐risk. The impact of varying the diffuser lengths and penetration angles on the quality of the plan is evaluated. The results of this study are demonstrated for different photosensitizers activated at different wavelengths and simulated on virtual tumors modeling virtual glioblastoma multiforme cases. Results show that manufacturable cylindrical diffusers with tailored emission profiles can significantly outperform those with conventional flat profiles with an average damage reduction on white matter of 15% to 55% and on gray matter of 23% to 58%. 相似文献
122.
Ikhlas Al‐Hadeethi Yan Li Abdul Kareem H. Odhafa Hanan Al‐Hadeethi Saman Seneweera Shu K. Lam 《Ecology and evolution》2019,9(13):7425-7437
The increasing [CO2] in the atmosphere increases crop productivity. However, grain quality of cereals and pulses are substantially decreased and consequently compromise human health. Meta‐analysis techniques were employed to investigate the effect of elevated [CO2] (e[CO2]) on protein, zinc (Zn), and iron (Fe) concentrations of major food crops (542 experimental observations from 135 studies) including wheat, rice, soybean, field peas, and corn considering different levels of water and nitrogen (N). Each crop, except soybean, had decreased protein, Zn, and Fe concentrations when grown at e[CO2] concentration (≥550 μmol/mol) compared to ambient [CO2] (a[CO2]) concentration (≤380 μmol/mol). Grain protein, Zn, and Fe concentrations were reduced under e[CO2]; however, the responses of protein, Zn, and Fe concentrations to e[CO2] were modified by water stress and N. There was an increase in Fe concentration in soybean under medium N and wet conditions but nonsignificant. The reductions in protein concentrations for wheat and rice were ~5%–10%, and the reductions in Zn and Fe concentrations were ~3%–12%. For soybean, there was a small and nonsignificant increase of 0.37% in its protein concentration under medium N and dry water, while Zn and Fe concentrations were reduced by ~2%–5%. The protein concentration of field peas decreased by 1.7%, and the reductions in Zn and Fe concentrations were ~4%–10%. The reductions in protein, Zn, and Fe concentrations of corn were ~5%–10%. Bias in the dataset was assessed using a regression test and rank correlation. The analysis indicated that there are medium levels of bias within published meta‐analysis studies of crops responses to free‐air [CO2] enrichment (FACE). However, the integration of the influence of reporting bias did not affect the significance or the direction of the [CO2] effects. 相似文献
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124.
Epidermal growth factor receptor and notch pathways participate in the tumor suppressor function of gamma-secretase 总被引:1,自引:0,他引:1
Li T Wen H Brayton C Das P Smithson LA Fauq A Fan X Crain BJ Price DL Golde TE Eberhart CG Wong PC 《The Journal of biological chemistry》2007,282(44):32264-32273
Gamma-secretase, a unique aspartyl protease, is required for the regulated intramembrane proteolysis of Notch and APP, pathways that are implicated, respectively, in the pathogenesis of cancer and Alzheimer disease. However, the mechanism whereby reduction of gamma-secretase causes tumors such as squamous cell carcinoma (SCC) remains poorly understood. Here, we demonstrate that gamma-secretase functions in epithelia as a tumor suppressor in an enzyme activity-dependent manner. Notch signaling is down-regulated and epidermal growth factor receptor (EGFR) is activated in SCC caused by genetic reduction of gamma-secretase. Moreover, the level of EGFR is inversely correlated with the level of gamma-secretase in fibroblasts, suggesting that the up-regulation of EGFR stimulates hyperproliferation in epithelia of mice with genetic reduction of gamma-secretase. Supporting this notion is our finding that the proliferative response of fibroblasts lacking gamma-secretase activity is more sensitive when challenged by either EGF or an inhibitor of EGFR as ompared with wild type cells. Interestingly, the up-regulation of EGFR is independent of Notch signaling, suggesting that the EGFR pathway functions in parallel with Notch in the tumorigenesis of SCC. Collectively, our results establish a novel mechanism linking the EGFR pathway to the tumor suppressor role of gamma-secretase and that mice with genetic reduction of gamma-secretase represent an excellent rodent model for clarifying pathogenesis of SCC and for testing therapeutic strategy to ameliorate this type of human cancer. 相似文献
125.
M. Abdul Maleque Hiroaki T. Ishii Kaoru Maeto Shingo Taniguchi 《Arthropod-Plant Interactions》2007,1(3):175-185
We evaluated the effectiveness of line thinning, a new silvicultural technique, toward restoring diversity of Coleoptera in
overstocked Cryptomeria japonica D. Don plantations in central Japan. We compared the abundance of some common Coleoptera families between line-thinned stands
and adjacent unthinned stands in two plantations: low-elevation Sugi site (4 years since thinning) and high-elevation Kuchiotani
site (6 years since thinning). Many bettle families comprising various functional groups such as plant feeders, wood borers,
rotten wood feeders, root feeders, fungus feeders, dung feeders, and scavengers were more abundant in the line-thinned stands
than in the unthinned stands. Furthermore, some important families were missing from the unthinned stands. There were strong
positive relationships between Coleopteran abundance and understory vegetation. Our results suggest that line thinning may
potentially increase biodiversity in overstocked C. japonica plantations by restoring important ecological processes such as food-web interactions (pollination, predation, herbivory,
decomposition, parasitism, etc.), and habitat conditions. 相似文献
126.
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128.
Elizabeth F. Dowler Annette Diehl Peter Schmieder Christoph Brockmann Jonathan Elkins Meera Soundararajan Hartmut Oschkinat Linda J. Ball 《Biomolecular NMR assignments》2007,1(1):95-97
We have assigned 1H, 15N and 13C resonances of the RGS domain from the human RGS14 protein, a multi-domain member of the RGS (Regulators of G-protein signalling)
family of proteins, important in the down-regulation of specific G-protein signalling pathways. 相似文献
129.
以富贵草(Pachysandra terminalis Sieb.et Zucc.)(以下简称PT)为实验材料,采用开放式浸杀法研究其植物原粉及提取物(PT-Ⅰ)对钉螺的杀灭效果和对鱼类的毒性作用。结果表明PT原粉浓度为17.5 mg/L时,钉螺72 h死亡率为93.4%,120 h死亡率达100.0%;其24、72、120、168 h的LC50分别为42.28、7.20、4.20、3.17 mg/L。PT原粉浓度为75.0 mg/L时,经168 h鱼死亡率为0。使用浓度为35.0、17.5、8.75、4.38 mg/L的PT原粉,分别浸泡1、2、18、42 h时,抑制钉螺上爬率均达到100%。原粉经提取分离得到PT-Ⅰ组分,以1.40 mg/L的PT-Ⅰ组分分别浸杀钉螺24、48、72、96、120 h,钉螺死亡率分别为36.7%、73.3%、96.7%、96.7%、100.0%。表明PT具有很好的杀灭钉螺、抑制钉螺上爬效果,且对鱼毒性较低,是一种较有研究价值的灭螺植物。 相似文献
130.
Streptoverticillium kashmirense AF1 with the ability to degrade a natural polymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was isolated from municipal sewage sludge by soil burial technique. The PHBV film was degraded by the action of extracellular enzymes secreted by the microorganisms. Degradation of PHBV was evident by the formation of clear zones of hydrolysis on the polymer containing mineral salt agar plates. The extent of PHBV degradation increased up to 30 days of incubation. Maximum production of PHBV depolymerase was observed both at pH 8 and pH 7, 45 °C, 1% substrate concentration and in the presence of lactose as an additional carbon source. Two types of extracellular PHBV depolymerases were purified fromS. kashmirense AF1 by gel permeation chromatography using Sephadex G-75. The molecular weights of the two proteins were found to be 35 and 45 kDa approximately, as determined by SDS-PAGE. The results of the Sturm test also showed more CO2 production as a result of PHBV degradation, in the test as compared to control. The present findings indicated the degradation capabilities ofS. kashmirense AF1. 相似文献