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871.
Tim Kröger Stephan Pannier Michael Kaliske Inga Altrogge Wolfgang Graf Tobias Preusser 《Computer methods in biomechanics and biomedical engineering》2013,16(3):431-440
In this paper, a numerical procedure to determine an optimal applicator placement for hepatic radiofrequency ablation incorporating uncertain material parameters is presented. The main focus is set on the treatment of subjective and rare data-based information. For this purpose, we employ the theory of fuzzy sets and model uncertain parameters as fuzzy quantities. While fuzzy modelling has been established in structural engineering in the recent past, it is novel in biomedical engineering. Incorporating fuzzy quantities within an optimisation task is basically innovative. In our context, fuzzy modelling allows us to determine an optimal applicator placement that maximises the therapy success under the given uncertainty conditions. The applicability of our method is demonstrated by means of an example case. 相似文献
872.
柚树(Citrus grandis)叶片光合作用对补增UV-B辐射的响应 总被引:4,自引:0,他引:4
生长在人工光照 4 0 0μmol m- 2 s- 1 下的柚树幼树光合速率的最大值为 1 0 .2± 0 .5μmol m- 2 s- 1 ;而补增UV-B辐射 ( 3.8-4 .2μW cm- 2 ,2 4 5~ 2 97nm,4 5d)的叶片则为 6.4± 0 .8μmol m- 2 s- 1 ,较对照植株降低37.2 %。对照植物的表观量子产率 (固定 mol CO2 mol- 1量子 )为 0 .0 75± 0 .0 1 2 ,而经 UV-B辐射处理植株则为0 .0 4 1± 0 .0 0 8,明显较对照植株低。UV-B辐射处理使植株叶片的光呼吸和不包括光呼吸的 CO2 补偿点增高。对照植株叶片的最大值的 CO2 羧化速率 (μmol m- 2 s- 1 )为 57.1± 1 .5μmol m- 2 s- 1 ,较 UV-B辐射处理的高30 .9% ,而 UV-B辐射处理的植株的光合电子传递速率较对照低 30 %。同时 UV-B辐射植株叶片有较低的光能转化效率 ,其较对照低 39.1 % ,叶片亦含有较低的叶绿素含量。结果表明 ,UV-B辐射明显抑制叶片光合羧化速率和光合电子传递速率 ,UV-B辐射可能抑制包括 Rubisco羧化作用在内的多个光合生理过程 ,降低叶片光合速率。柚树叶片对 UV-B辐射敏感 ,选育抗 UV-B辐射的柚树品种势在必行。 相似文献
873.
The physicochemical characteristics of the green fluorescent protein (GFP), including the thermodynamic properties (entropy, enthalpy, Gibbs' free energy, heat capacity), normal mode vibrations, and atomic fluctuations, were investigated. The Gaussian 03 computational chemistry program was employed for normal mode analysis using the AMBER force field. The thermodynamic parameters and atomic fluctuations were then calculated from the vibrational eigenvalues (frequencies) and eigenvectors. The regions of highest rigidity were shown to be the beta-sheet barrel with the central alpha-helix, which bears the chromophore. The most flexible parts of the GFP molecule were the outlying loops that cover the top and bottom of the beta-barrel. This way, the balance between rigidity and flexibility is maintained, which is the optimal relationship for protein stability in terms of Gibbs' free energy. This dual-schemed structure satisfies the requirements for GFP function. In this sense, the structure of GFP resembles a nanoscale drum: a stiff cylinder with flexible vibrating end(s). 相似文献
874.
The cis effects of phosphine, arsine and stibine ligands have been evaluated by measuring the IR stretching frequency in dichloromethane of the carbonyl ligand in a series of Rh(I) Vaska-type complexes, trans-[RhCl(CO)(L)2]. These data were correlated with those obtained by Tolman for the electronic trans influences in the [Ni(L)(CO)3] complexes. The electronic contribution, χFc, of ferrocenyl was determined as 0.8 from these plots by evaluating PPh2Fc as ligand. In order to accommodate arsine and stibine ligands an additional correction term, to compensate for differences in the donor atom, was added to Tolman’s equation for calculation of the Tolman electronic parameter of phosphine ligands. In the resulting equation: ν(CONi)=2056.1+∑i=13χi+CL values for CL of CP=0, CAs=−1.5 and CSb=−3.1 are suggested for phosphine, arsine and stibine ligands, respectively. The crystal and molecular structures of trans-[RhCl(CO)(PPh2Fc)2] · 2C6H6, trans-[RhCl(CO){P(NMe2)3}2] and trans-[RhCl(CO)(AsPh3)2] are reported. The Tolman cone angles for PPh2Fc and P(NMe2)3 were determined as 169° and 166°, while the effective cone angles for PPh2Fc, P(NMe2)3 and AsPh3 were determined as 171°, 168° and 147°, respectively. 相似文献
875.
服用CH-1双歧杆菌制剂对I型糖尿病患者、Ⅱ型糖尿病患者以及透析患者肠内细菌群以及生化指标影响的研究 总被引:1,自引:0,他引:1
随机抽取 型、 型糖尿病以及透析患者各 10例进行 CH- 1双歧杆菌制剂服用试验。并对前述患者服用 CH - 1双歧杆菌制剂的肠内细菌群和肠内腐败物质以及生化指标进行检测分析。 型糖尿病患者服用期间 ,双歧杆菌数占肠内总菌数的百分率由 (0 .84± 0 .75 )‰升高到服用 14 d后的 (7.2 5± 7.4 9)‰ ,差异有显著性。腐败菌数亦显著下降 ,卵磷脂酶阳性腐败梭菌由 8.14± 0 .37下降到服用 14 d后的 6 .0 9±0 .4 9(差异有十分显著性 )。 型糖尿病患者服用期间 ,双歧杆菌数占肠内总菌数的百分率由 (2 .4 0±3.18)‰升高到服用 14 d后的 (5 .5 6± 7.4 8)‰ ,差异有显著性。腐败菌数亦显著下降 ,卵膦脂酶阳性腐败梭菌由 7.99± 1.15下降到服用 14 d后的 5 .93± 0 .17(差异有十分显著性 )。透析患者患者服用期间 ,双歧杆菌数占肠内总菌数的百分率由 (0 .6 78± 0 .92 )‰升高到服用 14 d后的 (7.0 8± 6 .95 )‰ ,差异有显著性。腐败菌数亦显著下降 ,卵膦脂酶阳性腐败梭菌由 8.33± 0 .5 0下降到服用 14 d后的 5 .96± 0 .4 4 (差异有十分显著性 )。服用 CH- 1双歧杆菌制剂后粪便中腐败物质含量的变化 , 型糖尿病患者服用 CH- 1双歧杆菌制剂后 ,氨由 82 3± 76 .2 (μg/ g)下降到服用 14 d后的 4 71± 73.0 , 相似文献
876.
Ⅰ、Ⅱ型糖尿病和透析患者的肠道内环境与生化指标的比较研究 总被引:1,自引:0,他引:1
对Ⅰ、Ⅱ型糖尿病及透析患者的肠道内环境和血液指标进行了比较观察.肠内细菌群的检测采用光冈复合式法;氨和硫化物的测定,采用Terada的方法;吲哚及臭素等的测定方法采用同吉原方法.临床主要生化指标观察方法,采用美国康宁644电解质分析仪和美国RA-1000全自动生化分析仪.随机选取住院的Ⅰ、Ⅱ型糖尿病以及透析患者各10名对肠道内环境以及血离子、肾功能进行检测分析.结果表明:(1)肠内细菌群变化:Ⅰ型糖尿病患者,双歧杆菌数为7.73±0.44(log CFU/g),占肠内总菌数的百分率为(0.84±0.75)‰.腐败菌数亦为8.14±0.37.Ⅱ型糖尿病患者,双歧杆菌数为7.88±0.34(log CFU/g),占肠内总菌数的百分率为(2.40±3.18)‰.腐败菌数亦为7.99±1.15.透析患者,双歧杆菌数为7.76±0.42(log CFU/g),占肠内总菌数的百分率为(0.78±0.92)‰.腐败菌数亦为8.33±0.50.并检测到绿脓杆菌,其检出率为40%.(2)腐败物质的变化:Ⅰ型糖尿病患者粪便中氨为823±67.2(μg/g);硫化物为50.7±16.0;粪便中苯、甲酚、吲哚、粪臭素等的变化,吲哚、粪臭素分别为57.1±12.1、53.5±11.2(μg/g).Ⅱ糖尿病患者粪便中氨为759.9±62.9(μg/g);硫化物为30±8.3.吲哚、粪臭素分别为40.1±9.9、36.5±9.1(μg/g).透析患者粪便中的氨为1 006.6±164.9(μg/g);硫化物为80±9.9.吲哚、粪臭素分别为78.7±9.7、77.9±10.1(μg/g).(3)血清无机离子的检测结果:Ⅱ型糖尿病人的肾功、尿素、肌酐,尿素、肌酐、尿酸结果在正常范围内,肾脏无实质性损伤,但结果为正常值的上限,尿素:5.24±2.11(mmol/L),肌酐:93.8±6.15(μmol/L),尿酸:0.27±0.04(mmol/L),有肾损伤的可能.Ⅰ型糖尿病人的肾脏已有轻度的实质性损害,尿素:7.75±2.29(mmol/L),肌酐:120.1±62.91(μmol/L),尿酸:0.29±0.04(mmol/L).透析病人的肾脏已严重实质性损伤,尿素:44.2±10.50(mmol/L),肌酐:702.32±164.98(μmol/L),尿酸:0.43±0.13(mmol/L). 相似文献
877.
Jesus G.
García‐Olivares Ernesto
López‐Salinas Javier
Cumpián‐Gutiérrez Miguel A.
Cantú‐Almaguer Francisco
Zavala‐García Netzahualcoyotl
Mayek‐Pérez 《Journal of Phytopathology》2012,160(2):98-105
Charcoal rot (Macrophomina phaseolina) is a major disease of beans (Phaseolus vulgaris L.) in Mexico. The use of germplasm combining high‐yield stability with resistance to drought and charcoal rot could reduce damage from this disease. In this study, we compared the Eberhart and Russell method and the Additive Main Effect and Multiplicative Interaction (AMMI) model plus biplot analysis for measuring grain yield (GY) and charcoal rot resistance (CHRR) stabilities in 98 F8 : 10 recombinant inbred lines (RILs) derived from a cross between bean adapted to the tropics (BAT) 477 (resistant) × Pinto UI‐114 (susceptible). Experiments were conducted from 2007 to 2009 in Isla, Cotaxtla, Río Bravo and Díaz Ordaz, México, under irrigated or terminal drought conditions. anova detected significant differences (P ≤ 0.05) in GY and CHRR among environments, genotypes and genotype × environment interactions (GEI). Most RILs showed good responses to unfavourable environments based on GY (48) and CHRR (40). AMMI anova s for both traits showed that all sources of variation in the model accounted for approximately 49% of the total squared sum. For the first principal component (PC1), we found 13 RILs that were stable for GY, and for the second (PC2), we found 9 that were stable for GI. For CHRR, we detected 14 stable RILs (PC1) and eight (PC2). Biplot analysis showed the largest vectors for Díaz Ordaz (irrigated and drought, 2008), where the highest and most variable GYs were detected. The shortest vectors were found in Isla (drought, 2007) and Río Bravo (irrigated and drought, 2008), where the lowest and least variable GY were found. We found differential responses of RILs to locations, years and soil humidity conditions as well as significant GEI based on GY and CHRR. The two methods were complementary, and both gave us information to select stable, high‐yield germplasm associated with resistance to charcoal rot disease. 相似文献
878.
目的:探讨肝癌组织中微小RNA-338-3p(miR-338-3p)的表达及与临床病理参数的关系。方法:选取2015年1月至2016年6月我院手术获得的67例肝癌组织标本,同时每例标本均取癌旁正常组织标本作为配对对照,采用实时定量逆转录聚合酶链反应(RT-qPCR)对两组组织标本中的miR-338-3p进行检测,并分析其与肝癌临床病理特征的关系。结果:45例(67.16%)miR-338-3p表达下调,22例(32.85%)表达上调;RT-qPCR结果显示,肝癌组织中miR-338-3p的相对含量为(0.76±0.38),低于癌旁正常组织中的(1.23±0.45),差异有统计学意义(t=-6.259,P=0.000)。miR-338-3p在低分化、TNM分期Ⅲ+Ⅳ期、肿瘤浸润深度T3+T4期、有淋巴结转移肝癌患者肝癌组织中的表达下调率高于中高分化、Ⅰ+Ⅱ期、T1+T2期、无淋巴结转移肝癌患者,差异有统计学意义(P0.05)。不同性别、年龄、病理类型、肿瘤大小肝癌患者肝癌组织中miR-338-3p表达下调率差异无统计学意义(P0.05)。结论:miR-338-3P在肝癌组织中呈低表达水平,与分化程度、TNM分期、肿瘤浸润深度、淋巴结转移有关,可能参与了肝癌的发生发展过程,早期检测可作为评估肝癌病情的指标。 相似文献
879.
Summary In a solution culture study the absorption of Ca in the shoot of cucumber (Cucumis sativus L.) and various root parameters viz fresh weight, dry weight, length and surface area were measured at weekly intervals. All the root parameters were significantly correlated (p=0.01) with the amount of Ca absorbed when the concentration of Ca was such (5 meq/l) that the absorption capacity of the root membrane was fully saturated. The use of this relationship has been suggested in estimating the amount of roots developed in the soil system where identical conditions exist with respect to Ca concentration. Such estimated values have been termed as equivalent root length or equivalent root surface area as the case may be. P and K flux into the roots growing in the soil system have been worked out from these estimates of root parameters. 相似文献
880.
Bilass Zongo Frdric Zongo Adjima Thiombiano Joseph I. Boussim 《Journal of phycology》2019,55(4):789-800
Anthropogenic and climatic factors are important determinants of algal distribution in aquatic systems. This study aimed to identify temporary pond‐groups of phytoplankton assemblages and to establish the interactions between environmental variables and phytoplankton structure. Phytoplankton samples were collected and preserved with 5% formalin; water samples for chemical analysis were taken in August and September 2007, 2008, and 2009 in 86 ponds randomly selected in the Sahelian sector and the Sudanian sector (protected and unprotected areas) of Burkina Faso. Plankton species were examined using light microscopy and identified using standard methods. A Fuchs‐Rosenthal chamber was used for algal cell counting. NMDS ordination, indicator species analysis and canonical analysis were performed using Pc‐Ord and CANOCO. Kruskal–Wallis and Mann–Whitney U‐tests using the software Statistica were performed to compare parameters between pond‐groups. Three pond‐groups were identified: the Sahelian pond‐group, dominated by Lyngbya martensiana and Pseudanabaena constricta; the protected area pond‐group, dominated by Euglena caudata and Trachelomonas raciborskii; and the unprotected area pond‐group, dominated by Closterium venus and Euglena proxima. At P < 0.05, species composition and abundance in algal groups were mostly associated with nitrate, pH, dissolved oxygen, and conductivity. The Sahelian and the Sudanian sectors were different in pH, water transparency, and species richness. Univariate and multivariate analyses illustrate that variations in the physicochemical properties of water and algal structure followed climatic and anthropogenic gradients. The classification of ponds into algal associations demonstrated that algal assemblages may be used as reliable indicators of habitat conditions. 相似文献