961 resultados para 12930-039


Relevância:

10.00% 10.00%

Publicador:

Resumo:

采用批量平衡方法,研究了土霉素在原土及去除有机质土壤中的吸附和解吸.结果表明,土霉素在原土和去除有机质土壤中的吸附和解吸等温线均不同程度地偏离线性模型,其中Freundlich模型可以对吸附和解吸数据进行良好的非线性拟合,在不同土壤以及不同土壤处理中的拟合相关系数(r)均达到极显著水平.去除有机质能够降低土霉素在土壤中的吸附容量(lgKf),但增加了吸附强度(1/n).土霉素在土壤上的解吸过程存在明显的滞后现象,在所设土霉素浓度范围内,土霉素在褐土和红壤中的平均滞后系数(HIa)分别为0.039和0.015;去除有机质后的褐土和红壤对土霉素的解吸滞后现象显著增强(P<0.01),其HIa分别增加到0.068和0.028.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

应用数理统计方法构建评价碳汇管理政策影响分析模型,模拟农田碳汇管理政策的影响。山东省冬小麦种植的案例研究表明,在常规耕作、秸秆还田和休耕3种政策措施两两组合构成的3种情景下,农田碳汇管理政策的绩效及农户作物种植行为存在较大差异。基于利益最大化的基本经济学假设,研究政府在采用不同碳汇管理政策措施的背景下,农民选择不同碳汇管理措施的机会成本及收益变化,模拟农民调整作物种植行为的决策过程。研究表明,利用以县(市、区)为基本单元的农业生产数据和农产品价格、农作物播种面积等数据,可以构建农田碳汇管理政策影响分析模型

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The anodic voltammetric behavior of ethambutol in the presence of various electrolytes was studied by direct-current voltammetry, differential-pluse voltammetry and cyclic voltammetry at a glassy carbon electrode. In a medium of 0.039 mol/L Na2HPO4, an oxidative peak of ethambutol was obtained. The peak potential is at about 1.04 V( vs. Ag/AgCl). The height of the peak is linearly increased with the concentration of ethambutol over the range of 3 mg/Lsimilar to1000 mg/L. The method has been used for the direct determination of ethambutol in tablets. The average recovery of ethambutol in urine samples is 84.7%. Experimental results proved that the electrode reaction was diffusion controlled and irreversible.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The reactions of [Cp2Mo2(CO)4] (1) with 2,2'-dipyridyl disulphide (C5H4NS-)2, 8,8'-diquinolyl disulphide (C9H6NS-)2 and tetramethyl thiuram disulphide (Me2NC(S)S-)2 in toluene solution resulted in the cleavage of the Mo-Mo triple bond to yield molybdenum complexes [CpMo(CO)2(C5H4NS)] (2), [CpMo(CO)2(C9H6NS)] (3) and [CpMo(CO)2(S2CNMe2)] (4), respectively. The molecular structures of 2, 3 . O=PPh3 and 4 were determined by X-ray diffraction studies. Crystals of 2 are monoclinic, space group P2(1)/n, with Z = 4, in a unit cell of dimensions a = 6.448(1), b = 12.616(2), c = 14.772(2) angstrom, beta = 92.85(1)-degrees. The structure was refined to R = 0.028 and R(w) = 0.039 for 1357 observed reflections. Crystals of 3 . O=PPh3 are triclinic, space group P1BAR, with Z = 2, in a unit cell of dimensions a = 11.351(3), b = 13.409(3), c = 9.895(2) angstrom, alpha = 94.59(2), beta = 90.35(2), gamma = 78.07(2)-degrees. The structure was refined to R = 0.033 and R(w) = 0.037 for 3260 observed reflections. Crystals of 4 are monoclinic, space group P2(1)/a and Z = 4 with a = 12.468(5), b = 7.637(2), c = 13.135(4) angstrom, beta = 96.62(3). The structure was refined to R = 0.032 and R(w) = 0.042 for 1698 observed reflections. Each of complexes 2-4 contains a cyclopentadienyl ligand, a cis pair of carbonyls and a chelate ligand (S,N donor or S,S donor). All the compounds have distorted square-pyramid structures.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

能量代谢指动物在进行生理活动(如摄食、消化以及动物的活动等)时所消耗能量的总和,一般以动物的呼吸率利排泄率来估计动物的能量代谢。其主要研究内容是闸明生物能量代谢的基木规律以及与环境闪子的关系。菲律宾蛤仔(Ruditapesphil ippmarum)是我国一种重要的养殖贝类,关于其能量代谢的研究却较少,这种状况妨碍了菲律宾蛤仔养殖生态理论的完善和养殖技术的提高。本研究主要对菲律宾蛤仔呼吸率和排泄率的基本规律(能量代谢与体重的关系、能量代谢的昼夜变化)及其与环境因子(饵料浓度、水温、栖息底质环境)的关系进行探讨。研究结果如下:1.不同体重菲律宾蛤仔代谢率小同。实验川菲律宾蛤仔分三种大小:l(干肉重为0.07-0.14g)、ll(干肉重0.27-0.34g)、III(干肉重0.45~0.63g)。温度包括:26℃(八月)、20℃(十月)、1 5℃(十二月)、9℃(一月)。实验共设四个饵料浓度:2.28±0.25,6.454±0.44,10.284±0.82,15.414±1.56mgTPM/L(TPM,总颗粒物),饵料中POM(颗粒有机物)含量都为4.68±1.64 mg/L。常温下菲律宾蛤仔代谢率随着体重的增大而增大。15℃、20~C、26℃时蛤仔呼吸率与干肉重呈明显的幂函数关系R=aW~b,a值变动范围为0.1076-0.3309;b值变动范围为0.239l~0.8381;蛤仔排泄率与干肉重也呈明显的幂函数关系N=aW~b,a值变动范围为14.213~68.362:b值变动范围为0.3673-1.1 532。9℃(饵料浓度为2.28±0.25mgTPM/L)、20℃(饵料浓度为10.284-0.82mgTPM/L)、26℃(饵料浓度为6.454±0.44mgTPM/L)时不同体重蛤仔氧氮比差异显著,其它情况下不同体重蛤仔氧氮比差异不显著。2.常温下菲律宾蛤仔代谢率受饵料浓度的影响,不同大小蛤仔受饵料浓度的影响程度不同。I组蛤仔呼吸率受饵料浓度的显著影响,II组III组蛤仔呼吸率只在9℃(一月)和26~C(八月)时受饵料浓度的显著影响。26℃时影响最显著,26℃时I组蛤仔在饵料浓度为2.28±0.25,6.45±0.44,l0.28±0.82,15.4l±1.56mgTPM/L时呼吸率分别是O.086,0.146,0.073,0.093(mlO_2/h);ll组蛤仔在上述浓度饵料中呼吸率分别是0.138,0.214,0.J 26,0.12l(mlO_2/h);III组蛤仔在上述浓度饵料中呼吸率分别是0.129,0.266,0.186,0.192(mlO_2/h)。菲律宾蛤仔呼吸率在饵料浓度为6.45±0.44 mgTPM/L时最高,蛤仔呼吸率在其它饵料浓度时都会降低。菲律宾蛤仔排泄率在饵料浓度为10.28±0.82 mgTPM/L和15.4l士1.56mgTPM/L时显著高于其它浓度组,9℃时这种趋势更明显,9℃时饵料浓度为2.28±0.25,6.454±044,lO.284±0.82,15.41±1.56mgTPM/L中I组蛤仔排泄率分别是4.297,2.874,8.003,6.658(μgNH_3-N/h);II组蛤仔在上述浓度饵料中排泄率分别是4.011,3.609,10.427,12.732(μgNH_3-N/h);III组蛤仔在上述浓度饵料中排泄率分别是2.28 l,6.452,10.283,15.417(μgNH_3-N/h)。3.菲律宾蛤仔代谢率受自然温度的显著影Ⅱ向。I组蛤仔在9℃、15℃、20℃、26℃时呼吸率平均为0.057,0.085,0.039,O.099;II组蛤仔在上述四个温度中呼吸率平均为0.08,O.128,0.089,0.149(mlO_2/h),I组和II组蛤仔在9℃和20~C时呼吸率较低,在26℃时呼吸率最高。III组蛤仔在上述四个温度中呼吸率平均为0.09,O.1 59,O.143,O.193(mlO_2/h),在9℃时llI组蛤仔呼吸率显著低于其它温度组。温度为9℃、15℃、20℃、26℃时l组蛤仔排泄率平均为5.458,13.169,4.946,11.138(μgNH_3-N/h):II组蛤仔在上述温度中排泄率平均为7.695,23.578,8.319,23.90l(μgNH_3-N/h);III组蛤仔在上述温度中排泄率平均为11.738,27.443,15.658,35.407(μgNH_3-N/h),蛤仔排泄率在15℃和26℃时均高于9℃和20℃。4.摄食状态与饥饿状态菲律宾蛤仔代谢率有明显不同。26℃时蛤仔静止状态呼吸率平均为0.336(m102/g干重.h),摄食状态呼吸率平均为0.656(ml0_2干重.h),摄食状态呼吸率比静止状态平均升高了0 32(ml0_2/g干重.h);26℃时蛤仔静止状态排泄率平均为39.471(μgNH_3-N/g干重.h),摄食状态排泄率平均为88.08(μgNH_3-N/g干重.h),摄食状态排泄率比静止状态排泄率平均升高了48.6(μgNH_3-N/g干重.h)。摄食状态代谢率平均是静止状态的2~3倍。根据摄食引起的呼吸率和排泄率升高量得出每氧化产生lμgNH_3-N需0_2量平均为7.05μl。5.人工控制温度对菲律宾蛤仔代谢率有明显影响。不同大小蛤仔受温度的影响程度不同。在温度5℃、10℃、l 5℃、20℃、26℃,I组和II组蛤仔呼吸率都随着温度的升高而升高,在10℃~l5℃和20℃~26℃这二个温度变化范围内呼吸率变化最大,在20℃~26℃时I组蛤仔呼吸率变动范围为O.85~1.04(m10_2/g干重.h)、II组蛤仔变动范围为0.57~0.86(ml0_2/g干重.h)。III组蛤仔呼吸率只在5℃~l0℃时明显增高,变动范围为0.09~0.5l(m10_2/g干重.h),在10℃~26℃范围内变化不大。I组和II组蛤仔排泄率随着温度的升高而升高,变动幅度较大,在5℃~26℃范围内其排泄率变动范围为10.32~81.53(μgNH_3-N/g干重.h);而 III组蛤仔排泄率只在5℃~15℃时随着温度的升高而升高,其排泄率变动范围为6.75~23.77(μgNH_3-N/g干重.h),在15℃~26℃范围内几乎不变。III组蛤仔的适温范围比I组和II组蛤仔广。菲律宾蛤仔在5℃和10℃时氧氮比变化明显,变动范围为2.76~11.44,在15~26℃时变化不大。6.菲律宾蛤仔代谢率有明显的日节律性,呈正弦曲线型变化。蛤仔夜问代谢率明显升高。I组蛤仔夜间呼吸率平均为0.867(m10_2/g干重.h),白天呼吸率平均为O.504(m10_2/g干重.h);II组蛤仔夜间呼吸率平均为0.438(m10_2/g干重.h),白天呼吸率平均为0.36l(m102/g干重.h);III组蛤仔夜间呼吸率平均为0.409(m10_2/g干重.h),白天呼吸率平均为0.252(m102/g干重.h)。在22:00-23:00菲律宾蛤仔呼吸率最高。7.底质环境对菲律宾蛤仔的代谢率有明显影响。在饥饿状态下菲律宾蛤仔在泥沙底质中呼吸率平均为l 406(m10_2/g干重h),在无泥沙环境中呼吸率平均为O.963(ml0_2/g干重.h);摄食状态下菲律宾蛤仔在泥沙底质中呼吸率平均为1.59l(m102/g干重.h),在无泥沙环境中呼吸率平均为1.115(m10_2/g干重.h)。在饥饿状态下菲律宾蛤仔在泥沙底质中排泄率平均为78.934(μgNH_3-N/g 干重.h),在无泥沙环境巾排泄率平均为45.043(μgNH_3-N/g干重.h);摄食状态下菲律宾蛤仔在泥沙底质中排泄率平均为87.12l(μgNH_3-N/g干重.h),在无泥沙底质中排泄率平均为58.354(μgNH_3-N/g干重.h)。蛤仔在泥沙环境中呼吸率和排泄率都明显升高。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

目的:建立反相高效液相色谱法同时测定刺芒龙胆植物不同部位落干酸、獐牙菜苦苷、龙胆苦苷的含量。方法:采用ZORBAX SB-C18(250mm×4.6mm,5μm)色谱柱,流动相为甲醇-水(含0.04%磷酸)的比例25:75,流速1mL·min^-1,检测波长238nm,柱温30℃。结果:3种成分均达到基线分离,落干酸、獐牙莱苦苷、龙胆苦苷的线性范围分别为0.039~1.56μg(r=0.9998),0.0725~1.45μg(r=0.9999),0.061~1.225μg(r=0.9997);回收率为101.3%(RSD=2.6%),98.7%(RSD=3.1%,99.6%(RSD=1.2%)。结论:测定方法快速,结果准确、可靠。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

M.A. Fortes et al., Instabilities in two-dimensional flower and chain clusters of bubbles, Colloids and Surfaces A: Physicochemical and Engineering Aspects Volume 309, Issues 1-3, 1 November 2007, Pages 64-70 A Collection of Papers Presented at the 6th Eufoam Conference, Potsdam, Germany, 2-6 July, 2006

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Davison G, Gleeson M, 2006. The effect of 2 weeks vitamin C supplementation on immunoendocrine responses to 2.5 h cycling exercise in man. European Journal of Applied Physiology 97(4): 454-461 RAE2008

Relevância:

10.00% 10.00%

Publicador:

Resumo:

44 hojas : fotografías a color.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Intrinsic and extrinsic speaker normalization methods are systematically compared using a neural network (fuzzy ARTMAP) and L1 and L2 K-Nearest Neighbor (K-NN) categorizers trained and tested on disjoint sets of speakers of the Peterson-Barney vowel database. Intrinsic methods include one nonscaled, four psychophysical scales (bark, bark with endcorrection, mel, ERB), and three log scales, each tested on four combinations of F0 , F1, F2, F3. Extrinsic methods include four speaker adaptation schemes, each combined with the 32 intrinsic methods: centroid subtraction across all frequencies (CS), centroid subtraction for each frequency (CSi), linear scale (LS), and linear transformation (LT). ARTMAP and KNN show similar trends, with K-NN performing better, but requiring about ten times as much memory. The optimal intrinsic normalization method is bark scale, or bark with endcorrection, using the differences between all frequencies (Diff All). The order of performance for the extrinsic methods is LT, CSi, LS, and CS, with fuzzy ARTMAP performing best using bark scale with Diff All; and K-NN choosing psychophysical measures for all except CSi.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This work explores the functionalization of an organic-inorganic MoS2 lamellar compound, prepared by a Chemical Liquid Deposition Method (CLD), that has an interlamellar distance of ~5.2 nm, using clusters of gold nanoparticles. The gold nanoparticles have a mean diameter of 1.2 nm, a stability of ~85 days, and a zeta potential measured to be ζ = -6.8 mV (solid). The nanoparticles are localized in the hydrophilic zones, defined by the presence of amine groups of the surfactant between the lamella of MoS2. SEM, TEM, EDAX and electron diffraction provide conclusive evidence of the interlamellar insertion of the gold nanoparticles in the MoS2.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: There is a current lack of consensus on defining metabolically healthy obesity (MHO). Limited data on dietary and lifestyle factors and MHO exist. The aim of this study is to compare the prevalence, dietary factors and lifestyle behaviours of metabolically healthy and unhealthy obese and non-obese subjects according to different metabolic health criteria. Method: Cross-sectional sample of 1,008 men and 1,039 women aged 45-74 years participated in the study. Participants were classified as obese (BMI ≥30kg/m2) and non-obese (BMI <30kg/m2). Metabolic health status was defined using five existing MH definitions based on a range of cardiometabolic abnormalities. Dietary composition and quality, food pyramid servings, physical activity, alcohol and smoking behaviours were examined. Results: The prevalence of MHO varied considerably between definitions (2.2% to 11.9%), was higher among females and generally increased with age. Agreement between MHO classifications was poor. Among the obese, prevalence of MH was 6.8% to 36.6%. Among the non-obese, prevalence of metabolically unhealthy subjects was 21.8% to 87%. Calorie intake, dietary macronutrient composition, physical activity, alcohol and smoking behaviours were similar between the metabolically healthy and unhealthy regardless of BMI. Greater compliance with food pyramid recommendations and higher dietary quality were positively associated with metabolic health in obese (OR 1.45-1.53 unadjusted model) and non-obese subjects (OR 1.37-1.39 unadjusted model), respectively. Physical activity was associated with MHO defined by insulin resistance (OR 1.87, 95% CI 1.19-2.92, p = 0.006).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The standard early markers for identifying and grading HIE severity, are not sufficient to ensure all children who would benefit from treatment are identified in a timely fashion. The aim of this thesis was to explore potential early biomarkers of HIE. Methods: To achieve this a cohort of infants with perinatal depression was prospectively recruited. All infants had cord blood samples drawn and biobanked, and were assessed with standardised neurological examination, and early continuous multi-channel EEG. Cord samples from a control cohort of healthy infants were used for comparison. Biomarkers studied included; multiple inflammatory proteins using multiplex assay; the metabolomics profile using LC/MS; and the miRNA profile using microarray. Results: Eighty five infants with perinatal depression were recruited. Analysis of inflammatory proteins consisted of exploratory analysis of 37 analytes conducted in a sub-population, followed by validation of all significantly altered analytes in the remaining population. IL-6 and IL-6 differed significantly in infants with a moderate/severely abnormal vs. a normal-mildly abnormal EEG in both cohorts (Exploratory: p=0.016, p=0.005: Validation: p=0.024, p=0.039; respectively). Metabolomic analysis demonstrated a perturbation in 29 metabolites. A Cross- validated Partial Least Square Discriminant Analysis model was developed, which accurately predicted HIE with an AUC of 0.92 (95% CI: 0.84-0.97). Analysis of the miRNA profile found 70 miRNA significantly altered between moderate/severely encephalopathic infants and controls. miRNA target prediction databases identified potential targets for the altered miRNA in pathways involved in cellular metabolism, cell cycle and apoptosis, cell signaling, and the inflammatory cascade. Conclusion: This thesis has demonstrated that the recruitment of a large cohortof asphyxiated infants, with cord blood carefully biobanked, and detailed early neurophysiological and clinical assessment recorded, is feasible. Additionally the results described, provide potential alternate and novel blood based biomarkers for the identification and assessment of HIE.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Elective repeat caesarean delivery (ERCD) rates have been increasing worldwide, thus prompting obstetric discourse on the risks and benefits for the mother and infant. Yet, these increasing rates also have major economic implications for the health care system. Given the dearth of information on the cost-effectiveness related to mode of delivery, the aim of this paper was to perform an economic evaluation on the costs and short-term maternal health consequences associated with a trial of labour after one previous caesarean delivery compared with ERCD for low risk women in Ireland.Methods: Using a decision analytic model, a cost-effectiveness analysis (CEA) was performed where the measure of health gain was quality-adjusted life years (QALYs) over a six-week time horizon. A review of international literature was conducted to derive representative estimates of adverse maternal health outcomes following a trial of labour after caesarean (TOLAC) and ERCD. Delivery/procedure costs derived from primary data collection and combined both "bottom-up" and "top-down" costing estimations.Results: Maternal morbidities emerged in twice as many cases in the TOLAC group than the ERCD group. However, a TOLAC was found to be the most-effective method of delivery because it was substantially less expensive than ERCD ((sic)1,835.06 versus (sic)4,039.87 per women, respectively), and QALYs were modestly higher (0.84 versus 0.70). Our findings were supported by probabilistic sensitivity analysis.Conclusions: Clinicians need to be well informed of the benefits and risks of TOLAC among low risk women. Ideally, clinician-patient discourse would address differences in length of hospital stay and postpartum recovery time. While it is premature advocate a policy of TOLAC across maternity units, the results of the study prompt further analysis and repeat iterations, encouraging future studies to synthesis previous research and new and relevant evidence under a single comprehensive decision model.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND & AIMS: Prophylactic administration of interleukin (IL)-10 decreases the severity of experimental pancreatitis. Prevention of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis in humans is a unique model to study the potential role of IL-10 in this setting. METHODS: In a single-center, double-blind, randomized, placebo-controlled study, the effect of a single injection of 4 microg/kg (group 1) or 20 microg/kg (group 2) IL-10 was compared with that of placebo (group 0), all administered 30 minutes before therapeutic ERCP. The primary endpoint was the effect of IL-10 on serum levels of amylases and lipases measured 4, 24, and 48 hours after ERCP. The secondary objective was to evaluate changes in plasma cytokines (IL-6, IL-8, tumor necrosis factor) at the same time points and the incidence of acute pancreatitis in the 3 groups. Subjects undergoing a first therapeutic ERCP were eligible for inclusion. RESULTS: A total of 144 patients were included. Seven were excluded based on intention to treat (n = 1) or per protocol (n = 6). Forty-five, 48, and 44 patients remained in groups 0, 1, and 2, respectively. The 3 groups were comparable for age, sex, underlying disease, indication for treatment, type of treatment, and plasma levels of C-reactive protein (CRP), cytokines, and hydrolases at baseline. No significant difference was observed in CRP, cytokine, and hydrolase plasma levels after ERCP. Forty-three patients developed hyperhydrolasemia (18 in group 0, 14 in group 1, and 11 in group 2; P = 0.297), and 19 patients developed acute clinical pancreatitis (11 in group 0, 5 in group 1, 3 in group 2; P = 0.038). Two severe cases were observed in the placebo group. No mortality related to ERCP was observed. Logistic regression identified 3 independent risk factors for post-therapeutic ERCP pancreatitis: IL-10 administration (odds ratio [OR], 0.46; 95% confidence interval [95% CI], 0.22-0.96; P = 0.039), pancreatic sphincterotomy (OR, 5.04; 95% CI, 1.53-16.61; P = 0.008), and acinarization (OR, 8.19; 95% CI, 1.83-36.57; P = 0.006). CONCLUSIONS: A single intravenous dose of IL-10, given 30 minutes before the start of the procedure, independently reduces the incidence of post-therapeutic ERCP pancreatitis.