Development and optimization of an indirect enzyme-linked immunosorbent assay for the determination of Hexoestrol

An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of hexoestrol (HES) was developed, optimized and validated for the analysis of HES in pork. Many parameters, such as the volume ratio of solution A and solution B, colour developing time, pH value, incubation time, the volume ratio of the standard solution and diluted antiserum, blocking solution, blocking condition, coating solution and coating condition were studied and optimized in the paper. The regression equation of the final inhibition curve is y = - 0.3345x + 1.4955, R²=0.9913. The linear range is 0.1-8.1 ng/ml, and the IC₅₀ is 0.671 ng/ml. The specificity of the assay was evaluated by the cross-reactivity rates of six compounds, of which two structurally related compounds had a relatively higher cross-reactivity rate of 25% and 6%. HES was added into a pork sample at 5 ng/g level and then the sample was extracted. The recovery is between 49.6% and 79.2%, and the variation coefficient is 0.164.     

Optimized and combined T1 and B1 mapping technique for fast and accurate T1 quantification in contrast-enhanced abdominal MRI.

Fast T(1) mapping techniques are a valuable means of quantitatively assessing the distribution and dynamics of intravenously or orally applied paramagnetic contrast agents (CAs) by noninvasive imaging. In this study a fast T(1) mapping technique based on the variable flip angle (VFA) approach was optimized for accurate T(1) quantification in abdominal contrast-enhanced (CE) MRI. Optimization methods were developed to maximize the signal-to-noise ratio (SNR) and ensure effective RF and gradient spoiling, as well as a steady state, for a defined T(1) range of 100-800 ms and a limited acquisition time. We corrected B(1) field inhomogeneities by performing an additional measurement using an optimized fast B(1) mapping technique. High-precision in vitro and abdominal in vivo T(1) maps were successfully generated at a voxel size of 2.8 x 2.8 x 15 mm(3) and a temporal resolution of 2.3 s per T(1) map on 1.5T and 3T MRI systems. The application of the proposed fast T(1) mapping technique in abdominal CE-MRI enables noninvasive quantification of abdominal tissue perfusion and vascular permeability, and offers the possibility of quantitatively assessing dilution, distribution, and mixing processes of labeled solutions or drugs in the gastrointestinal tract.     

输尿管镜气压弹道碎石治疗输尿管结石(附108例报告)

目的探讨输尿管镜气压道弹碎石术治疗输尿管结石的临床疗效.方法在输尿管镜窥视下采用气压弹道碎石机对108例输尿管结石进行治疗.结果 103例原位碎石成功,总成功率95.3%,其中输尿管上段结石成功率为83.3%,中段结石为96.3%,下段结石为98.4%.平均碎石时间(4.5±2.2)min,术后1～3个月结石排净率100%.结论输尿管镜气压弹道碎石术治疗输尿管结石具有安全、有效、容易操作等特点,是治疗输尿管结石的首选方法.     

SMB色谱分离过程的建模与优化

基于物料平衡理论建立了SMB色谱分离过程的理想数学模型。以提高产品纯度和叫率为目标，依据Massimo三角形理论，研究了主要操作参数对SMB性能的影响。针对具体的分离象进行了仿真和操作条件寻优，并以此指导实际分离实验，得到满意的结果。说明了简化的模型在操作优化、参数设计和分离预测中的作用。     

曲肘式机构的优化设计

以功效系数为目标函数,相应地确定了设计变量和约束函数,对塑料注塑机合模机构的参数进行优化计算,提高了机构的综合性能。     

Optimization of parameter values for complex pulse sequences by simulated annealing: Application to 3D MP-RAGE imaging of the brain

A number of pulse sequence techniques, including magnetization-prepared gradient echo (MP-GRE), segmented GRE, and hybrid RARE, employ a relatively large number of variable pulse sequence parameters and acquire the image data during a transient signal evolution. These sequences have recently been proposed and/or used for clinical applications in the brain, spine, liver, and coronary arteries. Thus, the need for a method of deriving optimal pulse sequence parameter values for this class of sequences now exists. Due to the complexity of these sequences, conventional optimization approaches, such as applying differential calculus to signal difference equations, are inadequate. We have developed a general framework for adapting the simulated annealing algorithm to pulse sequence parameter value optimization, and applied this framework to the specific case of optimizing the white matter-gray matter signal difference for a T₁-weighted variable flip angle 3D MP-RAGE sequence. Using our algorithm, the values of 35 sequence parameters, including the magnetization-preparation RF pulse flip angle and delay time, 32 flip angles in the variable flip angle gradient-echo acquisition sequence, and the magnetization recovery time, were derived. Optimized 3D MP-RAGE achieved up to a 130% increase in white matter-gray matter signal difference compared with optimized 3D RF-spoiled FLASH with the same total acquisition time. The simulated annealing approach was effective at deriving optimal parameter values for a specific 3D MP-RAGE imaging objective, and may be useful for other imaging objectives and sequences in this general class.     

乳酸菌SK1.002产L-阿拉伯糖异构酶培养基优化及发酵条件

L-阿拉伯糖异构酶能将D-半乳糖异构成D-塔格糖。通过单因素试验和快速登高法对乳酸菌SK1.002产L-阿拉伯糖异构酶的培养基进行优化,确定发酵优化条件为（组分g/L）：麦芽糊精28,酵母膏10,玉米粉浆22,无水乙酸钠10,K3PO40.2,NaCl 0.01,FeSO4.7H2O 0.01,Mg-SO4.7H2O 0.2,MnSO4.2H2O 0.05,L-阿拉伯糖2.5。发酵初始pH 8.4,培养温度37℃,接种体积分数3%,培养时间12 h。在此发酵条件下,酶活达到了7.28 U/mL。