Numerical simulation of(T_2,T_1) 2D NMR and fluid responses

One-dimensional nuclear magnetic resonance （1D NMR） logging technology is limited for fluid typing, while two-dimensional nuclear magnetic resonance （2D NMR） logging can provide more parameters including longitudinal relaxation time （71） and transverse relaxation time （T2） relative to fluid types in porous media. Based on the 2D NMR relaxation mechanism in a gradient magnetic field, echo train simulation and 2D NMR inversion are discussed in detail. For 2D NMR inversion, a hybrid inversion method is proposed based on the damping least squares method （LSQR） and an improved truncated singular value decomposition （TSVD） algorithm. A series of spin echoes are first simulated with multiple waiting times （Tws） in a gradient magnetic field for given fluid models and these synthesized echo trains are inverted by the hybrid method. The inversion results are consistent with given models. Moreover, the numerical simulation of various fluid models such as the gas-water, light oil-water, and vicious oil-water models were carried out with different echo spacings （TEs） and Tws by this hybrid method. Finally, the influences of different signal-to-noise ratios （SNRs） on inversion results in various fluid models are studied. The numerical simulations show that the hybrid method and optimized observation parameters are applicable to fluid typing of gas-water and oil-water models.

新型γ-环糊精衍生物Aom0498-1和Aom0498-3的肌松拮抗作用(英文)

目的寻找并筛选可选择性地逆转甾类非去极化肌松药的肌松拮抗剂。方法应用一锅法合成了2种6-脱氧-6-硫醚乙酰基甘氨酸-γ-环糊精衍生物Aom0498-1和Aom0498-3。采用3种动物模型测定Aom0498-1和Aom0498-3对罗库溴铵导致的神经-肌肉阻滞的逆转作用:①小鼠体外神经-膈肌标本模型中的肌张力恢复比率。将小鼠随机分成5组:生理盐水(正常对照组),γ-环糊精1.8,3.6,5.4μmol·L-1,Aom0498-1 1.8,3.6,5.4μmol·L-1,Aom0498-3 1.8,3.6,5.4μmol·L-1以及舒格麻坦(sugammadex)1.8,3.6,5.4μmol·L-1(阳性对照)组;②豚鼠体内模型中的4个成串刺激比恢复50%及75%的时间。将豚鼠随机分为5组:生理盐水(正常对照),γ-环糊精2 mg·kg-1,Aom0498-1 2 mg·kg-1,Aom0498-3 2 mg·kg-1以及舒格麻坦2 mg·kg-1(阳性对照)组;③家兔体内模型中的捏耳反射恢复时间。将动物随机分为5组:生理盐水(正常对照组),γ-环糊精6 mg·kg-1,Aom0498-1 6 mg·kg-1,Aom0498-3 6 mg·kg-1以及舒格麻坦6 mg·kg-1(阳性对照)组。同时,对Aom0498-1以及Aom0498-3的单次给药毒性也进行了初步的检测,并与舒格麻坦进行了比较。将小鼠随机分为生理盐水组,Aom0498-1 2,4和8 g·kg-1组,Aom0498-3 2,4和8 g·kg-1组以及舒格麻坦2,4和8 g·kg-1组。结果①在小鼠神经-膈肌标本模型中,Aom0498-1 1.8,3.6和5.4μmol·L-1组肌张力恢复比例分别为(2.5±1.0)%,(6.9±2.6)%和(24.5±9.1)%,同浓度Aom0498-3组分别为(17.4±1.7)%,(65.5±0.6)%及(100.0±8.9)%,均显著高于同浓度γ-环糊精组的(1.1±0.5)%,(2.6±0.7)%和(10.3±6.1)%(P<0.05)。Aom0498-3 1.8,3.6和5.4μmol·L-1组肌张力恢复比例显著高于相应同浓度的舒格麻坦组(P<0.05),Aom0498-1 1.8,3.6和5.4μmol·L-1组肌张力恢复比例则显著低于相同浓度的舒格麻坦组(P<0.05)。②在豚鼠模型中,Aom0498-3 2 mg·kg-1组4个成串刺激比恢复至50%及75%的时间显著低于γ-环糊精2 mg·kg-1组(P<0.05),与舒格麻坦2 mg·kg-1组相当;Aom0498-1 2 mg·kg-1组恢复至50%时间显著低于γ-环糊精2 mg·kg-1组,Aom0498-1 2 mg·kg-1组恢复至75%时间显著高于舒格麻坦2 mg·kg-1组。③在家兔模型中,Aom0498-1 6 mg·kg-1组和Aom0498-36 mg·kg-1组恢复时间显著低于γ-环糊精6 mg·kg-1组(P<0.05)。Aom0498-3 6 mg·kg-1组恢复时间显著低于舒格麻坦6 mg·kg-1组。单次给药毒性检测结果显示,舒格麻坦2,4及8 g·kg-1组中出现一过性或中等程度副作用的小鼠数多于Aom0498-1以及Aom0498-3对应浓度组。结论合成的Aom0498-1和Aom0498-3具有较高的逆转罗库溴铵活性的作用,提示该系列γ-环糊精衍生物可作为候选药物用于选择性肌松拮抗剂的开发。