New matrix, metal-phthalocyanine （MPc）, of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS） was used for analysis of small molecules （usually 〈500 Da）. By using MPcs a...New matrix, metal-phthalocyanine （MPc）, of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS） was used for analysis of small molecules （usually 〈500 Da）. By using MPcs as matrices, small molecular samples were moved to high mass-to-charge region where there was no interference caused by the traditional matrices. The mass of the target analvte was obtained by simple calculation.展开更多
Matrix metalloproteinase-9（MMP-9） and p53 genes play an essential role in the multi-step process of tumorigenesis in lung cancer. Single nucleotide polymorphisms（SNPs） of MMP-9 and p53 genes are associated with th...Matrix metalloproteinase-9（MMP-9） and p53 genes play an essential role in the multi-step process of tumorigenesis in lung cancer. Single nucleotide polymorphisms（SNPs） of MMP-9 and p53 genes are associated with the risk and progression of many cancers. In this study, we evaluated the association of the R279Q polymorphism of MMP-9 or the A1/A2 polymorphism of p53 gcne with the risk of no-small-cell lung cancer（NSCLC） in Han population of Northeast China. We examined the frequency of SNPs in the two kinds of genes of 50 patients with NSCLC and 50 cancer-free controls frequency-matched by age and sex. Polymerase chain reaction-restriction fragment length polymorphism（PCR-RFLP） technique was used to determine the genotypes. The results indicate that the 279RR genotype in MMP-9 gene and the A1/A2 genotype in p53 gene show a significantly increased risk of NSCLC. Therefore, the MMP-9 279RR and p53 A1/A2 genotypes may be used as markers for susceptibility to NSCLC in Han population of Northeast China.展开更多
In this article the mathematical model of complex regulated electric system in matrix form is developed. This mathematical model makes it possible to study the steady-state stability of a complex electrical system by ...In this article the mathematical model of complex regulated electric system in matrix form is developed. This mathematical model makes it possible to study the steady-state stability of a complex electrical system by determining the eigenvalues of the dynamics matrix. The model of an electrical system that reflects transient processes for small deviations is convenient, both algorithmically and computationally, in particular, in cases of their joint solution with steady-state equations—the equations of nodal voltages. The obtained results in the form of the eigenvalues of the matrix spectrum are qualitatively the same as the results of classical studies, which is a consequence of the adequacy of the proposed model and the correct reflection of the dynamic processes occurring in a real electrical system. In addition, the equations obtained are of independent importance for the analysis of various modes, including transient, electrical systems of any complexity.展开更多
针对传统的自适应波束形成算法在目标导向矢量失配及接收数据的协方差矩阵存在误差时,性能急剧下降的问题,提出了一种基于小快拍场景的联合协方差矩阵重构,及导向矢量优化的稳健波束形成算法。对不确定集约束求解得到干扰导向矢量,根据...针对传统的自适应波束形成算法在目标导向矢量失配及接收数据的协方差矩阵存在误差时,性能急剧下降的问题,提出了一种基于小快拍场景的联合协方差矩阵重构,及导向矢量优化的稳健波束形成算法。对不确定集约束求解得到干扰导向矢量,根据稀疏干扰来向的导向矢量近似正交,求出干扰导向矢量对应的干扰功率,从而完成协方差矩阵重构;对期望信号来向及其邻域进行权值求解,对加权后的数据特征分解,利用多信号分类(Multiple Signal Classification, MUSIC)谱估计算法对信号区域积分得到信号协方差矩阵,将其主特征值近似为期望信号的导向矢量完成重新估计。仿真结果表明,在无误差时,算法输出信干噪比(Signal to Interference Plus Noise Ratio, SINR)接近理论最优;在多种误差环境下输出性能随信噪比(Signal to Noise Ratio, SNR)的变化均具有较好的稳健性,并且在信号来向可精准形成波束;在小快拍时可以较快收敛至理论最优值。展开更多
目的探讨雌激素对同型半胱氨酸(Hcy)损伤小鼠脑微血管内皮细胞株(bEnd.3)后基质金属蛋白酶(MMP)-9、MMP-2和紧密连接蛋白Occludin表达的影响及其对脑小血管病的保护作用和机制。方法采用Hcy、β-雌二醇分别处理bEnd.3细胞,以细胞增殖及...目的探讨雌激素对同型半胱氨酸(Hcy)损伤小鼠脑微血管内皮细胞株(bEnd.3)后基质金属蛋白酶(MMP)-9、MMP-2和紧密连接蛋白Occludin表达的影响及其对脑小血管病的保护作用和机制。方法采用Hcy、β-雌二醇分别处理bEnd.3细胞,以细胞增殖及毒性检测试剂盒确定最适药物浓度。实验细胞分为对照组(仅加培养液)、Hcy组(200μmol/L的Hcy)、β-雌二醇组(200 nmol/L的β-雌二醇)、联合组(200 nmol/L的β-雌二醇处理30 min后再加入200μmol/L的Hcy),各组均处理6 h。Western blot法检测各组细胞中MMP-9、MMP-2和Occludin表达。结果各组24 h、48 h的MMP-9、MMP-2和Occludin表达比较,差异无统计学意义(P>0.05)。与对照组比较,Hcy组72 h的MMP-9和MMP-2表达明显升高(1.45±0.14 vs 1.00±0.00,1.35±0.15 vs 1.00±0.00,P<0.05),Occludin表达明显降低(0.64±0.05 vs 1.00±0.00,P<0.05)。与Hcy组比较,联合组72 h的MMP-9和MMP-2表达明显降低(0.84±0.19 vs 1.45±0.14,1.01±0.78 vs 1.35±0.15,P<0.05),Occludin表达明显升高(0.91±0.10 vs 0.64±0.05,P<0.05)。结论在Hcy处理的bEnd.3中β-雌二醇能够改善血脑屏障损伤,从而导致MMP-9和MMP-2表达降低,Occludin表达升高。展开更多
针对岩爆样本数据噪声高、数量少从而导致岩爆等级预测准确率较低的问题,提出了基于非线性分数阶中值鉴别空间学习(nonlinear fractional-order median discriminative space learning,NFMDSL)的岩爆预测方法。该方法用类中值代替类均值...针对岩爆样本数据噪声高、数量少从而导致岩爆等级预测准确率较低的问题,提出了基于非线性分数阶中值鉴别空间学习(nonlinear fractional-order median discriminative space learning,NFMDSL)的岩爆预测方法。该方法用类中值代替类均值,构建了中值鉴别空间学习方法,更好地保留了样本的有效信息,降低了噪声对预测效果的影响。为了有效捕捉岩爆数据间的非线性鉴别结构,进一步借助核技术将样本数据投影到核空间中。此外,引入分数阶对散度矩阵的特征值和奇异值进行重新估计,可以从少量样本中提取出具有良好区分能力的岩爆特征。结果表明,NFMDSL方法在岩爆等级预测中的平均准确率达到了95.75%,相比其他方法具有更高的准确率和更强的鲁棒性。该方法能够有效应用于矿山和隧道工程领域的岩爆预测。展开更多
基金supported financially by NSFC(Nos.90717120 and 20435030),MOST(No.2007CB714504)Sino German Center for Research Promotion(No.GZ364) and CAS(No.KJCX2-YW-H11).
文摘New matrix, metal-phthalocyanine （MPc）, of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS） was used for analysis of small molecules （usually 〈500 Da）. By using MPcs as matrices, small molecular samples were moved to high mass-to-charge region where there was no interference caused by the traditional matrices. The mass of the target analvte was obtained by simple calculation.
文摘Matrix metalloproteinase-9（MMP-9） and p53 genes play an essential role in the multi-step process of tumorigenesis in lung cancer. Single nucleotide polymorphisms（SNPs） of MMP-9 and p53 genes are associated with the risk and progression of many cancers. In this study, we evaluated the association of the R279Q polymorphism of MMP-9 or the A1/A2 polymorphism of p53 gcne with the risk of no-small-cell lung cancer（NSCLC） in Han population of Northeast China. We examined the frequency of SNPs in the two kinds of genes of 50 patients with NSCLC and 50 cancer-free controls frequency-matched by age and sex. Polymerase chain reaction-restriction fragment length polymorphism（PCR-RFLP） technique was used to determine the genotypes. The results indicate that the 279RR genotype in MMP-9 gene and the A1/A2 genotype in p53 gene show a significantly increased risk of NSCLC. Therefore, the MMP-9 279RR and p53 A1/A2 genotypes may be used as markers for susceptibility to NSCLC in Han population of Northeast China.
文摘In this article the mathematical model of complex regulated electric system in matrix form is developed. This mathematical model makes it possible to study the steady-state stability of a complex electrical system by determining the eigenvalues of the dynamics matrix. The model of an electrical system that reflects transient processes for small deviations is convenient, both algorithmically and computationally, in particular, in cases of their joint solution with steady-state equations—the equations of nodal voltages. The obtained results in the form of the eigenvalues of the matrix spectrum are qualitatively the same as the results of classical studies, which is a consequence of the adequacy of the proposed model and the correct reflection of the dynamic processes occurring in a real electrical system. In addition, the equations obtained are of independent importance for the analysis of various modes, including transient, electrical systems of any complexity.
文摘针对传统的自适应波束形成算法在目标导向矢量失配及接收数据的协方差矩阵存在误差时,性能急剧下降的问题,提出了一种基于小快拍场景的联合协方差矩阵重构,及导向矢量优化的稳健波束形成算法。对不确定集约束求解得到干扰导向矢量,根据稀疏干扰来向的导向矢量近似正交,求出干扰导向矢量对应的干扰功率,从而完成协方差矩阵重构;对期望信号来向及其邻域进行权值求解,对加权后的数据特征分解,利用多信号分类(Multiple Signal Classification, MUSIC)谱估计算法对信号区域积分得到信号协方差矩阵,将其主特征值近似为期望信号的导向矢量完成重新估计。仿真结果表明,在无误差时,算法输出信干噪比(Signal to Interference Plus Noise Ratio, SINR)接近理论最优;在多种误差环境下输出性能随信噪比(Signal to Noise Ratio, SNR)的变化均具有较好的稳健性,并且在信号来向可精准形成波束;在小快拍时可以较快收敛至理论最优值。
文摘目的探讨雌激素对同型半胱氨酸(Hcy)损伤小鼠脑微血管内皮细胞株(bEnd.3)后基质金属蛋白酶(MMP)-9、MMP-2和紧密连接蛋白Occludin表达的影响及其对脑小血管病的保护作用和机制。方法采用Hcy、β-雌二醇分别处理bEnd.3细胞,以细胞增殖及毒性检测试剂盒确定最适药物浓度。实验细胞分为对照组(仅加培养液)、Hcy组(200μmol/L的Hcy)、β-雌二醇组(200 nmol/L的β-雌二醇)、联合组(200 nmol/L的β-雌二醇处理30 min后再加入200μmol/L的Hcy),各组均处理6 h。Western blot法检测各组细胞中MMP-9、MMP-2和Occludin表达。结果各组24 h、48 h的MMP-9、MMP-2和Occludin表达比较,差异无统计学意义(P>0.05)。与对照组比较,Hcy组72 h的MMP-9和MMP-2表达明显升高(1.45±0.14 vs 1.00±0.00,1.35±0.15 vs 1.00±0.00,P<0.05),Occludin表达明显降低(0.64±0.05 vs 1.00±0.00,P<0.05)。与Hcy组比较,联合组72 h的MMP-9和MMP-2表达明显降低(0.84±0.19 vs 1.45±0.14,1.01±0.78 vs 1.35±0.15,P<0.05),Occludin表达明显升高(0.91±0.10 vs 0.64±0.05,P<0.05)。结论在Hcy处理的bEnd.3中β-雌二醇能够改善血脑屏障损伤,从而导致MMP-9和MMP-2表达降低,Occludin表达升高。
文摘针对岩爆样本数据噪声高、数量少从而导致岩爆等级预测准确率较低的问题,提出了基于非线性分数阶中值鉴别空间学习(nonlinear fractional-order median discriminative space learning,NFMDSL)的岩爆预测方法。该方法用类中值代替类均值,构建了中值鉴别空间学习方法,更好地保留了样本的有效信息,降低了噪声对预测效果的影响。为了有效捕捉岩爆数据间的非线性鉴别结构,进一步借助核技术将样本数据投影到核空间中。此外,引入分数阶对散度矩阵的特征值和奇异值进行重新估计,可以从少量样本中提取出具有良好区分能力的岩爆特征。结果表明,NFMDSL方法在岩爆等级预测中的平均准确率达到了95.75%,相比其他方法具有更高的准确率和更强的鲁棒性。该方法能够有效应用于矿山和隧道工程领域的岩爆预测。
