采用近红外光谱技术快速检测桃汁原汁含量的方法研究

利用近红外光谱技术结合偏最小二乘法（PLS）对桃汁样本中原汁的含量进行定量分析. 采用5种不同预处理方法优化检测数据,结果表明标准化预处理所建立的定量检测模型性能最优,其预测相关系数（R²_p）、预测均方根误差（RMSEP)、校正相关系数（R²_c）、校正均方根误差（RMSEC）分别为0.9988、0.0140、0.9973、0.0212. 研究为桃汁等果汁饮品中原汁含量的检测提供一种快速、无损、简便、廉价、准确的方法.     

NiTi太记忆合金的性能测试

研究了Φ0.5mm、Φ0.2mm的NiTi记忆合金丝的制备工艺，并对其进行了力学－－热学性能的测试，得到了应力、应变、温度和相变相互之间的函数关系曲线，为NiTi记忆合金丝在自适应结构中的应用奠定了基础。     

A complementary transposon tool kit for Drosophila melanogaster using P and piggyBac

With the availability of complete genome sequence for Drosophila melanogaster, one of the next strategic goals for fly researchers is a complete gene knockout collection. The P-element transposon, the workhorse of D. melanogaster molecular genetics, has a pronounced nonrandom insertion spectrum. It has been estimated that 87% saturation of the approximately 13,500-gene complement of D. melanogaster might require generating and analyzing up to 150,000 insertions. We describe specific improvements to the lepidopteran transposon piggyBac and the P element that enabled us to tag and disrupt genes in D. melanogaster more efficiently. We generated over 29,000 inserts resulting in 53% gene saturation and a more diverse collection of phenotypically stronger insertional alleles. We found that piggyBac has distinct global and local gene-tagging behavior from that of P elements. Notably, piggyBac excisions from the germ line are nearly always precise, piggyBac does not share chromosomal hotspots associated with P and piggyBac is more effective at gene disruption because it lacks the P bias for insertion in 5' regulatory sequences.     

Rescue of embryonic lethality in Mdm4-null mice by loss of Trp53 suggests a nonoverlapping pathway with MDM2 to regulate p53

The relationship between the neurosensory photoreceptors and the adjacent retinal pigment epithelium (RPE) controls not only normal retinal function, but also the pathogenesis of hereditary retinal degenerations. The molecular bases for both primary photoreceptor and RPE diseases that cause blindness have been identified. Gene therapy has been used successfully to slow degeneration in rodent models of primary photoreceptor diseases, but efficacy of gene therapy directed at photoreceptors and RPE in a large-animal model of human disease has not been reported. Here we study one of the most clinically severe retinal degenerations, Leber congenital amaurosis (LCA). LCA causes near total blindness in infancy and can result from mutations in RPE65 (LCA, type II; MIM 180069 and 204100). A naturally occurring animal model, the RPE65-/- dog, suffers from early and severe visual impairment similar to that seen in human LCA. We used a recombinant adeno-associated virus (AAV) carrying wild-type RPE65 (AAV-RPE65) to test the efficacy of gene therapy in this model. Our results indicate that visual function was restored in this large animal model of childhood blindness.     

A gravitationally lensed quasar with quadruple images separated by 14.62 arcseconds

Gravitational lensing is a powerful tool for the study of the distribution of dark matter in the Universe. The cold-dark-matter model of the formation of large-scale structures (that is, clusters of galaxies and even larger assemblies) predicts the existence of quasars gravitationally lensed by concentrations of dark matter so massive that the quasar images would be split by over 7 arcsec. Numerous searches for large-separation lensed quasars have, however, been unsuccessful. All of the roughly 70 lensed quasars known, including the first lensed quasar discovered, have smaller separations that can be explained in terms of galaxy-scale concentrations of baryonic matter. Although gravitationally lensed galaxies with large separations are known, quasars are more useful cosmological probes because of the simplicity of the resulting lens systems. Here we report the discovery of a lensed quasar, SDSS J1004 + 4112, which has a maximum separation between the components of 14.62 arcsec. Such a large separation means that the lensing object must be dominated by dark matter. Our results are fully consistent with theoretical expectations based on the cold-dark-matter model.     

Interception of comet Hyakutake's ion tail at a distance of 500 million kilometres

Remote sensing observations and the direct sampling of material from a few comets have established the characteristic composition of cometary gas. This gas is ionized by solar ultraviolet radiation and the solar wind to form 'pick-up' ions, ions in a low ionization state that retain the same compositional signatures as the original gas. The pick-up ions are carried outward by the solar wind, and they could in principle be detected far from the coma (Sampling of pick-up ions has also been used to study interplanetary dust, Venus' tail and the interstellar medium.) Here we report the serendipitous detection of cometary pick-up ions, most probably associated with the tail of comet Hyakutake, at a distance of 3.4 AU from the nucleus. Previous observations have provided a wealth of physical and chemical information about a small sample of comets, but this detection suggests that remote sampling of comet compositions, and the discovery of otherwise invisible comets, may be possible.     

Immune Algorithm for Selecting Optimum Services in Web Services Composition

0 IntroductionInha rveec eenmte yregaerds a,sa t ghreo Iwnitnegrn neut mdbeverel oofps W aetb a S fearsvtic reast e( .W TSshe)Webis nowevolving into a distributed device of computationfroma collection of information resources[1]. But individualWeb services usually cannot satisfy some customers’require-ments ,so we always needtointegrate existingservices to cre-ate newvalue-added composed services .The process model underlying a composite identifies thefunctionalities required by the servic…