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排序方式: 共有2291条查询结果,搜索用时 90 毫秒
941.
Julian H. Elliott Fiona Wightman Ajantha Solomon Khader Ghneim Jeffrey Ahlers Mark J. Cameron Miranda Z. Smith Tim Spelman James McMahon Pushparaj Velayudham Gregor Brown Janine Roney Jo Watson Miles H. Prince Jennifer F. Hoy Nicolas Chomont Rémi Fromentin Francesco A. Procopio Joumana Zeidan Sarah Palmer Lina Odevall Ricky W. Johnstone Ben P. Martin Elizabeth Sinclair Steven G. Deeks Daria J. Hazuda Paul U. Cameron Rafick-Pierre Sékaly Sharon R. Lewin 《PLoS pathogens》2014,10(11)
942.
Gabriella Gamberale-Stille Lina Soderlind Niklas Janz Soren Nylin 《Insect Science》2014,21(4):499-506
In most phytophagous insects, the larval diet strongly affects future fitness and in species that do not feed on plant parts as adults, larval diet is the main source of nitrogen. In many of these insect-host plant systems, the immature larvae are considered to be fully dependent on the choice of the mothers, who, in turn, possess a highly developed host recognition system. This circumstance allows for a potential mother-offspring conflict, resulting in the female maximizing her fecundity at the expense of larval performance on suboptimal hosts. In two experiments, we aimed to investigate this relationship in the polyphagous comma butterfly, Polygonia c-album, by comparing the relative acceptance of low- and medium-ranked hosts between females and neonate larvae both within individuals between life stages, and between mothers and their offspring. The study shows a variation between females in oviposition acceptance of low-ranked hosts, and that the degree of acceptance in the mothers correlates with the probability of acceptance of the same host in the larvae. We also found a negative relationship between stages within individuals as there was a higher acceptance of lower ranked hosts in females who had abandoned said host as a larva. Notably, however, neonate larvae of the comma butterfly did not unconditionally accept to feed from the least favorable host species even when it was the only food source. Our results suggest the possibility that the disadvantages associated with a generalist oviposition strategy can be decreased by larval participation in host plant choice. 相似文献
943.
Large-scale production and evaluation of marker-free indica rice IR64 expressing phytoferritin genes
Norman Oliva Prabhjit Chadha-Mohanty Susanna Poletti Editha Abrigo Genelou Atienza Lina Torrizo Ruby Garcia Conrado Dueñas Jr. Mar Aristeo Poncio Jeanette Balindong Marina Manzanilla Florencia Montecillo Maricris Zaidem Gerard Barry Philippe Hervé Huxia Shou Inez H. Slamet-Loedin 《Molecular breeding : new strategies in plant improvement》2014,33(1):23-37
944.
Naili Zhang Mo Zhou Yumin Zhang Xusheng Wang Shaoying Ma Li Dong Ting Yang Lina Ma Baoxing Li 《Cell and tissue banking》2014,15(3):357-367
Defatting is an important procedure for the preparation of bone grafts because lipids in bone grafts strongly influence the osteointegration. Lipases have been widely used in different fields. However, study on the application to defatting process for bone grafts preparation has never been found so far. In this study, bone samples were treated respectively by lipase, NaHCO3/Na2CO3, acetone and deionized water. The lipids content of processed bone grafts was calculated in Soxhlet extractor method. Surface morphology of the bone grafts was observed under scanning electron microscope (SEM). DNA content of processed bone grafts was measured. Cytocompatibility was evaluated by co-culturing mouse preosteoblasts (MC3T3-E1) on defatted bone cubes. Proliferation rates of MC3T3-E1 were examined by cell counting kit-8 (CCK-8) assay. No statistically significant difference was found between lipids amount of bone processed by lipase (0.46 ± 0.16 %) and acetone (1.11 ± 0.13 %) (P > 0.05). Both of them were significantly lower than that in groups processed by Na2CO3/NaHCO3 (3.46 ± 0.69 %) and deionized water (8.88 ± 0.18 %) (P = 0.000). Only cell debris were discovered over the surface of bone processed by lipase or acetone, while lipid droplets were observed on bone processed by Na2CO3/NaHCO3 or water by SEM. The difference of DNA concentration between the bone processed by lipase (3.16 ± 0.81 ng/μl) and acetone (4.14 ± 0.40 ng/μl) is not statistically significant (P > 0.05). Both of them are significantly lower than that groups processed by Na2CO3/NaHCO3 (5.22 ± 0.38 ng/μl) and water (7.88 ± 0.55 ng/μl) (P < 0.05). MC3T3-E1 cells maintained their characteristic spreading on the trabecular surfaces of bone processed by lipase. There were no statistically significant differences among absorbance of lipase, acetone groups in CCK-8 assay. The application of lipase to bone tissue defatting appears to be a very promising technique for bone grafts preparation. 相似文献
945.
David A. Parry Lina Bida Katherine V. Towns Samuel G. Jacobson Manir Ali Rebecca Chance Lauren L. Daniele Matthew Adams Adam P. Booth Yasmin Rashid Tim M. Strom Dror Sharon Edward N. Pugh Jr. Chris F. Inglehearn 《American journal of human genetics》2009,84(5):683-109
Cone-rod dystrophy (CRD) is an inherited progressive retinal dystrophy affecting the function of cone and rod photoreceptors. By autozygosity mapping, we identified null mutations in the ADAM metallopeptidase domain 9 (ADAM9) gene in four consanguineous families with recessively inherited early-onset CRD. We also found reduced photoreceptor responses in Adam9 knockout mice, previously reported to be asymptomatic. In 12-month-old knockout mice, photoreceptors appear normal, but the apical processes of the retinal pigment epithelium (RPE) cells are disorganized and contact between photoreceptor outer segments (POSs) and the RPE apical surface is compromised. In 20-month-old mice, there is clear evidence of progressive retinal degeneration with disorganized POS and thinning of the outer nuclear layer (ONL) in addition to the anomaly at the POS-RPE junction. RPE basal deposits and macrophages were also apparent in older mice. These findings therefore not only identify ADAM9 as a CRD gene but also identify a form of pathology wherein retinal disease first manifests at the POS-RPE junction. 相似文献
946.
Yongzhen Tao Yangyang Zhang Lina Zhang 《International journal of biological macromolecules》2009,45(2):109-115
Two water-soluble polysaccharide-protein complexes, extracted from Pleurotus tuber-regium sclerotia, were modified chemically to obtain their sulfated and carboxymethylated derivatives. While C6 position of glucan was fully substituted, C2, C3, and C4 were only partially substituted by sulfate groups. C3, C4, and C6 position of glucan were partially substituted during the carboxymethylation. Chain conformation and antitumor activity of the native samples and their derivatives were studied. The native samples and derivatives existed in sphere conformation, and showed potent in vitro antitumor activities. Water-solubility and introduction of ionic groups played important roles in enhancing the antitumor activities of the polysaccharide–protein complexes. 相似文献
947.
A water-insoluble polysaccharide (PCS3-II) extracted from sclerotium of Poria cocos was identified as a linear (1 → 3)-β-d-glucan by 13C NMR and gas chromatography. Aqueous 0.5 M NaOH/0.2 M urea was a good solvent for PCS3-II and the dependence of intrinsic viscosity ([η]) on weight-average molecular weight (Mw) was established in the Mw range from 7.68 × 104 to 5.14 × 105 to be [η] = 3.39 × 10?2 at 25 °C by using laser light scattering and viscometry. The chain conformation parameters of PCS3-II in the 0.5 M NaOH/0.2 M urea solution was 2.3 (± 0.3) nm for persistence length (q), 580 g mol?1 nm?1 for molar mass per unit contour length (ML), 0.8 (± 0.2) nm for the diameter of the chain (d) and 3.63 for limited characteristic ratio (C∞). The results revealed, for the first time, that PCS3-II existed as a flexible chain in 0.5 M NaOH/0.2 M urea aqueous solution. 相似文献
948.
949.
950.
海刺参i型溶菌酶基因的重组表达及抑菌谱分析 总被引:5,自引:0,他引:5
将本实验室已分离到的海刺参 (Stichopus japonicus) i型溶菌酶的基因(GenBank Accession No. EF036468)亚克隆进原核表达载体pET32a(+)中, 构建重组质粒pET32a(+)-SjLys, 转化至大肠杆菌BL21(DE3)pLysS。阳性克隆子经诱导表达、亲和纯化和透析复性, 得到了酶活力为19.2 U/mg的重组SjLys (rSjLys), 并对rSjLys进行了抑菌谱测定。结果表明, rSjLys对革兰氏阳性菌和阴性菌均有抑制作用, 尤其对常见的海洋致病菌副溶血弧菌和铜绿假单胞菌具有很强的抑菌活性。更为显著的结果是, rSjLys经100oC、40 min加热处理后, 失活的rSjLys对革兰氏阳性菌和阴性菌的抑菌能力高于rSjLys的9%~25%。上述结果表明, 海刺参溶菌酶是一种具有糖苷酶活性和非酶抑菌活性的特殊的i型溶菌酶, 且具有很广的抑菌活性, 在海刺参机体先天免疫系统中是一个重要的效应分子。 相似文献