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A two-part investigation was undertaken to determine whether a four- or a five-flap Z-plasty gives the greatest increase in length (deepening) over the same radius of a web. In part A, flaps were designed on a model of a webspace made from a plastic frame and Speedo fabric; four types of flaps, three different central limb lengths, and three trials for each length gave a total of 36 observations. In part B, flaps were designed on the natural axillary webs of the pig; three Yorkshire pigs with one type of flap per axillary web gave a total of 12 observations. In part A, the stereometric elongation (percent deepening) produced by the five-flap Z-plasty was similar to that of a single 60-degree Z-plasty (4-cm central limb; five-flap versus a single Z procedure, 72.5+/-4.3 versus 75.0+/-2.5 percent). The 90-degree four-flap procedure gave a 1.59 times greater deepening than the five-flap procedure (4-cm central limb; 90-degree four flap technique, 114.2+/-1.4 percent). The 120-degree four-flap technique gave 2.0 and 1.26 times greater deepening than the five-flap and 90-degree four-flap procedures, respectively (4-cm central limb; 120-degree four-flap technique, 144.2+/-1.4 percent). In part B, the 90-degree four-flap Z-plasty again produced a significantly greater lengthening (1.57 times) than the five-flap procedure (132.7+/-6.4 versus 84.0+/-4.0 percent; p<0.05), and the percentage of elongation of the 120-degree four-flap procedure was 1.27 times greater than that of the 90-degree four-flap technique (167.3+/-7.0 versus 131.3+/-2.3 percent; p < 0.05). In conclusion, the four-flap Z-plasty produced greater webspace deepening than that of the five-flap Z-plasty. The 120-degree four-flap procedure gave the greatest percentage of elongation, but it was more difficult to design and close than the 90-degree four-flap Z-plasty.  相似文献   
2.
S-phase and DNA damage promote increased ribonucleotide reductase (RNR) activity. Translation of RNR1 has been linked to the wobble uridine modifying enzyme tRNA methyltransferase 9 (Trm9). We predicted that changes in tRNA modification would translationally regulate RNR1 after DNA damage to promote cell cycle progression. In support, we demonstrate that the Trm9-dependent tRNA modification 5-methoxycarbonylmethyluridine (mcm⁵U) is increased in hydroxyurea (HU)-induced S-phase cells, relative to G₁ and G₂, and that mcm⁵U is one of 16 tRNA modifications whose levels oscillate during the cell cycle. Codon-reporter data matches the mcm⁵U increase to Trm9 and the efficient translation of AGA codons and RNR1. Further, we show that in trm9Δ cells reduced Rnr1 protein levels cause delayed transition into S-phase after damage. Codon re-engineering of RNR1 increased the number of trm9Δ cells that have transitioned into S-phase 1 h after DNA damage and that have increased Rnr1 protein levels, similar to that of wild-type cells expressing native RNR1. Our data supports a model in which codon usage and tRNA modification are regulatory components of the DNA damage response, with both playing vital roles in cell cycle progression.  相似文献   
3.
粘虫生殖的研究——Ⅱ.补充营养对生殖力的效应   总被引:1,自引:0,他引:1  
郭郛  刘金龙 《昆虫学报》1964,(6):785-794
粘虫成虫需补充取食糖类,方能完成飞翔(包括迁飞)、交配、产卵等活动。我们用了18种糖类来测定粘虫取食的范围,并观察糖类对生殖力的效应。试验结果表明:粘虫能取食葡萄糖、果糖、甘露糖、半乳糖、蔗糖、麦芽糖、海藻糖、棉子糖、甘油、甘露醇等,能完成正常生殖活动,产下数百粒卵,或上千粒卵,卵能孵化;但取食水、木糖、山梨糖、乳糖、糊精、淀粉、糖元等后,只能产下几粒卵,卵不能孵化。食量依糖液浓度而稍有变化,产卵前期取食量最高。 文中讨论各种糖的营养效价,并比较了各种糖类对不同昆虫生存、飞翔、生殖等效应的异同。  相似文献   
4.
Migration, invasion, metastasis and angiogenesis associated with cancer depend on the surrounding microenvironment. Angiogenesis, the growth of new capillaries, is a regulator of cancer growth and a useful target for cancer therapy. We examined matrix protein interactions in a gastric cancer cell culture that was treated with different doses of caffeic acid (3,4-dihydroxycinnamic acid) phenethyl ester (CAPE). We also investigated the relations among the levels of vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), endostatin (ES) and trombospondin-1 (TSP-1). Cytotoxity of CAPE was measured using the 3-(4,5-dmethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. We examined the behavior of cells on laminin and collagen I coated surfaces in response to the angiogenic effect of these matrix molecules. We examined the protein alterations of these matrix molecules immunohistochemically and measured the levels of VEGF, MMP-9, ES and TSP-1 using the ELISA test. We showed that application of CAPE to the gastric cancer cell line on tissue culture plastic, laminin and collagen I significantly decreased the VEGF and MMP-9 protein levels. We found that TSP-1 levels were increased significantly in the gastric cancer cells after application of CAPE. The protein levels of gastric cancer cells also were increased significantly when tissue was cultured on laminin and collagen I. Application of CAPE to cells on laminin or collagen I coated surfaces significantly increased all of the proteins except ES. ES levels were increased on the collagen I covered surfaces, but the laminin surface decreased the levels of ES significantly. We demonstrated the beneficial effect of CAPE on a gastric cancer cell line including inhibition of proliferation and induction of some proteins that might be related to decreased angiogenesis.  相似文献   
5.
Cellular responses to DNA damage can prevent mutations and death. In this study, we have used high throughput screens and developed a comparative genomic approach, termed Functionome mapping, to discover conserved responses to UVC-damage. Functionome mapping uses gene ontology (GO) information to link proteins with similar biological functions from different organisms, and we have used it to compare 303, 311 and 288 UVC-toxicity modulating proteins from Escherichia coli, Schizosaccharomyces pombe and Saccharomyces cerevisiae, respectively. We have demonstrated that all three organisms use DNA repair, translation and aerobic respiration associated processes to modulate the toxicity of UVC, with these last two categories highlighting the importance of ribosomal proteins and electron transport machinery. Our study has demonstrated that comparative genomic approaches can be used to identify conserved responses to damage, and suggest roles for translational machinery and components of energy metabolism in optimizing the DNA damage response.  相似文献   
6.
There has long been interest in determining if mass ivermectin administration for onchocerciasis has 'unknowingly' interrupted lymphatic filariasis (LF) transmission where the endemicity of the two diseases' overlaps. We studied 11 communities in central Nigeria entomologically for LF by performing mosquito dissections on Anopheline LF vectors. Six of the communities studied were located within an onchocerciasis treatment zone, and five were located outside of that zone. Communities inside the treatment zone had been offered ivermectin treatment for two-five years, with a mean coverage of 81% of the eligible population (range 58–95%). We found 4.9% of mosquitoes were infected with any larval stage of W. bancrofti in the head or thorax in 362 dissections in the untreated villages compared to 4.7% infected in 549 dissections in the ivermectin treated villages (Mantel-Haenszel ChiSquare 0.02, P = 0.9). We concluded that ivermectin annual therapy for onchocerciasis has not interrupted transmission of Wuchereria bancrofti (the causative agent of LF in Nigeria).  相似文献   
7.
一.引言 东亚飞蝗自古以来是我国农业上的剧害之一,它们摧毁植物的能力极为巨大,而且所嗜食的主要是禾本科植物,其中包括我们用以生产粮食的农作物。我们的祖先在和这种害虫作斗争之中,对于它们的取食习性早有所观察和了解。晋书石勒载记中首先记载蝗虫“不食三豆三麻”,以后如王桢的“农书”(1313),徐光启的“农政全书”(1630),  相似文献   
8.
The EPT index (Ephemeroptera, Plecoptera and Trichoptera) may be skewed by the wide tolerance to multiple stressors of the Baetid, Caenid and Hydropsychid families, which affects the performance of the EPT index as an indicator of multiple stressors in aquatic ecosystems. The effect of the BCH families on the EPT index was evaluated and alternatives were considered to improve its performance. The hypothesis that the removal of the BCH families improves sensitivity of the EPT index to human-induced stressors in streams and rivers was tested. Macroinvertebrates were collected in January–March 2009 at 22 sites in the Nyando and Nzoia Rivers, Lake Victoria basin, Kenya. Nine derivatives and modifications of the EPT index were tested for responses to a disturbance gradient, ranked into three condition categories (reference, intermediate and impaired). The sensitivity of the proportionate abundance derivative of the EPT index improved when the BCH families were removed, whereas that of the richness derivative improved marginally. Other modifications considered performed poorly when compared with the EPT-BCH metrics. Wide distribution of the BCH across all sites, irrespective of the level of disturbance, reduced the sensitivity of the EPT index in the studied streams. The removal of the BCH families enhanced the sensitivity of the index to multiple stressors in Afrotropical streams and rivers.  相似文献   
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