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Resource allocation patterns, as quantified by residual food intake (RFI), and the consequences for offspring development were investigated during lactation in 96 females of a mouse line selected for 104 generations for high litter size at birth (S-line) and in 87 females of a non-selected control line (C-line). Litters of 45 C-line dams (Cs) and 48 S-line dams (Ss) were standardised (s) at birth; other dams (ns) supported total number of pups born (Cns and Sns, respectively). RFI during lactation was significantly lower in Sns-dams than in C-line dams and Sns-dams. After weaning Sns-dams seemed to be able to restore the negative resource situation. Sns-pups were about 25% less mature than Cns-pups at all times. Maturity was similar for Cs- and Ss-pups from 2 d in lactation on, and about 18% and 53% higher than Cns- and Sns-pups. The pre-weaning mortality rate was significantly higher in Sns-litters (35.6 ± 2.76) than in Cns-litters (4.95 ± 2.23). The results suggest that S-line dams allocated considerably more resources to maintenance of offspring than C-line dams. This was insufficient to provide the offspring with an adequate amount of resources, resulting in reduced pup development and increased pre-weaning mortality rates. 相似文献
33.
目的:探索硫氧还蛋白(Trx)抗体柱对Trx融合蛋白纯化的可行性。方法与结果:对含有Trx基因的质粒表达载体pTrxFus进行改造,在Trx读框之后加入6×His序列,并在大肠杆菌中表达C端带有6×His标签的Trx,经Ni2+柱亲和纯化后制备多克隆抗体;把经蛋白A纯化后的抗体偶联在溴化氰活化的琼脂糖凝胶上,制成Trx抗体柱;用此抗体柱纯化与Trx融合表达的豇豆胰蛋白酶抑制剂(CpTI),SDS-PAGE结果显示获得了纯度较高的Trx-CpTI。结论:用Trx抗体制成的免疫亲和层析柱可以有效纯化Trx融合蛋白。 相似文献
34.
Background
Classical bioconjugation strategies for generating antibody-functionalized nanoparticles are non-specific and typically result in heterogeneous compounds that can be compromised in activity. Expression systems based on self-cleavable intein domains allow the generation of recombinant proteins with a C-terminal thioester, providing a unique handle for site-specific conjugation using native chemical ligation (NCL). However, current methods to generate antibody fragments with C-terminal thioesters require cumbersome refolding procedures, effectively preventing application of NCL for antibody-mediated targeting and molecular imaging. 相似文献35.
36.
Jeroen Slikkerveer Pieter A Dijkmans Gertjan T Sieswerda Pieter AFM Doevendans Arie PJ van Dijk Freek WA Verheugt Thomas R Porter Otto Kamp 《Trials》2008,9(1):1-7
Background
The CONSORT Statement provides recommendations for reporting randomized controlled trials. We assessed the extent to which leading medical journals that publish reports of randomized trials incorporate the CONSORT recommendations into their journal and editorial processes.Methods
This article reports on two observational studies. Study 1: We examined the online version of 'Instructions to Authors' for 165 high impact factor medical journals and extracted all text mentioning the CONSORT Statement or CONSORT extension papers. Any mention of the International Committee of Medical Journal Editors (ICMJE) or clinical trial registration were also sought and extracted. Study 2: We surveyed the editor-in-chief, or editorial office, for each of the 165 journals about their journal's endorsement of CONSORT recommendations and its incorporation into their editorial and peer-review processes.Results
Study 1: Thirty-eight percent (62/165) of journals mentioned the CONSORT Statement in their online 'Instructions to Authors'; of these 37% (23/62) stated this was a requirement, 63% (39/62) were less clear in their recommendations. Very few journals mentioned the CONSORT extension papers. Journals that referred to CONSORT were more likely to refer to ICMJE guidelines (RR 2.16; 95% CI 1.51 to 3.08) and clinical trial registration (RR 3.67; 95% CI 2.36 to 5.71) than those journals which did not. Study 2: Thirty-nine percent (64/165) of journals responded to the on-line survey, the majority were journal editors. Eighty-eight percent (50/57) of journals recommended authors comply with the CONSORT Statement; 62% (35/56) said they would require this. Forty-one percent (22/53) reported incorporating CONSORT into their peer-review process and 47% (25/53) into their editorial process. Eighty-one percent (47/58) reported including CONSORT in their 'Instructions to Authors' although there was some inconsistency when cross checking information on the journal's website. Sixty-nine percent (31/45) of journals recommended authors comply with the CONSORT extension for cluster trials, 60% (27/45) for harms and 42% (19/45) for non-inferiority and equivalence trials. Few journals mentioned these extensions in their 'Instructions to Authors'.Conclusion
Journals should be more explicit in their recommendations and expectations of authors regarding the CONSORT Statement and related CONSORT extensions papers. 相似文献37.
Grass was field-dried to 3 different dry matter (DM) levels (200, 430 and 540 g/kg) and inoculated with 106–107 cfu/g of a Listeria monocytogenes strain sharing a phagovar occasionally involved in food-borne outbreaks of listeriosis. Formic acid (3 ml/kg) or lactic acid
bacteria (8·105/g) with cellulolytic enzymes were applied only to forages with low and intermediate DM levels. Forages were ensiled in laboratory
silos (1700 ml) and were stored at 25°C for 30 or 90 days. After 90 days of storage, L. monocytogenes could not be detected in any silo, except one with the high dry matter grass without additive. After 30 days of storage,
between 102 and 106 cfu L. monocytogenes/g silage were isolated from the untreated silages. Increasing the DM content from 200 to 540 g/kg did not reduce listeria
counts possibly because of the lower production of fermentation acids (higher pH). In silages treated with additives, counts
of L. monocytogenes were always lower than in silages without additive. In wet silages (DM 200 g/kg) both additives were effective, but in the
wilted silages (DM 430 g/kg) only the bacterial additive reduced listeria counts below detection level. Listeria counts were
highly correlated to silage pH (r = 0.92), the concentration of lactic acid (r = -0.80) and the pooled amount of undissociated
acids (r = -0.83). 相似文献
38.
Summary Endopolyploidy, which arises through the duplication of DNA without accompanying nuclear division, occurs in large numbers of lower and higher plants and animals, including the best known, the salivary gland nuclei of Drosophila. Endomitosis is one of the processes leading to endopolyploidy, in which the stages of mitosis (prophase, metaphase, anaphase) take place inside the nuclear membrane and without spindle formation. In mammals, endomitosis has been observed in the trophoblast of the placenta of the mouse, rat and rabbit. This is the first report of endomitosis in a normal human tissue, the trophoblast of first trimester human placenta.This research was supported in part by the Foundation for Reproductive Research and Education, Inc., Northwestern University, Department of Obstetrics and Gynecology. 相似文献
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