共查询到20条相似文献,搜索用时 31 毫秒
1.
在田间自然条件下,通过两年两季单独种植(非竞争)和混合种植(竞争)试验,分析比较抗真菌转基因水稻E121-2-1和E122-2-9与其非转基因受体亲本E32和常规稻粤香占在农艺性状、繁殖能力、花粉活力、种子活力、种子库持久力和自生性等适合度成分上的差异,评价抗真菌转基因水稻的生态适合度。结果表明,在竞争情形下,E121-2-1和E122-2-9的株高、千粒重和每穗总粒数在两年均显著降低或在其中一年显著降低,E121-2-1和E122-2-9农艺性状的竞争能力总体上低于E32和粤香占。E121-2-1和E122-2-9的净替代率在竞争态势下两年均呈下降趋势,其中E121-2-1在其中一年下降显著,而E32和粤香占的净替代率随不同年份升高或下降,但变化不显著。E121-2-1和E122-2-9的花粉萌发率、种子发芽势两年均显著低于E32和粤香占,种子发芽率和田间自生苗率在其中一年显著低于E32和粤香占,种子库持久力与E32和粤香占相比两年均无显著差异。只有E121-2-1和E122-2-9种子的休眠期两年均显著高于对照E32和粤香占。结果说明转四价抗真菌基因水稻E121-2-1和E122-2-9的生态适合度优势不强,其种群在自然界中的生存竞争和延续能力不会超越非转基因水稻。 相似文献
2.
A K Kolomi?tsev M M Kornilova L A Stechenko T P Kuftyreva 《Arkhiv anatomii, gistologii i émbriologii》1989,96(3):43-48
Fibrillar components of the thymus lobules have been studied in persons 9-73 years of age and in 11-30 month-old noninbred white rats. Beginning from 9-10 years of age, i. e. before the onset of age involution, in the medullary substance of the lobules argyrophil carcass is formed; it includes numerous microvessels. At the age of 30-40 years a part of argyrophil fibers is subjected to destruction. At the same time in the medullary substance adipocytes appear. Their increasing amount is accompanied with substitution of the medullary substance for adipose substance, while a part of the cortical substance is preserved. These data are confirmed, when the thymus in old animals is studied. Ultrastructural manifestations of extra- and intracellular destruction of fibers are noted in them, too. The dynamics of the fibrillar component changes in the thymus in different animal individuals is not the same and can serve as one of the criteria of its age involution. 相似文献
3.
Yasushi Suwazono Teruhiko Kido Hideaki Nakagawa Muneko Nishijo Ryumon Honda Etsuko Kobayashi 《Biomarkers》2013,18(2):77-81
We investigated the biological half-life of the urinary cadmium concentration (U-Cd) based on a 24-year follow-up study after cessation of cadmium exposure in a cadmium-polluted area. Spot urine samples were obtained from all inhabitants in this area in 1979, 1986, 1991, 1999 and 2003. Biological half-life was calculated in the inhabitants whose U-Cd was more than 5 μg?l?1 (9 men and 12 women) or 5 μg?g?1 creatinine (9 men and 19 women) using a one-compartment model. The estimated half-life and 95% confidence intervals were 13.6 years (9.0–28.2 years) and 13.9 years (9.6–25.6 years) for unadjusted U-Cd in men and women, respectively. For creatinine-adjusted U-Cd, they were 14.2 years (11.2–19.4 years) and 23.5 years (17.7–35.0 years) in men and women, respectively. The biological half-lives of U-Cd obtained in this study were identical with the values of total body burden determined by a different method. 相似文献
4.
Hacihanefioğlu S Güven GS Deviren A Silahtaroğlu AN Yosunvkaya Fenerci E Ozkiliç A Yüksel A 《Genetic counseling (Geneva, Switzerland)》2002,13(1):41-48
We report an eleven years old boy and his fourteen years old brother who both have trisomy 9p syndrome. Their cytogenetic analysis using GTL-banding showed 46,XY,der(22)add(22)(p11) karyotype. Cytogenetic analysis of their mother and sister revealed a karyogram designated as 46,XX,t(9;22) (9pter-->9p12::22p11-->22qter). With the help of FISH technique, the derivative chromosome in the proband was further confirmed to be a translocation chromosome 22 carrying the aforementioned segments from chromosome 9 which originated from a segregation event of a mother's balanced translocation. Regarding clinical aspects of our cases, both showed similar findings of 9p trisomy syndrome but low frontal hairline, circular placement of the hair around the face and scarce, inverted eyebrows, findings not previously mentioned in the literature. We conclude that these new clinical findings could be used in the clinical diagnosis of the 9p trisomy syndrome along with the other well-documented symptoms. 相似文献
5.
From 1967 to 1978 38 patients with polycythemia vera received a long term cytostatic chemotherapy. The results of 14 patients who were given Procarbacin (Natulan) during a mean treatment time of 9 1/2 years are communicated. Two patients showed secondary tumors after 9 or 11 years respectively. The advantages and disadvantages of the various therapeutic approaches in the management of polycythemia in the literature are discussed together with our own experiences. 相似文献
6.
G V Ni 《Parazitologiia》1982,16(6):452-456
A possible effect of a new epidemic nidus "age" on the virulence of Leishmania was studied. For a period of 9 years 16 strains were isolated from man affected with leishmaniosis. Infectivity of all strains was high (100% infection of animals). The incubative period of the disease in animals was the shorter the more years passed from the moment of the nidus formation. Strains isolated within the first 4-5 years caused leishmaniosis in 2-3 months and those isolated during subsequent years--in 1 to 3 weeks. 相似文献
7.
在糖尿病足患者溃疡创面分泌物中,基质金属蛋白酶9 (matrix metalloproteinase-9,MMP-9)过高是预测糖尿病足的发生及足溃疡难愈的主要指标,其可能的机制包括:高水平MMP-9降低VEGF的表达、抑制成纤维细胞的生物学行为影响糖尿病足溃疡愈合;失衡的MMP-9/TIMP-1比值影响糖尿病足溃疡愈合。选择性MMP-9抑制剂(包括小分子抑制剂、高级伤口辅料抑制剂、基于干扰基因水平表达的RNA抑制剂)可以作为促进糖尿病足溃疡愈合的手段,但仍需大样本、多中心随机对照试验以及长期随访进一步验证其疗效及安全性。现查阅近年来涉及MMP-9和糖尿病足溃疡相关的文献,综述MMP-9对糖尿病足溃疡愈合的影响及其机制研究进展。 相似文献
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Gas composition of the arterial and venous blood and the oxyhemoglobin dissociation curve were determined before and after 20 minutes of oxygen inhalation in 9 apparently healthy subjects aged 60 to 74 years and in 9 young subjects aged 19 to 32 years. In hyperoxia of younger subjects, there was a shift to the left of both the oxyhemoglobin dissociation curve of the native blood and standard dissociation curve (pH 7.4). In old age, the shift to the left of the standard dissociation curve due to hypoxia was quite negligible and statistically insignificant, whereas in the native blood it was entirely absent because of the increased blood PCO2 and associated Bohr effect. 相似文献
10.
《Somatosensory & motor research》2013,30(3):121-130
In the elderly, intact motor functions of the upper extremity are critical for the completion of activities of daily living. Many studies have provided insight into age-related changes in motor function. However, the precise nature and extent of motor impairments of the upper extremity remains unclear. In the current study we have modified two tasks to assess hand/digit function in both young and aged rhesus monkeys. We tested monkeys from 9 to 26 years of age on these tasks to determine the level of fine motor performance across the adult age range. Compared to young monkeys (9–12 years of age), aged monkeys (15–26 years of age) were mildly impaired on fine motor control of the digits. These findings are consistent with previous studies that have found age-related impairment in fine motor function. However, the magnitude and extent of impairment in the current study does differ from previous findings and is likely due to methodological differences in the degree of task complexity. 相似文献
11.
Relationship between bronchial hyperresponsiveness and impaired lung function after infantile asthma
Delacourt C Benoist MR Le Bourgeois M Waernessyckle S Rufin P Brouard JJ de Blic J Scheinmann P 《PloS one》2007,2(11):e1180
Wheezing during infancy has been linked to early loss of pulmonary function. We prospectively investigated the relation between bronchial hyperresponsiveness (BHR) and progressive impairment of pulmonary function in a cohort of asthmatic infants followed until age 9 years. We studied 129 infants who had had at least three episodes of wheezing. Physical examinations, baseline lung function tests and methacholine challenge tests were scheduled at ages 16 months and 5, 7 and 9 years. Eighty-three children completed follow-up. Twenty-four (29%) infants had wheezing that persisted at 9 years of age. Clinical outcome at age 9 years was significantly predicted by symptoms at 5 years of age and by parental atopy. Specific airway resistance (sRaw) was altered in persistent wheezers as early as 5 years of age, and did not change thereafter. Ninety-five per cent of the children still responded to methacholine at the end of follow-up. The degree of BHR at 9 years was significantly related to current clinical status, baseline lung function, and parental atopy. BHR at 16 months and 5 years of age did not predict persistent wheezing between 5 and 9 years of age, or the final degree of BHR, but it did predict altered lung function. Wheezing that persists from infancy to 9 years of age is associated with BHR and to impaired lung function. BHR itself is predictive of impaired lung function in children, strongly pointing to early airway remodeling in infantile asthma. 相似文献
12.
V I Vlasov A I Novikov B A Zamotin 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1982,(5):26-30
Different forms of dysentery, especially those caused by Sh. sonnei and Sh. flexneri, have been found to differ considerably in their cyclic recurrence. The development cycles of the epidemic processes of dysentery have an objective character, occur in the presence of any tendencies in the morbidity rate, and depend on the natural factors. Thus, the cycles of increase and decrease in morbidity are 3, 6, 9, 12 years for dysentery caused by Sh. sonnei and 6, 7, 8 years for dysentery caused by Sh. flexneri. 相似文献
13.
The development of skill of children in the performance of a family computer game (Super Mario Brothers) was investigated among three groups of different age: kindergarten children (6 years old) and primary school children (9 and 12 years old). The skill to perform the game with either hand was evaluated by the mean scores gained by the children. In the normal (right and dominant) situation, the mean score improved significantly with advancement of age. Similar was true in the reversed (left hand dominant) situation, but more distinctly. The mean scores were significantly higher in the normal than in the reversed situations. The experienced children were superior to the inexperienced children in playing the game. The correlation between the reaction time and the game score was also investigated with the same subjects for the 9- and 12-year-old school children. Almost no correlation could be elucidated. 相似文献
14.
G G Gasanov A R Allakhverdiev Iu A Khorunzheva G D Velieva A I Nikiforov 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》1987,37(1):38-45
The present paper deals with age characteristics of EEG reactions, at the level of integral cues, to functional loads in children of 7-14 years and juveniles. Modelling of tense and emotional states leads to a reconstruction of the organization of the EEG of quiet waking state, with formation of integral characteristics specific for these states and reflecting various mechanisms of the brain activity. At the age of 9-12 years emotional loads bring about disturbances of EEG integral characteristics, testifying to a lowering of brain reactivity. 相似文献
15.
为在斑马鱼中获得特异且高效的基因敲除,多个实验室独立人工合成了序列彼此不一的Cas9 cDNA序列,并克隆入不同的体外转录载体。本文选取两种斑马鱼密码子优化的Cas9编码序列(zCas9_bz和zCas9_wc),对斑马鱼胚胎中的7个基因(外源egfp及内源chd、hbegfa、th、eef1a1b、tyr、tcf7l1a)分别进行敲除,通过PCR产物测序、克隆测序和表型分析比较了两种Cas9的敲除效率。结果发现,zCas9_wc在各种情况下都显现出较高的敲除效率,而zCas9_bz的效率相对较低。 相似文献
16.
Samples of Gammarus pulex and dace, Leuciscus leuciscus , taken from the River Avon, Hampshire, at intervals over a period of 9 years were examined for the presence of the acanthocephalan. Pomphorhynchus laevis. Changes in the incidence and intensity of infection of P. laevis in dace and in G. pulex and in the frequency distribution of P. laevis in dace were used as indicators of the population size of the parasite. Throughout the period of observation, the parasite showed a similar pattern of distribution along the length of the river, although at some sites its abundance varied from year to year. Levels of both incidence and intensity of infection of P. laevis in both hosts at one specific locality remained fairly constant over the 9-year period, and the annual variations fell within the natural range of monthly variation over any 12-month period. The frequency distribution of P. laevis in dace also exhibited a similar pattern throughout the period. It was thus concluded that the population size of P. laevis had not changed to any great extent over the 9 years. The factors responsible for this constancy are discussed in the light of conclusions drawn from earlier work. 相似文献
17.
ROBERT S. SOMMER UWE FRITZ HEIKKI SEPPÄ JONAS EKSTRÖM ARNE PERSSON RONNIE LILJEGREN 《Global Change Biology》2011,17(6):2049-2053
Faunal communities have been shaped in different ways by past climatic change. The impact of the termination of the last Glacial and the onset of the present (Holocene) Interglacial on large‐scale faunal shifts, extinction dynamics and gene pools of species are of special interest in natural sciences. A general pattern of climate‐triggered range expansion and local extinction of vertebrate species is known for Europe, and shows that in the modern temperate zone the main faunal change took place mainly during the Late Glacial (14 700–11 700 years ago) and Early Holocene (11 700–9 100 years ago). Based on large datasets of new radiocarbon data, we present precise temporal dynamics of climate‐driven disappearance and appearance of reindeer and pond turtle in southern Sweden. These two species are significant climate indicators in Late Quaternary biostratigraphy. Our data reveal that the reindeer disappeared from southern Sweden ca. 10 300 years ago, whereas the pond turtle colonized the area ca. 9 860 years ago, with a 450‐year gap between each species. This provides evidence for a sudden environmental turnover, causing the replacement of an arctic faunal element by a thermophilic species. The postglacial range dynamics of pond turtle and reindeer are a unique model case, allowing insights into the faunal turnover of other vertebrates during the last dramatic natural global warming event at the Pleistocene–Holocene transition. 相似文献
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19.
J. A. Sulikowski A. M. Cicia J. R. Kneebone L. J. Natanson P. C. W. Tsang 《Journal of fish biology》2009,75(10):2832-2838
Age and size at sexual maturity was determined for 185 male and 96 female smooth skates Malacoraja senta (ranging in size from 370 to 680 mm total length LT), collected from the western Gulf of Maine. Maturity ogives for males, based on clasper length, testis mass and the proportion of mature spermatocysts in the testes, suggest that 50% maturity occurs between 9 and 10 years and 560 mm LT. Maturity ogives for females, based on ovary mass, shell‐gland mass and maximum follicle size, suggest that 50% maturity occurs at age 9 years and 540 mm LT. 相似文献
20.
黄土高原退耕地的生态恢复 总被引:57,自引:7,他引:50
在刈割干扰下,黄土高原退耕地恢复进程中植被从沙蓬(Agriophyllum arenarium)单优群落向以达乌里胡枝子(Lespedeza davurica)为优势种的群落演替。物种增加速度初期快,后期慢,退耕后恢复初期的新增物种主要是沙蓬和白草(Pennisetum flaccidum);中前期主要是茵陈蒿(Artemisia capillaris),可成为群落的次优势种;中后期新增物种主要是多年生豆科植物,只是群落的伴生种,群落中1年生和多年生植物地上生物量分别以8.8%的年平均速率减少或增加,豆科植物地上生物量及所占比例上升,在退耕地恢复过程中,上层土壤中植物地下生物量比例与变化幅度增加,表现出浅层化趋势,退耕地恢复演替1-7年,土壤粘粒和粉粒减少,砂粒增加,7年后变化趋势相反,退耕地0-100cm土壤含水量在恢复期间呈逐渐上升趋势,中期增幅显著,全N和速效N在恢复前期减少,后期增加,在刈割利用下,退耕地恢复过程中土壤全P,速效P和有机C持续衰竭,退耕地恢复到当前稳定的群落所需时间分别为优势种群8-9年,群落9-11年和土壤11-12年。 相似文献