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1.
目的:探讨树鼩乳汁的基本成份,并和其它乳制品成份进行了比较分析。方法选取10只分娩后(1-21)d期间的哺乳期母树鼩,用人工被动母乳喂养方法让仔树鼩自由吮吸母乳,立即采用无菌操作的方法用注射器直接采取仔树鼩胃内的乳汁,1次/2 d,连续3-5次,每只母树鼩采取18 mL乳汁,按照国家标准的方法进行成分检测。结果树鼩乳汁总固形物为43.63%、脂肪为26.01%、蛋白质为10.41%、乳糖为0.45%、灰分为0.99%。树鼩乳的总固形物、灰分、蛋白质、脂肪、乳糖含量分别为牛乳的3.36、1.24、2.74、6.67、0.09倍;树鼩乳的总固形物、灰分、蛋白质、脂肪、乳糖含量分别为婴幼儿配方乳的1.44、0.20、0.58、1.53、0.06倍;与牛乳及婴幼儿配方乳矿物质成分含量相比,树鼩乳的矿物质成分钙、磷、钾、钠、镁、铁、锌含量均大于牛乳,分别为1.83、2.73、1.25、1.93、1.28、1.48倍,而均小于婴幼儿配方乳,分别为0.66、0.85、0.34、0.26、0.85、0.24、0.49倍。结论树鼩乳的主要营养成分呈现高脂高蛋白低糖的类型,可为树鼩人工育幼和饲养工作提供依据。  相似文献   

2.
20 0 2年 6月于云南省河口瑶族自治县采集到鱼类标本 3尾 ,经鉴定为我国华吸鳅属鱼类之新纪录种———红河华吸鳅 (Sinogastromyzonchapaensis)。测量标本 3尾均保存在台湾清华大学。体长 35~ 5 0mm。背鳍iii,8;臀鳍ii,5 ;胸鳍xiv~xv ,14~ 16 ;腹鳍x~xi,11~ 12。侧线鳞 6 0~ 6 4。体长为体高的 7 0~ 7 2倍 ,为体宽的 4 3~ 4 6倍 ,为头长的 4 9~ 5 1倍 ,为尾柄长的 5 4~ 6 0倍 ,为尾柄高的 12 7~ 14 0倍 ,为背鳍前距的 2 2倍 ,为腹鳍前距的 2 4~ 2 7倍。头长为头高的 1 8~ 1 9倍 ,为头宽的 0 9~ 1 1倍 ,为吻长的 2 0~2 1倍 ,为眼径的 4 7~ 5 0倍 ,为眼间距的 2 0~ 2 3倍。尾柄长为尾柄高的 2 2~ 2 6倍。头宽为口宽的 3 7~4 6倍。  相似文献   

3.
Paclobutrazol (PB), chlormequat (CM), fenarimol (FM), and gibberellin A3 (GA3) were applied as exogenous growth regulators once (1 × PB, 1 × CM, 1 × FM, 1 × GA3), twice (2 × PB, 2 × CM, 2 × FM, 2 × GA3) or three times (3 × PB, 3 × CM, 3 × FM, 3 × GA3) onto grafted grapevine rootlings of cv. Cardinal on Kober 5BB grown in nursery and in vegetative pots. Water was also applied at each application, at every 15 days, as the control (C). Application treatments 2 × PB and 3 × PB, as well as 2 × CM retarded shoot elongation and increased dry matter content in shoots. Treatments 3 × PB, 2 × CM and 3 × CM also significantly increased dry weight of roots in comparison to C. Repeated application of growth inhibitors (PB and CM) significantly increased starch content in shoots when compared to C as well as to GA3-treated plants. A very strong correlation existed between the shoot sugar: starch ratio (that was increased by 3 × CM and 2 × PB) and the percentage of first-grade graftlings. PB and CM significantly enhanced maturity (defined here as giving a high rate of survival and reduced post damage) of grapevine graftlings. This is a very important quality attribute for their use as planting material.  相似文献   

4.
The dynamics of the medium amino acid composition was studied during a 6-hour perfusion of dog kidney and liver by a mixture of autogenic plasma and medium 199 (a ratio of 2 : 3). In comparison to the initial level the amount of histidine during 6-hour cultivation of the kidney was found to increase 2.2 times, that of glutamic acid--1.7 times, and of alanine and lysine--1.6 times. At the same time the amount of arginine, serine and asparagic acid became 3.3 times and of glutamine and threonine--2.5 times lower. With the liver perfusion the level of glutaminic acid became 2.9 times, of alanine--2.3 times, of cystine--2 times and of glycine--1.5 times higher. With the liver perfusion the level of arginine decreased so rapidly that none was found in the medium after a 2-hour perfusion. The described method of amino acid analysis during the cultivation of the organs could serve as means for elaborating and correcting the culture media.  相似文献   

5.
In elaborating a model of the progress of an epidemic, it is necessary to make assumptions about the distributions of latency times and infectious times. In many models, the often implicit assumption is that these times are independent and exponentially distributed. We explore the effects of altering the distribution of latency and infectious times in a complex epidemic model with regional divisions connected by a travel intensity matrix. We show a delay in spread with more realistic latency times. More realistic infectiousness times lead to faster epidemics. The effects are similar but accentuated when compared to a purely homogeneous mixing model.  相似文献   

6.
压强温度耦合作用下小蛋白去折叠过程的分子动力学模拟   总被引:5,自引:0,他引:5  
在不同温度(280~540K)和压强(1×102~8×105 kPa)的耦合作用下,对GB1(the B1 domain of protein G)进行了56次独立分子动力学模拟,模拟时间达88.8 ns。在此基础上,研究了压强和温度对GB1去折叠过程的耦合效应。结果表明,压强对温度去折叠过程有明显影响,改变了蛋白质二级结构去折叠速度和蛋白质去折叠过程发生事件的先后次序。相同温度下,GB1的α-螺旋和β-折叠的稳定性随压强增大而提高;可及性表面积和其它结构特性参数随压强增大而减小。适度的压强(如2×105 kPa)会抑制温度导致的GB1二级结构去折叠速度,而更大的压强(如8×105 kPa)又加速了GB1的去折叠速度。在模拟的温度范围,当压强为100和2×105 kPa时,GB1疏水核协同暴露于水,而5×105和8×105 kPa时没出现此现象,这与最近的高压变性实验结果一致。  相似文献   

7.
Becker SI 《PloS one》2011,6(3):e17740
The present study examined the factors that determine the dwell times in a visual search task, that is, the duration the gaze remains fixated on an object. It has been suggested that an item's similarity to the search target should be an important determiner of dwell times, because dwell times are taken to reflect the time needed to reject the item as a distractor, and such discriminations are supposed to be harder the more similar an item is to the search target. In line with this similarity view, a previous study shows that, in search for a target ring of thin line-width, dwell times on thin linewidth Landolt C's distractors were longer than dwell times on Landolt C's with thick or medium linewidth. However, dwell times may have been longer on thin Landolt C's because the thin line-width made it harder to detect whether the stimuli had a gap or not. Thus, it is an open question whether dwell times on thin line-width distractors were longer because they were similar to the target or because the perceptual decision was more difficult. The present study de-coupled similarity from perceptual difficulty, by measuring dwell times on thin, medium and thick line-width distractors when the target had thin, medium or thick line-width. The results showed that dwell times were longer on target-similar than target-dissimilar stimuli across all target conditions and regardless of the line-width. It is concluded that prior findings of longer dwell times on thin linewidth-distractors can clearly be attributed to target similarity. As will be discussed towards the end, the finding of similarity effects on dwell times has important implications for current theories of visual search and eye movement control.  相似文献   

8.
Aflatoxin content and number of fungi in poultry feedstuffs from Indonesia   总被引:1,自引:1,他引:0  
The content of aflatoxin and associated fungi was determined in 56 samples, including 34 of corn, 10 of soybean meal, nine of rice bran and three of broken rice, collected from different poultry farms and poultry feedmills situated around Jakarta-Bogor, Indonesia.
Ninety-one per cent of the corn samples contained aflatoxins and the total concentration ranged from 22 to 6171 μ g/kg. With rice bran, 100% of the samples were positive for aflatoxin B1, ranging from 36 to 71 μ g/kg. No aflatoxin was detected in samples of soybean meal or broken rice. All the samples were contaminated by several fungi (8 times 103–5 times 106cfu/g) and further identification was limited to Aspergillus flavus and A. parasiticus. The dominant species was A. flavus (2 times 103–4 times 106cfu/g in corn samples, 1·0 times 103–1·0 times 105cfu/g in soybean meal, 2 times 104–4·4 times 105cfu/g in rice bran and 2 times 104–6 times 104cfu/g in broken rice). Some of the corn samples also contained A. parasiticus (2 times 103–9·5 times 104cfu/g).  相似文献   

9.
A note on generation times in epidemic models   总被引:1,自引:0,他引:1  
The time between the infection of a primary case and one of its secondary cases is called a generation time. The distribution (and mean) of the generation times is derived for a rather general class of epidemic models. The relation to assumptions on distributions of latency times and infectious times or more generally on random time varying infectiousness, is investigated. Serial times, defined as the times between occurrence of observable events in the progress of an infectious disease (e.g., the onset of clinical symptoms), are also considered.  相似文献   

10.
A modified version of Fisher''s tea tasting experiment was performed to test the confident assertions of some members of an academic surgical unit that they could easily distinguish malt from blend whisky. Eight male volunteers from the unit, divided into regular and inexperienced whisky drinkers, were blindfolded and given a glass of each of six whiskies. The whiskies included three malts and three blends, and each subject tasted each whisky six times. They were asked whether the whisky was malt or blended, whether they could identify the distillery, and whether they liked it (ranked on a nine-point scale). The four regular whisky drinkers identified the whiskies as malts 57 times, as blends 84 times, and did not know three times; the inexperienced drinkers identified them as malts 64 times, as blends 79 times, and did not know on one occasion. The regular drinkers correctly identified the malts 36 times and the blends 48 times, and the inexperienced drinkers correctly identified malts 30 times and blends 40 times. Statistical analysis of the data suggested that within the unit malt whisky could not be distinguished from blended whisky and that experience did not alter powers of discrimination. A surgeon with no discriminatory prowess at all could be expected to achieve complete discrimination of malt from blend whisky once in 2 occasions. These results suggest that, although "uisgebeatha" has unique properties, the inexpert drinker should choose his whisky to suit his taste and pocket and not his self image.  相似文献   

11.
All of 18 shrew moles, Neurotrichus gibbsii, collected in Oregon and Washington were infected with one or more species of coccidia. Three eimerians and one isosporan were identified and described as new species. Sporulated oocysts of Eimeria heterocapita n. sp. were subspheroid to ellipsoid, 25.5 times 21.4 (23–27 times 18–23) μm. A membranous, cap-like structure was present at one pole of the oocyst, but a micropyle, oocyst residuum, and polar body were absent. Ovoid sporocysts were 13.6 times 10.0 (12–15 times 9–11) μm; a compact sporocyst residuum was present, but Stieda, sub-, and parastieda bodies were absent. This species was found in 2 of 18 (11%) hosts. Sporulated oocysts of Eimeria neurotrichi n. sp. were avoid, 17.6 times 13.6 (16–20 times 11–16) μm; micropyle and oocyst residuum were absent, but a polar body was present. Ovoid sporocysts were 10.7 times 5.5 (9–12 times 5–6) μm; Stieda body and sporocyst residuum were present, but sub- and parastieda bodies were absent. This species was found in 2 of 18 (11%) hosts. Sporulated oocysts of Eimeria parastiedica n. sp. were subspheroid, 27.4 times 25.5 (25–30 times 22–28) μm; micropyle, oocyst residuum, and polar body were absent. Ovoid sporocysts, pointed at both ends, were 18.3 times 10.4 (16–20 times 9–11) μm; Stieda, sub-, and parastieda bodies were present as was a sporocyst residuum. This species was found in 2 of 18 (11%) hosts. Sporulated oocysts of Isospora neurotrichi n. sp. were subspheroid, 13.9 times 12.0 (11–16 times 10–15) μm; micropyle and oocyst residuum were absent, but 1–3 polar bodies were present. Ellipsoid sporocysts were 9.2 times 6.1 (8–11 times 5–8) μm; sub- and parastieda bodies were absent, but a Stieda body and sporocyst residuum were present. This species was found in 17 of 18 (94%) hosts. Ten of 18 (56%) hosts were seen to be naturally infected with only one coccidium.  相似文献   

12.
Influence of the antitumour rhenium-platinum system on biochemical liver characteristics in the model of tumor growth (Guerin carcinoma) was studied and possible hepatoprotective activity of rhenium cluster compounds when introducing them in different forms was shown, that was confirmed by decreasing of diagnostic enzymes activity in blood (aminotransferase--AST 6 times and ALT 5.6 times, lactatedehydrogenase 4.9 times, gamma-glutamyltranspeptidase 3.6 times) and normalization of morphological state of the liver cells. The hepatoprotective activity of the cluster rhenium compound with adamanthyl ligands was confirmed in the model of acute toxic hepatitis. Introduction of this compound led to reduction of the concentration of MDA in homogenates of liver tissue (2 times), and in blood plasma (3.8 times); to reduction of levels of diagnostic liver enzymes in blood--AST and ALT 5.8 and 5.5 times respectively in comparison with control group. Some aspects of the mechanism of hepatoprotection were discussed, that included the presence of conjugated systems around the quadrupol rhenium-rhenium bond and alkyl radicals with significant positive inductive effects.  相似文献   

13.
Chang SH 《Biometrics》2000,56(1):183-189
A longitudinal study is conducted to compare the process of particular disease between two groups. The process of the disease is monitored according to which of several ordered events occur. In the paper, the sojourn time between two successive events is considered as the outcome of interest. The group effects on the sojourn times of the multiple events are parameterized by scale changes in a semiparametric accelerated failure time model where the dependence structure among the multivariate sojourn times is unspecified. Suppose that the sojourn times are subject to dependent censoring and the censoring times are observed for all subjects. A log-rank-type estimating approach by rescaling the sojourn times and the dependent censoring times into the same distribution is constructed to estimate the group effects and the corresponding estimators are consistent and asymptotically normal. Without the dependent censoring, the independent censoring times in general are not available for the uncensored data. In order to complete the censoring information, pseudo-censoring times are generated from the corresponding nonparametrically estimated survival function in each group, and we can still obtained unbiased estimating functions for the group effects. A real application and a simulation study are conducted to illustrate the proposed methods.  相似文献   

14.
Although female insects generally gain reproductive benefits from mating frequently, females do not mate unlimited numbers of times. This study asks whether the limit on female mating rate is imposed by trade‐offs between reproduction and survival. Female Gryllus vocalis were given the opportunity to mate 5, 10, or 15 times with novel males, and the effects on daily fecundity (egg production), fertility (proportion of eggs that were fertilized), and female post‐experimental longevity were measured. Females that mated 10 times laid more eggs and had a higher proportion of fertile eggs than females that mated 5 times. However, females that mated 15 times did not lay significantly more eggs or have a higher proportion of fertile eggs than females that mated 10 times. Although number of matings did not affect the date that females laid their last egg, mating more times was associated with a prolonged period of laying fertile eggs. Number of matings did not affect female post‐experimental longevity. Thus, there was no trade‐off between female reproductive effort and survival, even when females mated very large numbers of times. When females were allowed to mate ad libitum, the average number of times that females mated was greater than the number of times that confers maximal fitness. The lack of cost to mating explains why females might be willing to mate beyond the point of diminishing reproductive returns.  相似文献   

15.
It is not known whether global warming will affect winning times in endurance events, and counterbalance improvements in race performances that have occurred over the past century. We examined a time series (1933–2004) from the Boston Marathon to test for an effect of warming on winning times by men and women. We found that warmer temperatures and headwinds on the day of the race slow winning times. However, 1.6°C warming in annual temperatures in Boston between 1933 and 2004 did not consistently slow winning times because of high variability in temperatures on race day. Starting times for the race changed to earlier in the day beginning in 2006, making it difficult to anticipate effects of future warming on winning times. However, our models indicate that if race starting times had not changed and average race day temperatures had warmed by 0.058°C/yr, a high-end estimate, we would have had a 95% chance of detecting a consistent slowing of winning marathon times by 2100. If average race day temperatures had warmed by 0.028°C/yr, a mid-range estimate, we would have had a 64% chance of detecting a consistent slowing of winning times by 2100.  相似文献   

16.
目的:比较诺和锐30每日2次和3次皮下注射的疗效和安全性。方法:为期3个月的随机、开放式试验,100例2型糖尿病(T2DM)患者随机分为诺和锐30皮下注射2次(每日早、晚餐前)、3次(早、中、晚餐前)组,观测两组患者空腹血糖(FPG),中餐前血糖,晚餐前血糖,睡前的血糖值以及糖化血红蛋白(HbA1c),低血糖事件及其他不良事件差异。结果:诺和锐30皮下注射3次组总体血糖水平低于2次组,低血糖事件和其他不良反应发生次数无显著性差异。结论:两组治疗方法均能有效地降低血糖,3次治疗组控制餐后血糖更具优势,HbA1c降低更好,未增加低血糖风险。  相似文献   

17.
The relative toxicity of pesticides to Phyllocnistis citrella and its parasitoid Ageniaspis citricola was compared by several bioassay methods. A clip-cage bioassay measured survival of adults exposed to fresh residues at 0.25-times (0.25×), 0.5×, 1×, and 2× the lowest recommended rate of each pesticide, a water control (0×), and 24- and 48-h aged residues of oil at 1.5% (1×) rate. A one-species cylinder bioassay determined the effects of pesticides on immature stages of the citrus leafminer after treating young citrus trees with the same rates of pesticides (except for avermectin, tested at 0×, 0.01×, 0.025×, 0.05×, 0.1×, and 0.25× rates). A sublethal rate of petroleum oil (0.4%) was added as an adjuvant in some treatments. The effect of pesticides on immature stages of A. citricola was determined with a two-species cylinder bioassay after treating young citrus trees with the same rates as above. An index of IPM compatibility was developed based on the efficacy of the pesticide as a control agent of the leafminer (or other pests) and its selectivity to the parasitoid at the lowest recommended field rate (0.25× the field rate for avermectin). Azadirachtin (Neemix) + oil, diflubenzuron (Micromite) + oil, fenoxycarb (Eclipse) + oil, and oil alone (FC 435-66) were classified as IPM-compatible insecticides. Sprays of azadirachtin (Align) + oil, neem oil (Neemgard), and drenched imidacloprid (Admire) were ranked as a semi-compatible insecticides. The fungicide copper hydroxide (Kocide 101) and a fish oil-based foliar fertilizer (Zapata HFE) were considered compatible. Avermectin (Agri-Mek) + oil, ethion (Ethion), and imidacloprid (Provado) applied as a spray were IPM-incompatible insecticides. These products should be tested under field conditions to confirm these ratings.  相似文献   

18.
The proliferation kinetics of a cultured hepatoma cell line, HTC, was studied by time-lapse photography and autoradiography. Variability of G1 phase, S phase and intermitotic times of sister cells were compared with data on the variability of G1 phase, G2 phase, S phase and intermitotic times of unrelated cells. Evidence is presented that the variation in times spent in intermitosis by a pair of sisters is determined by the variation of G2 phase durations, while the variation in intermitotic times of unrelated cells is mainly determined by the variation of G1 phase times.  相似文献   

19.
目的:探讨儿童化学发光免疫分析中标本量过少时,用怎样的稀释介质以及稀释方法解决这个问题,分析不同的稀释介质产生的基质效应。方法:本实验以儿童常规筛查检测项目血清三碘甲状腺原氨酸(TT3)为例,选取血清样本30例,分别使用美国贝克曼库尔特公司UniCelDX1800Access化学发光免疫分析仪测试药盒三碘甲状腺原氨酸(TT3)配套TT3定标液s0(简称TT3S0)、0.9%氯化钠、医用蒸馏水作为稀释介质进行手工2倍(1:1)及4倍(1:3)后测定。计算稀释测定结果与原始数据的差异,观察基质效应对检测结果的影响。寻找实际工作中可运用的稀释介质和稀释倍数。结果:不同稀释组与原始值之间比较,TT3S02倍(t=-0.7937,P〉0.05)、4倍稀释(t=-0.2503,P〉0.05),以及蒸馏水2倍稀释(t=-0.2845,P〉0.05)差异均无统计学意义。而0.9%氯化钠2倍(t=-6.4686,P〈0.05)、4倍稀释(t=-3.9842,P〈0.05),以及医用蒸馏水4倍稀释(t=-1.9957,P〈0.05)差异有统计学意义。结论:三碘甲状腺原氨酸TT3S0定标液2倍,4倍稀释方法及医用蒸馏水2倍稀释方法均可以得到较为满意的结果。三碘甲状腺原氨酸(TT3)配套TT3定标液S0可用于标本2倍及4倍稀释。当定标液获取困难,蒸馏水2倍稀释同样可以运用。  相似文献   

20.
目的:探讨儿童化学发光免疫分析中标本量过少时,用怎样的稀释介质以及稀释方法解决这个问题,分析不同的稀释介质产生的基质效应。方法:本实验以儿童常规筛查检测项目血清三碘甲状腺原氨酸(TT3)为例,选取血清样本30例,分别使用美国贝克曼库尔特公司UniCel DXI800 Access化学发光免疫分析仪测试药盒三碘甲状腺原氨酸(TT3)配套TT3定标液S0(简称TT3S0)、0.9%氯化钠、医用蒸馏水作为稀释介质进行手工2倍(1:1)及4倍(1:3)后测定。计算稀释测定结果与原始数据的差异,观察基质效应对检测结果的影响。寻找实际工作中可运用的稀释介质和稀释倍数。结果:不同稀释组与原始值之间比较,TT3S02倍(t=0.7937,P0.05)、4倍稀释(t=-0.2503,P0.05),以及蒸馏水2倍稀释(t=-0.2845,P0.05)差异均无统计学意义。而0.9%氯化钠2倍(t=-6.4686,P0.05)、4倍稀释(t=-3.9842,P0.05),以及医用蒸馏水4倍稀释(t=-1.9957,P0.05)差异有统计学意义。结论:三碘甲状腺原氨酸TT3S0定标液2倍,4倍稀释方法及医用蒸馏水2倍稀释方法均可以得到较为满意的结果。三碘甲状腺原氨酸(TT3)配套TT3定标液S0可用于标本2倍及4倍稀释。当定标液获取困难,蒸馏水2倍稀释同样可以运用。  相似文献   

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