首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 140 毫秒
1.
2.
3.
《Autophagy》2013,9(4):549-551
When an autophagosome or an amphisome fuse with a lysosome, the resulting compartment is referred to as an autolysosome. Some people writing papers on the topic of autophagy use the terms “autolysosome” and “autophagolysosome” interchangeably. We contend that these words should be used to denote 2 different compartments, and that it is worthwhile maintaining this distinction—the autophagolysosome has a particular origin in the process of xenophagy that makes it distinct from an autolysosome.  相似文献   

4.
When an autophagosome or an amphisome fuse with a lysosome, the resulting compartment is referred to as an autolysosome. Some people writing papers on the topic of autophagy use the terms “autolysosome” and “autophagolysosome” interchangeably. We contend that these words should be used to denote 2 different compartments, and that it is worthwhile maintaining this distinction—the autophagolysosome has a particular origin in the process of xenophagy that makes it distinct from an autolysosome.  相似文献   

5.
Many health effects can be attributed to the Mediterranean herb oregano (Origanum vulgare L.) and several studies demonstrated the improving effect on performance, changes in blood count, antibacterial, antifungal and immunmodulating abilities. The majority of these investigations were carried out with processed essential oil, while whole plant material was only used in a few studies. Thus, the aim of the present experiment was to test the effect of increasing proportions of dried oregano in piglet feed on health and performance, with a special focus on immune modulation. A total of 80 male castrated weaned piglets (body weight [BW] 7.9 kg ±1.0 kg) were used in a feeding experiment lasting 5 weeks. They were assigned to 4 experimental groups: a control diet, and three diets with an oregano supplementation at 2 g, 4 g and 8 g per kg feed, respectively, corresponding to 23.5 mg, 46.9 mg and 93.9 mg carvacrol/kg DM. After 3 weeks, half of each group was challenged with 5 µg lipopolysaccharides (LPS) per kg BW. Blood samples were collected 2 h after LPS stimulation and analysed for T-cell phenotypes, granulocyte activity, clinical-chemistry as well as white and red blood count. The results indicate no effects of oregano on performance. In contrast, oregano altered the lymphocyte proportion and the ratio of CD4+ and CD8+ T-cells as well as the triglyceride concentration in the serum of non-stimulated and in LPS-stimulated piglets. In conclusion, whole plant supplementation of oregano to piglet feed altered immune-related parameters, but did not modulate the acute inflammatory response induced by LPS stimulation.  相似文献   

6.
The objective of the present study was to investigate physiological effects of a marginal copper and iron supply on pigs. Therefore an experiment was conducted with 4 × 12 growing pigs of the crossbreed Pietrain × Deutsche Landrasse. The animals were fed for a period of 119 days with a diet poor of copper (1.5 mg Cu/kg diet) and/or poor of iron (35 mg Fe/kg diet). Control animals were supplied adequately with copper (4.8 mg Cu/kg diet) and iron (85 mg Fe/kg diet). The diet was given according to weight. After reaching an average weight of 102.6 ± 3.5 kg the animals were slaughtered. Due to the activity of the coerulplasmin and katalase enzyme and the haematological parameters, the supply of copper and iron could be classified as marginal. There was no interaction between copper deficiency and iron metabolism. The protein metabolism was unchanged. Low copper intake reduced the copper concentrations in serum, liver, muscle and backfat, and low iron intake reduced the iron concentration in serum, liver and muscle. Marginal copper and iron supply had no relevant effect on either food intake and growth performance or carcass characteristics and meat quality.  相似文献   

7.
Beyond the energy requirement of maintenance, the assimilated energy, occurring in bioproducts, is linearly proportional to the intake of metabolizable energy in non‐underfed conditions. In contrast, resting metabolic rate is differing between individuals within a population of an animal species. As adaptability to changed environmental conditions may play a role, young bulls were exposed to thermoneutral (18°C) and low (4°C) ambient temperatures and were fed at two feeding levels (1.0 and 1.6 times energy requirement in maintenance) to produce metabolic rate differences, using the same animals, metabolic rate was altered by reducing the sympathetic outflow in each case. Expression of sulfonylurea receptors in circulating mononuclear leukocytes and cells from skeletal muscle (m. semitendinosus) was studied by flow cytom‐etry. Changes of metabolic rate at rest corresponded to the portion of cells with sulfonylurea receptors expression. The data from reducing the sympathetic outflow and those from sulfonylurea receptors expression are useful to explain metabolic rate differences among individuals of an animal population.  相似文献   

8.
Barley, probably the oldest cultivated cereal, is widely grown in cooler areas of the world. The annual world production of nearly two and a half billion bushels exceeds that of rye but is less than that of rice, wheat, corn and oats, respectively. Most of the annual 300 million dollar crop of the U.S. is fed to livestock, but about one- third is manufactured into malt.  相似文献   

9.
Liu YX 《生理科学进展》2005,36(2):97-101
刘以训教授是我国著名的生物学家,中国科学院院士。他致力于生殖生物学研究,在排卵、黄体萎缩、精子发生和胚胎植入等系列研究上,成绩卓著,享有国际声誉。读罢此文,钦敬之情油然而生。  相似文献   

10.
Stereocontrol in bakers' yeast reduction can be achieved by introduction of a sulfur functional group into substrates. α-Methylthio-β-keto esters are reduced to give exclusively (3S)-3-hydroxy esters. α-Substituted β-keto thiol esters and dithioesters afford (2R,3S)-3-hydroxy esters with high diastereo-and enantioselectivity. Ketones possessing 1,3-dithiane, phenylsulfenyl, or phenylsulfonyl groups at the α-position are transformed also into the corresponding (S)-secondary alcohols. Optically pure (S)-(phenylsulfinyl)acetones can be obtained by kinetic resolution of racemic derivatives with the yeast. Diastereo- and enantioselective reduction of 1,2-diketones leading into (1S,2S)-1,2-diol derivatives can be also achieved by introduction of 1,3-dithiane, phenylsulfenyl or phenylsulfonyl groups into the α-position. Reductions of carbon-carbon double bond of sulfur-functionalized prenyl derivatives provide both chiral (R)- and (S)-C5-building blocks for terpenoid synthesis. The utility of the reduction products as chiral building blocks is demonstrated in the synthesis of biologically active natural products such as pheromones, sugars, antibiotics etc. by functional group transformation and carbon-carbon bond formation reactions with the aid of sulfur functional groups.  相似文献   

11.
Atomic absorption spectrometry is used to determine the contents of microelements (such as Zn, Cu, Ca, Mg and Fe) in the all-blood and hair of the Han, Uygur, and Kazak people in normal health state. The results show that the above mentioned elements in the hair arranged successively as Ca>Zn>Mg>Fe>Cu and those in the all-blood of the Han people arranged as Fe>Mg>Ca>Zn>Cu; of the Uygur and Kazak people, as Fe>Mg>Ca>Zn>Cu. This paper reports that the content of the microelement Mg in the all-blood and hair of the Uygur and Kazak people is obviously higher than that of the Han people (P<0.05).  相似文献   

12.
毛果苔草湿地营养元素的积累、分配及其生物循环特征   总被引:25,自引:2,他引:23  
何池全  赵魁义 《生态学报》2001,21(12):2074-2080
毛果苔草(Carex lasiocarpa)湿地地上部分积累量小于地下部分的积累量,在地上几个构件中,叶片比叶鞘积累量大,而穗的积累量最小;地下部分中细根比根茎的积累量大.土壤分室营养元素贮量在系统的各分室中占绝对优势,毛果苔草湿地土壤中各种营养元素总贮量的顺序为K>Fe>N>Ca>P>Mg>Mn>Zn>Cu;它们的吸收系数的排序是Mn>N>P>Zn>Mg>Cu>Ca>Fe>K;几种营养元素的利用系数的排序是Mn>N>P>Zn>Mg>Cu>Ca>Fe>K;几种营养元素的循环系数的排序为Ca>K>Mg>N>P>Mn>Zn>Cu>Fe;因此,该系统中钙、钾的存留比例最小,而流动性较大,而铁则相反,存留比例大,流动性较小.  相似文献   

13.
滇中常绿阔叶林及云南松林枯落物的初步研究   总被引:11,自引:0,他引:11  
刘文耀  荆贵芬  郑征   《广西植物》1989,9(4):347-355
本文以滇中高原为背景。研究了通海秀山常绿阔叶林及云南松林的凋落物的数量、组成、季节变化规律、营养元素(N、P、K、Ca、Mg、Cu、Mn、Fe)含量、以及林地枯枝落叶层的现量,研究结果表明滇中地区森林的年凋落量是较大的,营养元素含量及贮量也是丰富的。两类森存林的凋落规律相似,常绿阔叶林的凋落量、营养元素含量及其贮量都大于云南松林,但两类森林的枯枝落叶现存量则相接近,说明常绿阔叶林的物质循环周期较云南松林短。文章提出为了提高森林土壤肥力、加快生物循环过程,增加生物产量,要注意保存林地内还原于土壤中的所有凋落物。  相似文献   

14.
北京人工刺槐林化学元素含量特征   总被引:14,自引:0,他引:14       下载免费PDF全文
 31年生人工刺槐(Robinia pseudoacacia)林内各种植物的化学元素含量以C素最高,尤以刺槐树干中C含量多。N和Ca在刺槐叶片中含量大。丛生隐子草(Cleistogenes caespitosa)地上部分含K量高于林内其他植物。Fe在荆条(Vitex negundo var.heterophylla)叶片中含量较多。Al和Na在植物细根中含量为大。酸枣(Zizyphus jujuba var.spinosa) 叶中含有较高的Mg和Mn。 刺槐林的乔木、灌木、草本层化学元素积累量以C>Ca>N> K>Mg>P>Fe>Al>Na>Mn>Cu>Zn为序。灌木层化学元素积累量除C和Ca以外,均高于乔木层。对比地表枯枝落叶层化学元素总量与人工林元素的积累量,以Na的比值最高,Ca、Mn、Fe、Zn比值次之,元素归还量都较大。P比值较低,归还量较少。刺槐林土壤化学元素贮存量是以Ca>N>Mg>Fe>K>P>Na>Mn>Al>Zn>Cu为序。植物对土壤中化学元素的富集系数以K、Al和P较高。人工林元素积累量与土壤元素贮存量之比,亦以K、P、Al比值较高。可见土壤中的K、P和Al相对是不足的。  相似文献   

15.
The concentrations of nine mineral elements were determined by atomic absorption spectroscopy in Gentiana rigescens from three zones (middle, southeast, and northwest zones) of Yunnan province in China. The average concentrations of mineral elements were found in the order K>Ca>Mg>Fe>Na>Zn>Cu>Cr>Se. Samples collected from the middle zone of Yunnan were enriched in Na (242.24 ± 50.80 mg/kg) and Mg (959.78 ± 54.60 mg/kg). However, materials from the southeast zone were particularly enriched in Ca (3,448.70 ± 749.82 mg/kg), but depleted in Se. Whereas those from the northwest zone were plentiful of K (2,746.89 ± 84.84 mg/kg), Fe (923.06 ± 127.52 mg/kg), Zn (261.38 ± 53.05 mg/kg), Cu (110.08 ± 46.23 mg/kg), and Se (53.99 ± 22.38 mg/kg).  相似文献   

16.
Summary The binding of metals by cell walls isolated from Cunninghamella blakesleeana grown in the presence of inhibitory concentration of Cu or Co and which had altered chemical compositions was compared with the binding by control cell walls. The Co-cell walls, which had higher contents of phosphate and chitosan, bound more Cu and Co. Although the V max for Cu and Co differed with each of the cell walls, the K m values for the binding of Cu (6.3x10-3 M) and Co (2.1x10-3 M) were the same for all three types of cell walls. The cell walls also differed in their quantitative binding of various metals; control cell walls: Zn> Fe> Mn> Cd> Ca> Ni> Cu> Ag> Co> Mg; Cu-cellwalls: Zn> Fe> Mn> Cu> Ni> Cd> Ag> Ca> Co> Mg; and Co-cell walls: Fe> Zn> Cu> Mn> Cd> Ag> Ca> Ni=Co> Mg. The binding of Cu was temperature-dependent and had an optimum pH. The binding of Co was inhibited by Cu, but the binding of Cu was not inhibited by Co, and Cd totally suppressed the binding of Co but not of Cu, suggesting two binding sites on the cell walls, one exclusively for Cu and the other common to both metals but with a higher affinity for Co. The cell walls did not bind Mg. The Cu-or Co-loaded cell walls eluted with 5 mM ethylenediaminetetraacetate (EDTA) rebound these metals to the same or greater extent as the original walls, but walls eluted with 0.5 N HCl bound only 50% of that bound originally.  相似文献   

17.
水稻籽粒矿质元素含量遗传及主要农艺性状相关性分析   总被引:2,自引:0,他引:2  
通过了解水稻子粒钙、镁、铜、铁、锌和硒等矿质元素含量,以绿旱1号作为父本与102S、KD36S、7HS012及7HS013不育系为母本进行配组,对父本与杂交后代主要农艺及经济性状、水稻子粒中的矿质元素含量进行了遗传分析,并对各杂交后代的主要农艺性状和子粒中矿质元素含量以及各矿质元素含量间进行了相关性分析.结果表明,杂交后代农艺及经济性状多数表现出超高亲分离现象,且LK3的农艺及经济性状均表现为最好.水稻子粒矿质元素含量与部分农艺和经济性状存在明显的正相关或负相关关系,且K、Mg、Zn、Se等元素含量与水稻产量密切相关.水稻子粒中矿质元素含量大小依次为P>K >Mg >S> Ca> Mn >Fe >Zn >Cu >Se,4个杂交后代的K元素含量表现出超高亲分离现象,LK2、LK3和LK4的Fe元素含量也表现出超高亲分离现象.水稻子粒大量与微量元素之间相关性最高,微量元素之间相关性次之,大量元素之间相关性最小,以7HS012不育系为母本得到的杂交后代农艺性状表现较好,矿质元素含量最高,7HS013次之,其他不育系表现一般.本研究为选育出耐旱及营养价值高的水稻新品种母本的选择提供了理论依据.  相似文献   

18.
曹新  张思仲 《人类学学报》1996,15(3):255-259
应用核仁组织区银染技术对维吾尔、哈萨克及汉族共90人的染色体银染核仁形成区(Ag-Nucleolar Organizing Region,Ag-NOR)频率和近端着丝粒染色体随体联合频率的研究发现:维吾尔、哈萨克群体Ag-NOR及随体联合的细胞数与次数均高于汉族群体(P<0.01),具有显著性差异。维吾尔、哈萨克群体间上述的频率无显著性差异(P>0.05),支持了两民族遗传上的相近性。这与民族起源和过去用民族学、人类学研究结果是一致的。  相似文献   

19.
Summary The influence of community and edaphic variables on tissue nutrient concentration was assessed for seven species on aCarex wetland in southern Quebec, Canada.Potassium and sodium tissue levels were considerably higher and Ca and Mg 35% lower than in a deciduous forest. Macronutrient concentrations decreased in the order K>N>Ca>Mg>Na>P. Micronutrient concentrations (Fe>Mn>Zn>Cu) ranged from 0.038–0.005 mg/g. This was 2–3 times less abundant than in an adjacentScirpus wetland. Inter-species coefficient of variation in N, P and K was low (14%) compared to variation in Ca, Mg, and the micronutrients (35%).Principal components analysis of interrelations between tissue elements indicated a clear distinction between N, P, K, Cu, Mn, and Zn levels and ash, Ca, Mg, Na, and Fe levels on the first component. This difference related closely to water depth and fire incidence. The coincidence of burning with water depth and the period of maximum snowmelt and runoff in the Spring suggested the loss of N, P, K, Cu, Mn and Zn by volotilization, runoff, or leaching.Stem density was the most important parameter influencing tissue N, P, and K concentrations whereas soil nitrogen levels were important in ash, Ca, and Mg concentrations. Water depth was the most important variable in the case of Cu, Fe, Mn, Na and Zn levels. Typha angustifolia had the highest level of total nutrients in green tissue,Carex lanuginosa the lowest. Principal components analysis indicated soil nitrogen, water depth, and soil potassium levels, in that order, were the three most important variables influencing the patterns of tissue element variation among species.Potassium and sodium levels in 1-year old litter were 11% and 0.4% compared to concentrations in green tissue. Iron and manganese, both subject to oxidation and adsorption to litter at the soil surface, were distinctly higher (2247% and 199%) in litter than green tissue. Concentrations of these and other elements in litter were consistent with results reported in literature and indicated litter was especially active as a site of cation exchange in the system.  相似文献   

20.
文冠果叶片养分元素含量的动态变化及再吸收特性   总被引:7,自引:1,他引:6  
阴黎明  王力华  刘波 《植物研究》2009,29(6):685-691
以文冠果叶片为试材,运用原子吸收光谱法分析了叶片养分元素含量的季节动态变化和再吸收效率。结果表明:N、P、K均呈下降趋势,是“稀释效应”和养分再吸收导致;Mg呈“单峰”曲线走势,与Mg的生理功能有关;Fe、Mn呈“V”字型走势,Cu呈“W”型,Zn呈“N”型,与树体吸收特性和不同的物候期有关。总体来看,养分元素含量顺序是:N>P>K>Mg>Fe>Zn>Mn>Cu,且不同时期又有所不同。大量元素之间存在显著的相关关系;微量元素间相关关系不显著(Fe、Zn除外),Fe与N显著负相关,与拮抗作用有关。C/N呈升高趋势,差异显著;N/P呈降低趋势,差别不大。养分再吸收效率由大到小的顺序是:Mg>N>K>P,差异显著。微量元素由于移动性较差,不能被再吸收。N、P、K、Mg养分再吸收效率反映了文冠果较高的养分保存能力和养分利用效率。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号