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1.
云杉针叶的扫描电镜观察   总被引:3,自引:1,他引:2  
本文应用扫描电子显微镜,对针叶树云杉的针叶进行了表面结构的观察。结果表明,云杉针叶表面有较厚的角质层,角质层呈条纹状排列。从横切面上看,针叶为四角形,叶的四面均有气孔。云杉的气孔下陷,呈蜂窝状,叶表皮具有瘤状突起物, 这些构造特征,都有利于减少植物体水分的散失。通过对云杉这些结构的观察研究。可以为它的品种改良提供依据。  相似文献   
2.
Breeding high-yielding and nutrient-efficient cultivars is one strategy to simultaneously resolve the problems of food security,resource shortage,and environmental pollution.However,the potential increased yield and reduction in fertilizer input achievable by using high-yielding and nutrient-efficient cultivars is unclear.In the present study,we evaluated the yield and nitrogen use efficiency(NUE) of 40 commercial maize hybrids at five locations in North and Northeast China in 2008 and 2009.The effect of interaction between genotype and nitrogen(N) input on maize yield was significant when the yield reduction under low-N treatment was 25%-60%.Based on the average yields achieved with high or low N application,the tested cultivars were classified into four types based on their NUE:efficient-efficient(EE) were efficient under both low and high N inputs,high-N efficient(HNE) under only high N input,low-N efficient(LNE) under only low N input,and nonefficient-nonefficient under neither low nor high N inputs.Under high N application,EE and HNE cultivars could potentially increase maize yield by 8%-10% and reduce N input by 16%-21%.Under low N application,LNE cultivars could potentially increase maize yield by 12%.We concluded that breeding for N-efficient cultivars is a feasible strategy to increase maize yield and/or reduce N input.  相似文献   
3.
裂褶菌F17在限氮培养基中对偶氮染料刚果红表现出较高的脱色能力。最佳脱色条件为:温度28℃、初始pH值4.5以及菌体摇瓶培养3d加入染料,染料浓度以100mg/L为宜。诱导因子藜芦醇、吐温80、土豆汁和松木屑的加入明显提高了脱色率,而叠氮化钠和氰化钾的加入对脱色有显著的抑制作用。酶活检测表明,裂褶菌F17在刚果红脱色过程中主要产生MnP,LiP活力很小,未检测到Lac。此外,刚果红的脱色率与累积MnP酶活具有良好的线性关系,相关系数为0.973。推测裂褶菌F17对刚果红脱色的主要降解酶为MnP。  相似文献   
4.
帕金森病的尿动力学表现及临床意义   总被引:1,自引:0,他引:1  
为了评估有持久膀胱排尿障碍的帕金森氏病患者的尿动力学表现及其临床意义,对25例帕金森氏病患者行尿动力检查,并要求记录并回收24小时排尿日记.结果显示,1)有18例患者出现膀胱过度活动,逼尿肌收缩力低下或无反射4例,膀胱出口梗阻6例,另3例检查结果正常,无一例出现逼尿肌-括约肌协同失调; 2)患者所返回的排尿日记显示帕金森氏病患者普遍出现日排尿次数增加及每次排尿量的减少.由此可以得出结论:逼尿肌反射亢进是帕金森氏病患者尿动力学检查的最常见类型;尿动力学检查对正确处理帕金森氏病患者的排尿障碍有指导意义.  相似文献   
5.
INTRODUCTIONDNA replication is a fundamenial process thatmust occur only once at each ce1l cycle. This restrictcontrol appears to be achieved through the coordi-nated actiVities of numerous proteins. The buddingyeast Saccharompes cerevhaae provides an excellenteukaryotic model fOr study of proteins invo1ved inthe control of DNA replication.In the budding yeast, minichromosome mainte-nance (MCM) proteins, MCM2-7, are a family of strsequence-related proteins that play crucia1 roles inr…  相似文献   
6.
Schizophrenia is a serious neuropsychiatric illness affecting about 1% of the world’s population. Family, twin and adoption studies have demonstrated that 65%―85% of the susceptibility to schizophrenia can be attributed to genes. On the basis of genetic model-ing of epidemiological data and recent results of a number of whole-genome screens for susceptibility genes, schizophrenia has been considered a complex disorder. A number of genes with small to moderate effects are involved in combinat…  相似文献   
7.
The breakthrough development of induced pluripotent stem cells(iPSCs)raises the prospect of patient-specific treatment for many diseases through the replacement of affected cells.However,whether iPSC-derived functional cell lineages generate a deleterious immune response upon auto-transplantation remains unclear.In this study,we differentiated five human iPSC lines from skin fibroblasts and urine cells into neural progenitor cells(NPCs)and analyzed their immunogenicity.Through co-culture with autogenous peripheral blood mononuclear cells(PBMCs),we showed that both somatic cells and iPSC-derived NPCs do not stimulate significant autogenous PBMC proliferation.However,a significant immune reaction was detected when these cells were co-cultured with allogenous PBMCs.Furthermore,no significant expression of perforin or granzyme B was detected following stimulation of autogenous immune effector cells(CD3+CD8 T cells,CD3+CD8+T cells or CD3 CD56+NK cells)by NPCs in both PBMC and T cell co-culture systems.These results suggest that human iPSC-derived NPCs may not initiate an immune response in autogenous transplants,and thus set a base for further preclinical evaluation of human iPSCs.  相似文献   
8.
By nature,biomarker is the measurable change associated with a physiological or pathophysiological process.Unlike blood which has mechanisms to minimize changes and to keep the internal environment homeostatic,urine is more likely to reflect changes of the body and is a better biomarker source.Because of its potential in biomarker discovery,urinary proteins should be preserved comprehensively as the duration of the patients’corresponding medical records.Here,we propose a method to adsorb urinary proteins onto a membrane we named Urimem.This simple and inexpensive method requires minimal sample handling,uses no organic solvents,and is environmentally friendly.Urine samples were filtered through the membrane,and urinary proteins were adsorbed onto the membrane.The proteins on the membrane were dried and stored in a vacuum bag,which keeps the protein pattern faithfully preserved.The membrane may even permit storage at room temperature for weeks.Using this simple and inexpensive method,it is possible to begin preserving urine samples from all consenting people.Thus,medical research especially biomarker research can be conducted more economically.Even more objective large-scale prospective studies will be possible.This method has the potential to change the landscape of medical research and medical practice.  相似文献   
9.
用糜子蔗(sorghum×sugarcane)×millet sorghum茎尖愈伤组织为受体,通过基因枪轰击将Bar基因转入糜子蔗细胞;用除草剂Basta含量分别为1、2.5、5、10mg/L的8114诱导与分化培养基上选择抗性愈伤组织;在Bast a含量为1与1.5mg/L筛选培养基上,选择出3个快速增殖并大量再生绿苗的体细胞无性系(Clone),如BarC1、BarC2、BarC3;BarC1、C2再生植株用Basta含量为1、2.5-5mg/L的溶液进行抗性检测,证明这些小植株具有极强的抗性。 Abstract:The Bar genes were introduced into〔(sorghum×sugarcane) ×millet sorghum〕callus cells using particle bombardment.The callus were cultured on the 8114 media with Basta,the Bastas concentration is 1,2.5 and 5,10mg/L.3 Clones with regenerated capacity were screened out on the media with Basta 1,2.5mg/L,for example BarC1,BarC2,BarC3.The regenerated plant from BarC1、BarC2 were cultured on the solution with Basta 1.5,2.5,and 5mg/L,high resistance were obtained in these regenerated plants.  相似文献   
10.
中国四品种黄牛性染色体多态性的研究   总被引:31,自引:1,他引:30  
对4个地方黄牛品种(蒙古牛,秦川牛,岭南牛和西镇牛)共63头牛(37♂,26♀)染色体核型的比较研究表明,性染色体在品种间和品种内均存在多态性。Y染色体有中、亚中和近端着丝点染色体,其频率有一定的分布规律。X染色体均为一大的亚中着丝点染色体,但臂比和着丝点指数有品种差异。本文从性染色体多态性上揭示了中国黄牛起源的多元性,为中国黄牛品种的系统分类增添了又一新的依据和线索。  相似文献   
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