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121.
漓江河岸带枫杨群落主要木本植物种间联结与相关分析   总被引:2,自引:0,他引:2  
种间联结能够反映植物群落中物种间的关系和群落的稳定程度,对植被的恢复与重建、生物多样性保护等具有重要的意义和价值。为了解漓江河岸带枫杨群落的种间联结特征,基于2×2联列表,通过方差比率(VR)、χ~2检验、Pearson相关系数、Spearman秩相关系数检验及PCA排序等,对枫杨群落主要木本植物种间关联性进行定量分析和生态种组划分。结果表明:(1)乔木层、灌木层以及乔木和灌木层的总体种间关联性均呈不显著正联结,表明枫杨群落处于较稳定的阶段;(2)χ~2检验结果显示,绝大多数种对呈不显著关联,说明群落各种对间关联较弱,各物种间呈独立分布格局;(3)Pearson相关检验和Spearman秩相关检验发现各层次的显著率均较低,种间相关性不显著的种对占绝大部分,种间相关性不强;(4)χ~2检验、Pearson相关系数检验和Spearman秩相关系数检验结果虽具有一致性,但也存在一定的差异,Spearman秩相关系数检验更具灵敏性,结合3种方法使用效果更佳;(5)根据PCA排序和种间联结关系,将20个主要物种划分为4个生态种组。  相似文献   
122.
新菌——吉林链梭菌的分类学研究   总被引:1,自引:0,他引:1  
从7例阴道炎患者阴道分泌物分离出7株细菌,均具有相同的生物学特性,G-梭状菌,单、成对或链状。无荚膜,无芽抱,无鞭毛。兼性厌氧菌,在大气中培养不生长,在5%~10%CO2中或烛缸培养18~24h才能形成菌落,MacConkey培养基不生长,最适生长温度35℃-37℃。氧化酶阴性,接触酶阴性,不还原硝酸盐,发酵糖类(指示剂用溴甲酚紫),克氏双糖铁高层和斜面均发生产酸反应,七叶苷水解试验阳性,马尿酸盐水解试验阴性。经BiologMicrostationSystem自动化细菌鉴定系统检测无确定结果,DNAG+C含量为42.3mol%、16srRNA序列测定结果经计算机检索国际基因菌库EMBL和GenBank所有序列进行比较,表明该白与已知科、属亲缘关系较远,结合其表型特征,建议建立新属,命名为吉林链梭菌(Streptofusiagen.nov.Jilinasp.nov.)该菌已收藏在中国微生物菌种保藏中心CGMCCNO.0215T(T=typestrain).该菌16SrRNA片断已被国际基因库收录,接收号为U34365。  相似文献   
123.
对不同浓度的亚硒酸钠在体外对αA及β23晶体蛋白基因转录的影响作了初步的研究.结果发现,随着亚硒酸钠浓度的升高,αA基因的转录下降;而当亚硒酸钠浓度升至5×10-5 mol/L时,αA基因的转录又呈反跳性回升;提示αA晶体蛋白在晶体细胞内,至少应答于高浓度的硒,可能作为一种应激蛋白表达.而随着硒浓度的增加,β23基因的转录则呈现出先升后降的双相变化;提示一定浓度的硒可能借某种机制影响或改变晶体上皮细胞的分化状态.  相似文献   
124.
将5, 10, 15, 20-四-(3-甲氧基-4-羟基苯基)卟啉钴(CoTMHPP)修饰在玻碳电极表面,制备成对多巴胶等神经递质有高灵敏度响应的CoTMHPP修饰电极.电极具有灵敏度高、响应快、稳定性好等特点.电极响应时间小于10s,儿茶酚类化合物的检测浓度为10-6mol/L.  相似文献   
125.
126.
Xu  Haiying  Kan  Caixia  Wei  Jingjing  Ni  Yuan  Miao  Changzong  Wang  Changshun  Ke  Shanlin  Shi  Daning 《Plasmonics (Norwell, Mass.)》2016,11(6):1645-1652
Plasmonics - In this paper, Ag nanorods (AgNRs) with different aspect ratios (ARs) were prepared by a seed-mediated fast growth approach. The possible growth mechanism of Ag nanostructures was...  相似文献   
127.
128.

Objective

To evaluate the effects of age and the clinical response to neoadjuvant chemotherapy (NACT) in patients with cervical cancer who received neoadjuvant chemotherapy followed by radical surgery.

Methods

A total of 1,014 patients with advanced cervical cancer who received NACT followed by radical surgery were retrospectively selected. Patients were divided into young (aged ≤35 years, n = 177) and older (aged >35 years, n = 837) groups. We compared the short-term responses and survival rates between the groups. The five-year disease-free survival (DFS) and overall survival (OS) rates were stratified by age, NACT response, and FIGO stage.

Results

The overall response rate was 86.8% in the young group and 80.9% in the older group. The young patients had an earlier FIGO stage (P<0.001), a higher rate of adenocarcinoma (P = 0.022), and more lymph node metastasis (P = 0.033) than the older patients. The presence of adenocarcinoma as the histological type (P = 0.024) and positive lymph node metastasis (P<0.001) were identified as independent risk factors for survival. When stratified by age and clinical response, young patients with no response to NACT had a worse clinicopathological condition compared with the other subgroups. Compared with non-responders, responders to NACT had a higher five-year DFS rate (80.1% versus 71.8%; P = 0.019) and OS rate (82.6% versus 71.8%; P = 0.003) among the young patients but not among the older patients.

Conclusions

Responders to NACT aged 35 years or younger benefitted the most from NACT, while the young non-responders benefitted the least. Age might represent an important factor to consider when performing NACT in patients with cervical cancer.  相似文献   
129.
A novel yellow-green leaf mutant yellow-green leaf-1 (ygl-1) was isolated in self-pollinated progenies from the cross of maize inbred lines Ye478 and Yuanwu02. The mutant spontaneously showed yellow-green character throughout the lifespan. Meanwhile, the mutant reduced contents of chlorophyll and Car, arrested chloroplast development and lowered the capacity of photosynthesis compared with the wild-type Lx7226. Genetic analysis revealed that the mutant phenotype was controlled by a recessive nuclear gene. The ygl-1 locus was initially mapped to an interval of about 0.86 Mb in bin 1.01 on the short arm of chromosome 1 using 231 yellow-green leaf individuals of an F2 segregating population from ygl-1/Lx7226. Utilizing four new polymorphic SSR markers, the ygl-1 locus was narrowed down to a region of about 48 kb using 2930 and 2247 individuals of F2 and F3 mapping populations, respectively. Among the three predicted genes annotated within this 48 kb region, GRMZM2G007441, which was predicted to encode a cpSRP43 protein, had a 1-bp nucleotide deletion in the coding region of ygl-1 resulting in a frame shift mutation. Semi-quantitative RT-PCR analysis revealed that YGL-1 was constitutively expressed in all tested tissues and its expression level was not significantly affected in the ygl-1 mutant from early to mature stages, while light intensity regulated its expression both in the ygl-1 mutant and wild type seedlings. Furthermore, the mRNA levels of some genes involved in chloroplast development were affected in the six-week old ygl-1 plants. These findings suggested that YGL-1 plays an important role in chloroplast development of maize.  相似文献   
130.
从甲型肝炎病毒(HAV)持续感染的BGMK细胞中提取高纯度的HAV,病毒呈规则的结晶状排列,用~(125)I标记,以免疫沉淀与SDS—PAGE相结合的方法分析HAV病毒衣壳蛋白,并分离出能与抗HAV抗体起反应的Vp1、Vp2及Vp3。  相似文献   
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