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991.
用两系法杂交稻组合培矮 64s/E32、培矮 64s/9311、粤杂122和常规水稻品种粤香占、特三矮 2号为材料,1998年早季在广州研究了它们的透光率和对低光强适应性的差异后认为:1.生育期不同其直射光透光率的变化是分蘖期>始穗期<收割期,即透光率由大→小→大变化,它与叶片开张角随生育期变化的情况相对应,但与叶面积指数由小→大→小的变化相反。2.不同类型早籼稻在始穗后遮光处理降低透光率,生育期短的粤杂122、粤香占对低光强的适应性比其余组合或品种好,其单穗重降幅小。  相似文献   
992.
三倍体芒草自然杂交后代数量性状遗传多样性研究   总被引:1,自引:0,他引:1  
以三倍体芒草奇岗的自然杂交后代为研究对象,对后代群体的16个数量性状分别进行变异分析、主成分分析和聚类分析。研究结果表明:(1)该杂交群体的变异系数在14.41%~151.85%之间,平均变异系数为51.22%,说明杂交后代变异广泛。(2)主成分分析结果表明,前4个主成分反映原变量的80.206%的信息。第1主成分贡献率为48.74%,较大载荷性状有分蘖数、丛径、基部周长、单株鲜重和单株干重;第2主成分贡献率为16.313%,较大载荷性状有外径、内径、单茎干重、单茎鲜重和含水量;第3主成分贡献率为7.775%,仅有腋芽数一个较大载荷性状;第4主成分贡献率为7.378%,仅叶片数一个较大载荷。(3)聚类分析结果表明,将66份奇岗自然杂交后代和6份母本奇岗种质分为4大类。第Ⅰ类材料因本身各性状不足,产量很低,不适合筛选高产种质;第Ⅱ类材料各性状变异系数普遍较小,性状稳定,适合作为育种的备选类群;第Ⅲ类材料因枯黄较少,更适合做发酵类能源草或青贮牧草;第Ⅳ类材料生物产量因子及其产量构成因子都明显优于母本,是较好的育种材料。以上研究结果对筛选芒属植物优良种质、创新芒属植物种质资源有积极意义,并为芒属植物多倍体育种提供理论依据和材料基础。  相似文献   
993.
Journal of Industrial Microbiology & Biotechnology - To make the process of producing sophorolipids by Candida bombicola truly sustainable, we investigated production of these biosurfactants on...  相似文献   
994.
Biomechanics and Modeling in Mechanobiology - Computational models have been used to calculate plaque stress and strain for plaque progression and rupture investigations. An intravascular...  相似文献   
995.

The co-culture system of denitrifying anaerobic methane oxidation (DAMO) and anaerobic ammonium oxidation (Anammox) has a potential application in wastewater treatment plant. This study explored the effects of permutation and combination of nitrate, nitrite, and ammonium on the culture enrichment from freshwater sediments. The co-existence of NO3 , NO2 , and NH4 + shortened the enrichment time from 75 to 30 days and achieved a total nitrogen removal rate of 106.5 mg/L/day on day 132. Even though ammonium addition led to Anammox bacteria increase and a higher nitrogen removal rate, DAMO bacteria still dominated in different reactors with the highest proportion of 64.7% and the maximum abundance was 3.07 ± 0.25 × 108 copies/L (increased by five orders of magnitude) in the nitrite reactor. DAMO bacteria showed greater diversity in the nitrate reactor, and one was similar to M. oxyfera; DAMO bacteria in the nitrite reactor were relatively unified and similar to M. sinica. Interestingly, no DAMO archaea were found in the nitrate reactor. This study will improve the understanding of the impact of nitrogen source on DAMO and Anammox co-culture enrichment.

  相似文献   
996.
哈维氏弧菌(Vibrio harveyi)是水产动物的常见致病菌,对人类健康和水产经济带来巨大威胁。抗生素的滥用使得药物残留和耐药性问题变得日益严重。因此,迫切需要寻找新型、不易产生耐药性和低毒的抗菌物质。本文研究黄芩醇提物对哈维氏弧菌的抑制作用及抑菌机制。实验结果表明,黄芩醇提物对哈维氏弧菌的抑菌圈为18.33±0.58 mm,最低抑菌浓度(MIC)和最小杀菌浓度(MBC)分别为7.92 mg/mL和15.84 mg/mL。经分析型扫描电镜(SEM)观察和细菌胞内外蛋白质浓度测定,发现实验组菌体表面虽有细小破裂,但形态依然完整,表面光滑,菌体细胞膜仍保持相对完整性;通过SDS-PAGE、蛋白质质谱(MALDI-TOF-TOF MS)和实时荧光定量PCR分析,显示黄芩醇提物抑制哈维氏弧菌体内NAD特异性的谷氨酸脱氢酶(NAD-specific glutamate dehydrogenase, NAD-GDH)及其mRNA的表达。本研究表明,黄芩醇提物通过下调NAD特异性的谷氨酸脱氢酶表达而抑制哈维氏弧菌的生长,为中药应用于水产养殖提供了新的证据。  相似文献   
997.
马铃薯块茎切片- 软腐病菌亲和互作过程中, 不同强度的亲和互作中活性氧的释放有其不同的特点。在强亲和互作中的24 小时内,无明显的活性氧释放。但在弱亲和互作中,互作8 小时后,即有明显的活性氧的释放,20 小时达到高峰,并且这种活性氧的释放提高寄主的抗病性。试验显示马铃薯块茎切片与软腐病菌的亲和互作诱导寄主抗氰交替途径的运行,SHAM 处理降低亲和互作过程中寄主的感病性, 同时SHAM 处理也促进亲和互作中寄主活性氧释放高峰的出现, 表明抗氰交替途径的运行可通过抑制亲和互作中寄主活性氧的产生而促进寄主的感病性。从而证明了一种新的寄主植物抗感病反应机制  相似文献   
998.

Background

Similar diseases are always caused by similar molecular origins, such as diasease-related protein-coding genes (PCGs). And the molecular associations reflect their similarity. Therefore, current methods for calculating disease similarity often utilized functional interactions of PCGs. Besides, the existing methods have neglected a fact that genes could also be associated in the gene functional network (GFN) based on intermediate nodes.

Methods

Here we presented a novel method, InfDisSim, to deduce the similarity of diseases. InfDisSim utilized the whole network based on random walk with damping to model the information flow. A benchmark set of similar disease pairs was employed to evaluate the performance of InfDisSim.

Results

The region beneath the receiver operating characteristic curve (AUC) was calculated to assess the performance. As a result, InfDisSim reaches a high AUC (0.9786) which indicates a very good performance. Furthermore, after calculating the disease similarity by the InfDisSim, we reconfirmed that similar diseases tend to have common therapeutic drugs (Pearson correlation γ2?=?0.1315, p?=?2.2e-16). Finally, the disease similarity computed by infDisSim was employed to construct a miRNA similarity network (MSN) and lncRNA similarity network (LSN), which were further exploited to predict potential associations of lncRNA-disease pairs and miRNA-disease pairs, respectively. High AUC (0.9893, 0.9007) based on leave-one-out cross validation shows that the LSN and MSN is very appropriate for predicting novel disease-related lncRNAs and miRNAs, respectively.

Conclusions

The high AUC based on benchmark data indicates the method performs well. The method is valuable in the prediction of disease-related lncRNAs and miRNAs.
  相似文献   
999.

Background

Guideline implementation tools (GI tools) can improve clinician behavior and patient outcomes. Analyses of guidelines published before 2010 found that many did not offer GI tools. Since 2010 standards, frameworks and instructions for GI tools have emerged. This study analyzed the number and types of GI tools offered by guidelines published in 2010 or later.

Methods

Content analysis and a published GI tool framework were used to categorize GI tools by condition, country, and type of organization. English-language guidelines on arthritis, asthma, colorectal cancer, depression, diabetes, heart failure, and stroke management were identified in the National Guideline Clearinghouse. Screening and data extraction were in triplicate. Findings were reported with summary statistics.

Results

Eighty-five (67.5%) of 126 eligible guidelines published between 2010 and 2017 offered one or more of a total of 464 GI tools. The mean number of GI tools per guideline was 5.5 (median 4.0, range 1 to 28) and increased over time. The majority of GI tools were for clinicians (239, 51.5%), few were for patients (113, 24.4%), and fewer still were to support implementation (66, 14.3%) or evaluation (46, 9.9%). Most clinician GI tools were guideline summaries (116, 48.5%), and most patient GI tools were condition-specific information (92, 81.4%). Government agencies (patient 23.5%, clinician 28.9%, implementation 24.1%, evaluation 23.5%) and developers in the UK (patient 18.5%, clinician 25.2%, implementation 27.2%, evaluation 29.1%) were more likely to generate guidelines that offered all four types of GI tools. Professional societies were more likely to generate guidelines that included clinician GI tools.

Conclusions

Many guidelines do not include any GI tools, or a variety of GI tools for different stakeholders that may be more likely to prompt guideline uptake (point-of-care forms or checklists for clinicians, decision-making or self-management tools for patients, implementation and evaluation tools for managers and policy-makers). While this may vary by country and type of organization, and suggests that developers could improve the range of GI tools they develop, further research is needed to identify determinants and potential solutions. Research is also needed to examine the cost-effectiveness of various types of GI tools so that developers know where to direct their efforts and scarce resources.
  相似文献   
1000.
Selection due to cuckoo parasitism is responsible for the evolution of anti-parasitism defenses in hosts. Different host species breeding sympatrically with a single parasitic cuckoo may evolve different strategies to reduce the risk of counter cuckoo parasitism, resulting in different interactions between cuckoos and hosts in areas of sympatry. Here, we studied the coevolutionary interactions between Himalayan cuckoos Cuculus saturatus and 2 sympatric and closely related potential hosts belonging to the family Pycnonotidae, the brown-breasted bulbul Pycnonotus xanthorrhous and the collared finchbill Spizixos semitorques. We investigated parasitism rates and nest-site selection (nest height, nest cover, human disturbance, perch height, forest distance, and degree of concealment) related to parasitism risk, nest defense against a cuckoo dummy, and egg rejection against cuckoo model eggs. Bulbuls used specific nest sites that were further away from forests than those of finchbills, and they behaved more aggressively toward cuckoos than finchbills. In contrast, bulbuls possessed moderate egg rejection ability, whereas the finchbill rejected 100% of cuckoo model eggs. We suggest that selection of a nest site away from forests by the bulbul explains the absence of parasitism by Himalayan cuckoos. We suggest that these interspecific differences in nest-site selection and nest defense indicate alternative responses to selection due to cuckoos.  相似文献   
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