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1.
杨亲二   《广西植物》1995,15(4):354-357
本文对鸭跖草科的穿鞘花Amischotolypehispida(LessetA.Rich.)Hong进行了核形态研究。其静止核和有丝分裂前期染色体分别属于复杂中央染色微粒型和中间型;染色体数目为2n=36,核型公式为2n=4m+28sm+4st。本种的核型为首次报道。  相似文献   
2.
Based on detailed study of available specimens and perusal of literature, it is shown that Melanoseris lessertiana or Mulgedium lessertianum is not present in China and corresponding reports in the floristic literature of China actually refer to a species originally described as Mulgedium qinghaicum, and correctly placed as Melanoseris qinghaica, a species here reported for the first time also for Bhutan. Mqinghaica can be clearly distinguished from Mlessertiana by achene shape and anther tube length. The rare and little known Yunnan endemic, originally described as Lactuca monocephala and tentatively considered as conspecific with Mlessertiana recently, is confirmed as an independent species related to the Matropurpurea complex. Of two recently described species from N Pakistan and Kashmir morphologically allied to Mlessertiana, Cicerbita alii is confirmed as a separate species and transferred to Melanoseris, while Castorensis is considered as conspecifc with Mlessertiana.  相似文献   
3.
The functional domain composition is introduced to predict the structural class of a protein or domain according to the following classification: all-alpha, all-beta, alpha/beta, alpha+beta, micro (multi-domain), sigma (small protein), and rho (peptide). The advantage by doing so is that both the sequence-order-related features and the function-related features are naturally incorporated in the predictor. As a demonstration, the jackknife cross-validation test was performed on a dataset that consists of proteins and domains with only less than 20% sequence identity to each other in order to get rid of any homologous bias. The overall success rate thus obtained was 98%. In contrast to this, the corresponding rates obtained by the simple geometry approaches based on the amino acid composition were only 36-39%. This indicates that using the functional domain composition to represent the sample of a protein for statistical prediction is very promising, and that the functional type of a domain is closely correlated with its structural class.  相似文献   
4.
Genitourinary cancers comprise of a heterogenous group of cancers of which renal cell carcinoma, urothelial bladder carcinoma, and prostate adenocarcinoma are the most commonly encountered subtypes. A lot of research is ongoing using various strategies for exploration of novel biomarkers for genitourinary cancers. These biomarkers would not reduce the need for invasive diagnostic techniques but also could be used for early and accurate diagnosis to improve the clinical management required for the disease. Moreover, selecting the appropriate treatment regimen for the responsive patients based on these biomarkers would reduce the treatment toxicity as well as cost. Biomarkers identified using various advanced techniques like next generation sequencing and proteomics, which have been classified as immunological biomarkers, tissue-specific biomarkers and liquid biomarkers. Immunological biomarkers include markers of immunological pathways such as CTLA4, PD-1/PDl-1, tissue biomarkers include tissue specific molecules such as PSA antigen and liquid biomarkers include biomarkers detectable in urine, circulating cells etc.The purpose of this review is to provide a brief introduction to the most prevalent genitourinary malignancies, including bladder, kidney, and prostate cancers along with a major focus on the novel diagnostic biomarkers and the importance of targeting them prior to genitourinary cancers treatment. Understanding these biomarkers and their potential in diagnosis of genitourinary cancer would not help in early and accurate diagnosis as mentioned above but may also lead towards a personalized approach for better diagnosis, prognosis and specified treatment approach for an individual.  相似文献   
5.
应用光镜和扫描电镜对山东菊科莴苣亚族11属18种、1变种植物的花粉形态进行了观察研究。结果表明:莴苣亚族植物的花粉呈球形,具3~4沟孔,花粉表面具有网状纹饰,粗网眼15~21个,网脊上具1行刺,属于蒲公英(Taraxacum)型,与已报道的莴苣亚族其它属种的花粉形态相一致。通过莴苣亚族属间花粉形态的比较,认为花粉形态在属间分类上意义不大。  相似文献   
6.
A behavior-analytic model of transitive inference (TI) as relational reasoning with derived comparative relations is outlined. Following nonarbitrary relational training and testing to establish contextual functions of “more than” (>) and “less than” (<) for two abstract stimuli, two groups of participants learned a series of contextually controlled more than or less than relations (All-More: E > D > C > B > A; All-Less: A < B < C < D < E). On meeting the training criterion, inferential tests were presented to both groups involving mutually entailed relations (All-More: A < B, B < C, C < D and D < E; All-Less: B > A, C > B, D > C and E > D) and one-step (A < C, B < D, C < E, C > A, D > B and E > C) and two-step (A < D, B < E, D > A and E > B) combinatorially entailed relations. Performance accuracy on the trained and inferential tasks was uniformly high across both groups, with no significant differences observed. In both groups, however, performance accuracy differed significantly on one-step and two-step combinatorially entailed tasks involving the same or different relation to that trained. The present findings demonstrate complex relational reasoning with derived comparative relations, replicate several key effects from the literature on TI and have potential implications for the development of a contemporary behavior-analytic account of TI.  相似文献   
7.
统计了1998~2011年的14年间,国家自然科学基金委员会农学基础和作物学学科对地区科学基金的资助情况,分析了国家自然科学基金地区科学基金项目对地区农业科研人才的培养以及在农业科技进步中发挥的作用。  相似文献   
8.
摘要 目的:对比插管-肺表面活性物质给药-拔管(INSURE)技术与微创肺表面活性物质给药(LISA)技术对极早产儿呼吸窘迫综合征患者的疗效。方法:选取2018年1月至2020年4月我院收治的108例极早产儿呼吸窘迫综合征患者作为研究对象,随机将其分为两组,对照组54例,给予INSURE技术治疗,研究组54例,给予LISA技术治疗。观察两组患儿治疗前后的血浆β-内啡肽(β-EP)、智力发展指数(MDI)、精神运动发育指数(PDI)水平,对比两组治疗过程中的指标、并发症、神经运动评价(纠正胎龄6月龄和12月龄的Gesell婴幼儿发育检查量表检测发育商DQ)及死亡率。结果:(1)两组患儿治疗后β-EP水平均下降,MDI、PD水均提高,研究组?茁-EP水平明显低于对照组,MDI、PD水平高于对照组(P<0.05)。(2)研究组患者反复呼吸暂停发生率明显优于对照组(P<0.05);两组对比,心动过缓、血氧饱和度(SpO2)降低、72 h内机械通气、再次使用肺泡表面活性物质(PS)等指标对比无差异(P>0.05);(3)两组患儿住院期间气胸、视网膜病变、脑室内出血(Ⅲ°或以上)、支气管肺发育不良等不良并发症和死亡率对比无差异(P>0.05)。(4)两组患儿在纠正胎龄6月龄和12月龄的5个能区评分和总发育商(DQ)比较无差异(P>0.05)。结论:LISA技术可减轻呼吸窘迫综合征极早产儿的神经发育损伤,亦能减少住院期间相关早产儿并发症,且对婴儿远期神经心理发育无不良影响,具有很好的临床价值,值得临床推广和应用。  相似文献   
9.
Given the sequence of a protein, how can we predict whether it is a membrane protein or non-membrane protein? If it is, what membrane protein type it belongs to? Since these questions are closely relevant to the function of an uncharacterized protein, their importance is self-evident. Particularly, with the explosion of protein sequences entering into databanks and the relatively much slower progress in using biochemical experiments to determine their functions, it is highly desired to develop an automated method that can be used to give a fast answers to these questions. By hybridizing the functional domain (FunD) and pseudo-amino acid composition (PseAA), a new strategy called FunD-PseAA predictor was introduced. To test the power of the predictor, a highly non-homologous data set was constructed where none of proteins has 25% sequence identity to any other. The overall success rates obtained with the FunD-PseAA predictor on such a data set by the jackknife cross-validation test was 85% for the case in identifying membrane protein and non-membrane protein, and 91% in identifying the membrane protein type among the following 5 categories: (1) type-1 membrane protein, (2) type-2 membrane protein, (3) multipass transmembrane protein, (4) lipid chain-anchored membrane protein, and (5) GPI-anchored membrane protein. These rates are much higher than those obtained by the other methods on the same stringent data set, indicating that the FunD-PseAA predictor may become a useful high throughput tool in bioinformatics and proteomics.  相似文献   
10.
The possible existence of less common hydrogen bonds in three lariat ethers and their alkali-metal ionic complexes have been investigated with one- and two-dimensional (1D and 2D) proton and carbon-13 high resolution liquid state NMR spectroscopy. The occurrence of hydrogen-bonding induced by the addition of metal ions has been identified with the observation of indirect dipolar coupling between the coupling partners involved in the hydrogen-bonding. The addition of metal ions, moreover, causes appreciable change of chemical shift of several protons and carbons. The chemical shift change depends on the ion radius, larger ions causing smaller change. Moreover, the change of chemical shift is in coincidence with the occurrence of hydrogen-bonding. The values of the coupling constants have been obtained for each of these hydrogen bonds and were used for evaluating the hydrogen-bond strength. An intriguing and surprising observation is that a C-H***O hydrogen bond identified in solution by this work was not found in the previous study with X-ray diffraction or other methods.  相似文献   
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