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1.
确定药物副作用发生频率是药物风险-效益评估的关键问题.随机对照临床试验方法性能有限且成本昂贵.随着药物临床试验数据的增加,基于数据驱动计算方法研究药物-副作用关系成为可能.文章提出一种基于药物-副作用协同传播模型的药物副作用发生频率预测方法.该方法基于已知的药物副作用发生频率信息构建相似网络,基于已知频率信息在网络中高阶协同传播过程预测药物副作用发生频率.此外,提出一种基于邻域学习的相似网络构建方法,进一步提升模型预测性能.在SIDER 4.1和ADReCS 3.1中获得的真实的药物-副作用频率数据集上进行实验,相较于现有最优方法,提出的方法在均方根误差和平均绝对误差指标上分别下降了6.98%、7.23%.  相似文献   

2.
目的:分析小分子药物的优势,提出小分子库是良好的药物筛选库。方法:首先从DrugBank中筛选单靶点小分子药物,构建靶点—结构网络,然后探索小分子药物的化学空间,最后对主要化学性质进行统计分析。结果:小分子药物靶点在结构分类上α/β类型最多(47.98%),并且最古老的fold覆盖了较多的药物和靶点;另外,小分子药物有着良好的分布多样性,而且化学性质也有较好的优势。结论:单靶点结构网络的构建为进一步对天然产物的演变研究提供了新思路,小分子库是药物筛选良好的化合物库。  相似文献   

3.
提出了一种基于异构图神经网络(HGNN)的药物重定位方法。该方法对药物-疾病关联网络、药物-药物相似性网络和疾病-疾病相似性网络的信息进行并行融合,有效地保留了各个网络的信息。此外,针对图卷积神经网络(GCN)提取信息能力的不足,本工作加入了图注意力网络(GAT)和层注意力机制,增强了特征提取能力,进一步提高了模型的预测性能。实验验证表明,提出的网络在Fdataset上达到了94.4%的AUROC和57.0%的AUPRC,在Cdataset上达到了95.9%的AUROC和65.3%的AUPR,超过了现有的基准方法。  相似文献   

4.
基于回归模型的网络排序算法预测药物靶点关系   总被引:1,自引:1,他引:0  
计算方法预测新的药物靶点关系是新药研发的主要途径,基于相似药物较容易与相似靶蛋白绑定的假定和标签传播的框架,提出一种基于脊回归模型的网络排序计算方法挖掘潜在的药物靶点作用关系;并对四个数据集分别进行30次10—CV预测分析。结果表明,与现有网络算法DBSI、TBSI和NBI相比,该预测算法能得到较高的ROC曲线面积,具有较好的应用前景。  相似文献   

5.
精神分裂症是常见的精神障碍类疾病.目前,治疗精神分裂症的药物存在疗效差、副作用大和耐药性的问题,迫切需要开发新的药物,而发现新的药物靶基因是开发新药的重要环节.为了预测精神分裂症药物的靶基因,我们首先基于DrugBank中药物已知的靶基因,使用网络算法GenePANDA预测出候选靶基因;之后,我们对药物已知靶基因进行功能富集分析,使用富集出的生物学通路筛选候选靶基因,最终得到48个候选靶基因.其中,29个基因被报道和精神分裂症直接相关,13个基因被报道为精神分裂症药物的靶基因.此外,在DrugBank中共有54种药物靶向预测出的基因,其中17种药物被研究报道可用于治疗精神分裂症.  相似文献   

6.
陶勇  梁颖  杨晓平 《科技资讯》2010,(8):237-238
目的:探讨抗菌药物滴注速度对药物产生不良反应的影响。方法:采用统计学的方法,查阅我院抗菌药物的药品说明书以及各类药学专业文献,进行总结、分析与评价。结果:我院抗菌药物说明书中有关滴注速度要求的药物有13种,占所查说明书的48%;各种药学文献中有明确抗菌药物滴注速度的29种,约占所检药物品种的41%。结语:滴注速度不当是抗菌药物出现不良反应的一个重要因素。忽视滴注速度的合理选择,抗菌药物不能达到理想的治疗效果,而且还可能出现严重的不良反应。  相似文献   

7.
提出一种融合元路径信息的图神经网络模型, 用于预测药物-靶标相互作用(GMDTI)。首先根据8个数据集中的药物、靶标、疾病和副作用数据以及它们之间的8种作用关系, 构建药物-靶标异质信息网络(HIN); 然后定义两条元路径来捕获药物-靶标HIN 中的不同子结构信息和不同节点间隐藏的语义信息, 并应用图神经网络的方法聚合节点的一阶邻居信息和元路径中节点间的语义信息; 最后利用端到端的学习方法完成DTIs预测。该方法同时考虑药物-靶标HIN的结构特性和元路径语义信息, 有助于学习到更多潜在的药物-靶标作用关系。实验结果表明, GMDTI的预测准确率高于所有基线模型, AUC达到98.6%, AUPR达到94.5%。同时通过调整数据的稀疏度和降噪实验, 证明GMDTI具备优于所有基线模型的鲁棒性。  相似文献   

8.
数据发掘和定量的构效关系(QSAR)是药物发现中重要的研究方法.本首先介绍了一种极具实用价值的无模式分类与模式识别的基本方法,即k最近邻法.该法应用于QSAR研究时通过若干电子、拓扑结构参数计算分子间的欧氏距离来比较其相似性,并以最相似若干分子已知活性的加权平均来估算新结构的活性数据.整个运算过程利用模拟退火法并结合遗传算法和留一-交叉验证法优选出适当的结构参数和近邻数目.本以一组已知活性的单核苷酸分子为例,对NCI和Maybridge化学数据库的分子运用kNN法进行数据发掘,通过计算数据库中分子与已知活性分子的相似性来进行筛选和活性预测,从而得到与已知结构最相似的分子,为搜寻潜在前导化合物提供重要参考信息.  相似文献   

9.
针对药物靶点预测中类别不平衡的问题,归纳总结相关学者提出的各种处理方法,力求改善药物靶点预测中类别不平衡状况,为药物靶点预测的相关研究提供有利的参考和借鉴。以中国知网、维普、万方数据和PubMed作为主要文献检索平台,查询整理相关文献,对药物靶点预测中类别不平衡问题的研究进行综述。共检索到相关有效文献81篇,结果显示类别不平衡问题主要从数据层面、学习算法层面和构造负样本层面着手处理。其中,数据层面的方法主要通过减少或增加一定的数据来平衡数据集;学习算法层面的方法主要利用半监督学习和集成学习思想来使分类算法适用于不平衡数据或构造出平衡数据集;构造负样本层面的方法则是采用一些策略从大量未标记样本中筛选出高可靠的负样本。药物靶点预测中类别不平衡问题的处理方法较多,不同的方法均有特色,但各方法之间无明显差异,都可一定程度上提高药物靶点预测水平,从而为药物靶点预测相关研究提供有力的技术支持。  相似文献   

10.
识别药物-靶蛋白作用关系是当前药物研究的重要内容,其可帮助识别已有药物的新功能,发现药物的"偏靶蛋白"等。现有预测算法对新药物的作用靶蛋白,及新靶蛋白的作用药物预测存在困难,由此提出一种新奇的基于流形正则化非负矩阵分解的新药物/新靶蛋白作用关系预测算法,该方法首先通过聚类算法构建新药物/新靶蛋白的初始作用标签,然后设计引入流形学习正则化约束的非负矩阵分解算法预测药物-靶蛋白作用关系,最后在四个经典数据集中测试,并与最新预测算法BLM-NII、RLS-WNN和WKNKN+WGRMF算法进行比较,证明本文算法可获取较高的预测精度。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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