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991.
何杜博  孙胜祥  梁新  谢力  张侃 《控制与决策》2024,39(7):2295-2304
针对多目标回归中的特征选择问题,提出一种基于自适应图学习的多目标特征选择算法,在单个框架中同时考虑3种关系结构:输入特征与目标输出、不同目标输出以及样本间的相关结构,并基于上述结构信息进行特征选择.首先,在传统稀疏回归模型中对系数矩阵施加低秩约束,利用低秩学习对特征间相关性以及目标间的依赖关系进行解耦学习;然后,构建基于样本局部结构信息的自适应图学习项,充分利用样本间的相似结构进行特征选择;进一步地,引入基于输出相关性的结构矩阵优化项,使模型能够更加充分地考虑目标间的相关性;最后,提出一种交替优化算法求解目标函数,并从理论上证明算法的收敛性.在公开数据集上的实验表明,所提方法相较于现有主流的多目标特征选择方法具有更好的性能和适用性.  相似文献   
992.
应用J2EE的制造过程资源管理信息系统研究   总被引:1,自引:1,他引:0  
通过对制造过程资源构成的分析,利用J2EE技术,开发浏览器/服务器三层网络体系结构的制造过程资源的管理信息系统.介绍该系统的体系结构,分析系统实现的关键技术.介绍系统的设备资源管理、工具库管理、物料资源管理、工艺资源管理、图文档管理和任务管理等子系统.  相似文献   
993.
探讨了自治系统级Internet平均路径长度的变化趋势问题。研究了理论模型及近5年的真实网络数据,发现两者中得到的Internet平均路径长度的变化趋势完全相反。分析了产生这种现象的原因,通过建模得到了计算真实情况下Internet平均路径长度的公式,在此基础上对2006年~2012年Internet的平均路径长度变化趋势进行了预测。  相似文献   
994.
995.
Juice, as a liquid foodstuff, is subject to spoilage and damage due to complications during transport and storage. The appearance of intact outer packaging often makes spoilage and damage difficult to detect. Therefore, it of particular importance to develop a fast, real-time material to evaluate liquid foodstuffs. In this paper, starch films with pH response characteristics are successfully prepared by inorganic ion modification by utilizing whole starch and amylopectin as raw materials. The mechanical properties, stability properties, hydrophilic properties and pH electrical signal response indices of the films are analyzed and measured. The films exhibit good electrical conductivity values with 1.0 mL of ion addition (10 mmol/L), causing the composite film to respond sensitively to solutions with varying pH values. In the test of spoiled orange juice, the full-component corn starch (CS) film has more sensitive resistance and current responses, which is more conducive for applications in the quality monitoring of juice. The results indicate that modified starch films can potentially be applied in the real-time monitoring of the safety of liquid foodstuffs.  相似文献   
996.
Mitochondrial i-AAA proteinase Yme1 is a multifunctional protein that plays important roles in maintaining mitochondrial protein homeostasis and regulating biogenesis and function of mitochondrial proteins. However, due to the complex interplay of mitochondria and the multifunctional nature of Yme1, how Yme1 affects mitochondrial function and protein homeostasis is still poorly understood. In this study, we investigated how YME1 deletion affects yeast Saccharomyces cerevisiae growth, chronological life span, mitochondrial protein homeostasis and function, with a focus on the mitochondrial oxidative phosphorylation (OXPHOS) complexes. Our results show that whilst the YME1 deleted cells grow poorly under respiratory conditions, they grow similar to wild-type yeast under fermentative conditions. However, the chronological life span is impaired, indicating that Yme1 plays a key role in longevity. Using highly enriched mitochondrial extract and proteomic analysis, we show that the abundances of many mitochondrial proteins are altered by YME1 deletion. Several components of the respiratory chain complexes II, III, IV and V were significantly decreased, suggesting that Yme1 plays an important role in maintaining the level and function of complexes II-V. This result was confirmed using blue native-PAGE and in-solution-based enzyme activity assays. Taken together, this study shows that Yme1 plays an important role in the chronological life span and mitochondrial protein homeostasis and has deciphered its function in maintaining the activity of mitochondrial OXPHOS complexes.  相似文献   
997.
Abnormal activation of the kynurenine and serotonin pathways of tryptophan metabolism is linked to a host of neuropsychiatric disorders. Concurrently, noninvasive brain stimulation (NIBS) techniques demonstrate high therapeutic efficacy across neuropsychiatric disorders, with indications for modulated neuroplasticity underlying such effects. We therefore conducted a scoping review with meta-analysis of eligible studies, conforming with the PRISMA statement, by searching the PubMed and Web of Science databases for clinical and preclinical studies that report the effects of NIBS on biomarkers of tryptophan metabolism. NIBS techniques reviewed were electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), and transcranial direct current stimulation (tDCS). Of the 564 search results, 65 studies were included with publications dating back to 1971 until 2022. The Robust Bayesian Meta-Analysis on clinical studies and qualitative analysis identified general null effects by NIBS on biomarkers of tryptophan metabolism, but moderate evidence for TMS effects on elevating serum serotonin levels. We cannot interpret this as evidence for or against the effects of NIBS on these biomarkers, as there exists several confounding methodological differences in this literature. Future controlled studies are needed to elucidate the effects of NIBS on biomarkers of tryptophan metabolism, an under-investigated question with substantial implications to clinical research and practice.  相似文献   
998.
Biotransformation of flavonoid dimer FD18 resulted in an active metabolite FM04. It was more druggable because of its improved physicochemical properties. FM04 (EC50 = 83 nM) was 1.8-fold more potent than FD18 in reversing P-glycoprotein (P-gp)-mediated paclitaxel (PTX) resistance in vitro. Similar to FD18, FM04 chemosensitized LCC6MDR cells towards multiple anticancer drugs by inhibiting the transport activity of P-gp and restoring intracellular drug levels. It stimulated the P-gp ATPase by 3.3-fold at 100 μM. Different from FD18, FM04 itself was not a transport substrate of P-gp and presumably, it cannot work as a competitive inhibitor. In the human melanoma MDA435/LCC6MDR xenograft, the co-administration of FM04 (28 mg/kg, I.P.) with PTX (12 mg/kg, I.V.) directly modulated P-gp-mediated PTX resistance and caused a 56% (*, p < 0.05) reduction in tumor volume without toxicity or animal death. When FM04 was administered orally at 45 mg/kg as a dual inhibitor of P-gp/CYP2C8 or 3A4 enzymes in the intestine, it increased the intestinal absorption of PTX from 0.2% to 14% in mice and caused about 57- to 66-fold improvement of AUC as compared to a single oral dose of PTX. Oral co-administration of FM04 (45 mg/kg) with PTX (40, 60 or 70 mg/kg) suppressed the human melanoma MDA435/LCC6 tumor growth with at least a 73% (***, p < 0.001) reduction in tumor volume without serious toxicity. Therefore, FM04 can be developed into a novel combination chemotherapy to treat cancer by directly targeting the P-gp overexpressed tumors or potentiating the oral bioavailability of P-gp substrate drugs.  相似文献   
999.
法门寺合十舍利塔,建筑高度147 m,呈双手合十造型,为竖向特别不规则结构.鉴于其结构体系及结构布置的复杂及体型超限,为确保该建筑结构的抗震安全性和适用性,本文利用SAP2000程序对该结构进行了动力特性和弹性时程分析.为了检验结构弹性时程分析的可靠性,将理论分析结果与其振动台试验结果进行了对比,并在此基础上,对该结构进行了抗震性能评价.  相似文献   
1000.
用密度泛函理论(DFT)中的B3LYP、B3PW91、B3P86方法研究硝酸正丙酯(n-propyl nitrate,NPN)和硝酸异丙醣(isopro- pyl nitrate,IPN)的平衡分子构型、前线轨道能(E_(HOMO)、E_(LUMO))、能差(△E=E_(LUMO)-E_(HOMO))和O-NO_2键的裂解能(BDE)。分析了两种硝酸酯分子和对应自由基的热稳定性。NPN和IPN中的O-NO_2键的裂解能用B3P86方法计算出最接近实验值。由O- NO_2键的裂解能符合文献中对应物质的表观活化能,推知两种物质的热分解反应只是单分子O-NO_2键的均裂反应。  相似文献   
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