为了认识痕量元素As在飞灰中的富集特性,利用密度泛函理论研究了砷的典型氧化物AsO在飞灰中的主要成分SiO_2模型上的吸附机理,对优化后的吸附构型进行能量计算、AIM理论、Mulliken电荷分析以及定域化轨道指示函数(LOL)填色图分析,剖析了...为了认识痕量元素As在飞灰中的富集特性,利用密度泛函理论研究了砷的典型氧化物AsO在飞灰中的主要成分SiO_2模型上的吸附机理,对优化后的吸附构型进行能量计算、AIM理论、Mulliken电荷分析以及定域化轨道指示函数(LOL)填色图分析,剖析了AsO与SiO_2表面的相互作用。结果表明,AsO在无定型SiO_2表面的缺陷位的吸附能均大于50 k J/mol,吸附构型均为典型的化学吸附。在无定型SiO_2缺陷活性位点形成的As-Si键、Si-O键和As-O键强度较大,均属于共价键;SiO_2与AsO之间为共价相互作用。展开更多
用非限制性密度泛函方法UBP86泛函结合def2-TZVP基组获得了Ni2～6团簇的几何结构并用ELF(ElectronLocalized Function)和LOL(Localized Orbital Locator)函数对小镍团簇的电子结构进行拓扑分析.研究结果表明,除Ni2团簇外,团簇中Ni—Ni...用非限制性密度泛函方法UBP86泛函结合def2-TZVP基组获得了Ni2～6团簇的几何结构并用ELF(ElectronLocalized Function)和LOL(Localized Orbital Locator)函数对小镍团簇的电子结构进行拓扑分析.研究结果表明,除Ni2团簇外,团簇中Ni—Ni键的成键临界点不在键轴上,为弯曲键.镍团簇中Ni—Ni间的金属键为部分共价键,其价层Basin的布局数均小于1e,并且团簇中存在多个多中心价层Basin.团簇中各个化学键均强烈离域化.团簇中的单电子主要位于内层轨道,并没有参与成键.展开更多
AIM:To propose a surgical technique that successfully reopened the empty and intact capsular bag after long periods of closure,with repositioning of the intraocular lens(IOL)from the ciliary sulcus into its preferred ...AIM:To propose a surgical technique that successfully reopened the empty and intact capsular bag after long periods of closure,with repositioning of the intraocular lens(IOL)from the ciliary sulcus into its preferred habitat inside the capsular bag.METHODS:This is a case series,prospective,and interventional study.The technique was first performed on an aphakic high myope with a closed posterior capsule for 18 y.Afterwards,five patients with recurrently displaced sulcus IOLs for a range of 1 mo to 7 y were performed for the same technique.During surgery,identifying a"telltale white line"was an important landmark for detecting the site of major adhesions between the edge of the capsulorhexis and the posterior capsule.These adhesions were freed using combined manual and viscoelastic dissection,followed by an easier freeing of adhesions along the whole capsular bag.The IOL was safely implanted,exchanged,or introduced from the sulcus into the fibrotic and closed capsular bag.Patients were followed up for a period ranging from 6 to 17 mo postoperatively.RESULTS:All the patients experienced a remarkable improvement in their subjective refraction.Slit lamp examination showed a postoperative centralized IOL in the bag.The follow up visits confirmed visual and IOL stability.CONCLUSION:This newly-introduced surgical technique facilitates the reopening of the empty yet intact capsular bag that has been closed by fibrotic proliferations,with secured implantation of the IOL inside the capsular bag.Patients with inadvertent implantation of IOLs into the ciliary sulcus,yet having an intact capsular bag,can benefit from this technique.展开更多
细菌脂蛋白是一种脂质修饰的膜蛋白,参与细胞膜合成等多种重要生理过程。脂蛋白形成过程依赖于Lol转运系统,该蛋白最先在细胞质中以前体的形式合成,然后在细胞膜上被加工为成熟脂蛋白,锚定于细菌外膜周质侧。Lol系统由LolA-E五种蛋白组...细菌脂蛋白是一种脂质修饰的膜蛋白,参与细胞膜合成等多种重要生理过程。脂蛋白形成过程依赖于Lol转运系统,该蛋白最先在细胞质中以前体的形式合成,然后在细胞膜上被加工为成熟脂蛋白,锚定于细菌外膜周质侧。Lol系统由LolA-E五种蛋白组成,其中脂蛋白在周质空间中依赖伴侣蛋白LolA进行转运,LolA将脂蛋白以"mouth to mouth"的方式从LolCDE转运至LolB,进而完成脂蛋白定位。重点对周质分子伴侣LolA结构、参与的转运体系及其生物学功能进行综述,旨在通过对脂蛋白转运分子机制的理解为感染性疾病的治疗提供更多的药物靶点。展开更多
It is unpractical to learn the optimal structure of a big Bayesian network(BN)by exhausting the feasible structures,since the number of feasible structures is super exponential on the number of nodes.This paper propos...It is unpractical to learn the optimal structure of a big Bayesian network(BN)by exhausting the feasible structures,since the number of feasible structures is super exponential on the number of nodes.This paper proposes an approach to layer nodes of a BN by using the conditional independence testing.The parents of a node layer only belong to the layer,or layers who have priority over the layer.When a set of nodes has been layered,the number of feasible structures over the nodes can be remarkably reduced,which makes it possible to learn optimal BN structures for bigger sizes of nodes by accurate algorithms.Integrating the dynamic programming(DP)algorithm with the layering approach,we propose a hybrid algorithm—layered optimal learning(LOL)to learn BN structures.Benefitted by the layering approach,the complexity of the DP algorithm reduces to O(ρ2^n?1)from O(n2^n?1),whereρ<n.Meanwhile,the memory requirements for storing intermediate results are limited to O(C k#/k#^2 )from O(Cn/n^2 ),where k#<n.A case study on learning a standard BN with 50 nodes is conducted.The results demonstrate the superiority of the LOL algorithm,with respect to the Bayesian information criterion(BIC)score criterion,over the hill-climbing,max-min hill-climbing,PC,and three-phrase dependency analysis algorithms.展开更多
文摘为了认识痕量元素As在飞灰中的富集特性,利用密度泛函理论研究了砷的典型氧化物AsO在飞灰中的主要成分SiO_2模型上的吸附机理,对优化后的吸附构型进行能量计算、AIM理论、Mulliken电荷分析以及定域化轨道指示函数(LOL)填色图分析,剖析了AsO与SiO_2表面的相互作用。结果表明,AsO在无定型SiO_2表面的缺陷位的吸附能均大于50 k J/mol,吸附构型均为典型的化学吸附。在无定型SiO_2缺陷活性位点形成的As-Si键、Si-O键和As-O键强度较大,均属于共价键;SiO_2与AsO之间为共价相互作用。
文摘用非限制性密度泛函方法UBP86泛函结合def2-TZVP基组获得了Ni2～6团簇的几何结构并用ELF(ElectronLocalized Function)和LOL(Localized Orbital Locator)函数对小镍团簇的电子结构进行拓扑分析.研究结果表明,除Ni2团簇外,团簇中Ni—Ni键的成键临界点不在键轴上,为弯曲键.镍团簇中Ni—Ni间的金属键为部分共价键,其价层Basin的布局数均小于1e,并且团簇中存在多个多中心价层Basin.团簇中各个化学键均强烈离域化.团簇中的单电子主要位于内层轨道,并没有参与成键.
文摘AIM:To propose a surgical technique that successfully reopened the empty and intact capsular bag after long periods of closure,with repositioning of the intraocular lens(IOL)from the ciliary sulcus into its preferred habitat inside the capsular bag.METHODS:This is a case series,prospective,and interventional study.The technique was first performed on an aphakic high myope with a closed posterior capsule for 18 y.Afterwards,five patients with recurrently displaced sulcus IOLs for a range of 1 mo to 7 y were performed for the same technique.During surgery,identifying a"telltale white line"was an important landmark for detecting the site of major adhesions between the edge of the capsulorhexis and the posterior capsule.These adhesions were freed using combined manual and viscoelastic dissection,followed by an easier freeing of adhesions along the whole capsular bag.The IOL was safely implanted,exchanged,or introduced from the sulcus into the fibrotic and closed capsular bag.Patients were followed up for a period ranging from 6 to 17 mo postoperatively.RESULTS:All the patients experienced a remarkable improvement in their subjective refraction.Slit lamp examination showed a postoperative centralized IOL in the bag.The follow up visits confirmed visual and IOL stability.CONCLUSION:This newly-introduced surgical technique facilitates the reopening of the empty yet intact capsular bag that has been closed by fibrotic proliferations,with secured implantation of the IOL inside the capsular bag.Patients with inadvertent implantation of IOLs into the ciliary sulcus,yet having an intact capsular bag,can benefit from this technique.
文摘细菌脂蛋白是一种脂质修饰的膜蛋白,参与细胞膜合成等多种重要生理过程。脂蛋白形成过程依赖于Lol转运系统,该蛋白最先在细胞质中以前体的形式合成,然后在细胞膜上被加工为成熟脂蛋白,锚定于细菌外膜周质侧。Lol系统由LolA-E五种蛋白组成,其中脂蛋白在周质空间中依赖伴侣蛋白LolA进行转运,LolA将脂蛋白以"mouth to mouth"的方式从LolCDE转运至LolB,进而完成脂蛋白定位。重点对周质分子伴侣LolA结构、参与的转运体系及其生物学功能进行综述,旨在通过对脂蛋白转运分子机制的理解为感染性疾病的治疗提供更多的药物靶点。
基金supported by the National Natural Science Foundation of China(61573285)
文摘It is unpractical to learn the optimal structure of a big Bayesian network(BN)by exhausting the feasible structures,since the number of feasible structures is super exponential on the number of nodes.This paper proposes an approach to layer nodes of a BN by using the conditional independence testing.The parents of a node layer only belong to the layer,or layers who have priority over the layer.When a set of nodes has been layered,the number of feasible structures over the nodes can be remarkably reduced,which makes it possible to learn optimal BN structures for bigger sizes of nodes by accurate algorithms.Integrating the dynamic programming(DP)algorithm with the layering approach,we propose a hybrid algorithm—layered optimal learning(LOL)to learn BN structures.Benefitted by the layering approach,the complexity of the DP algorithm reduces to O(ρ2^n?1)from O(n2^n?1),whereρ<n.Meanwhile,the memory requirements for storing intermediate results are limited to O(C k#/k#^2 )from O(Cn/n^2 ),where k#<n.A case study on learning a standard BN with 50 nodes is conducted.The results demonstrate the superiority of the LOL algorithm,with respect to the Bayesian information criterion(BIC)score criterion,over the hill-climbing,max-min hill-climbing,PC,and three-phrase dependency analysis algorithms.
