scholarly journals A novel synthetic approach to hydroimidazo[1,5-b]pyridazines by the recyclization of itaconimides and HPLC–HRMS monitoring of the reaction pathway

2017 ◽  
Vol 13 ◽  
pp. 2561-2568 ◽  
Author(s):  
Dmitry Yu Vandyshev ◽  
Khidmet S Shikhaliev ◽  
Andrey Yu Potapov ◽  
Michael Yu Krysin ◽  
Fedor I Zubkov ◽  
...  
Keyword(s):  
Double Bond ◽  
Reaction Pathway ◽  
Synthetic Approach ◽  
Amino Group ◽  
The Novel ◽  
Two Stage ◽  
Intramolecular Recyclization

The novel cascade two-stage reaction between itaconimides and 1,2-diamino-4-phenylimidazole proceeds regio- and chemoselectively to form tetrahydroimidazo[1,5-b]pyridazines and includes nucleophilic C-addition by the activated C=C double bond and subsequent intramolecular recyclization of the intermediate with the amino group involved.

Porcine glutathione transferase Alpha 2-2 is a human GST A3-3 analogue that catalyses steroid double-bond isomerization

2010 ◽  
Vol 431 (1) ◽  
pp. 159-167 ◽  
Author(s):  
Natalia Fedulova ◽  
Françoise Raffalli-Mathieu ◽  
Bengt Mannervik
Keyword(s):  
Double Bond ◽  
Glutathione Transferase ◽  
Biological Species ◽  
Glutathione Transferases ◽  
Special Role ◽  
Primary Role ◽  
The Novel ◽  
Protective Function ◽  
Isomerase Activity

A primary role of GSTs (glutathione transferases) is detoxication of electrophilic compounds. In addition to this protective function, hGST (human GST) A3-3, a member of the Alpha class of soluble GSTs, has prominent steroid double-bond isomerase activity. The isomerase reaction is an obligatory step in the biosynthesis of steroid hormones, indicating a special role of hGST A3-3 in steroidogenic tissues. An analogous GST with high steroid isomerase activity has so far not been found in any other biological species. In the present study, we characterized a Sus scrofa (pig) enzyme, pGST A2-2, displaying high steroid isomerase activity. High levels of pGST A2-2 expression were found in ovary, testis and liver. In its functional properties, other than steroid isomerization, pGST A2-2 was most similar to hGST A3-3. The properties of the novel porcine enzyme lend support to the notion that particular GSTs play an important role in steroidogenesis.

A two-stage clustering-based cold-start method for active learning

2021 ◽  
Vol 25 (5) ◽  
pp. 1169-1185
Author(s):  
Deniu He ◽  
Hong Yu ◽  
Guoyin Wang ◽  
Jie Li
Keyword(s):  
Active Learning ◽  
Class Imbalance ◽  
Imbalanced Data ◽  
Cold Start ◽  
Classification Performance ◽  
The Novel ◽  
Two Stage ◽  
Minority Class ◽  
Novel Method ◽  
Multiple Clusters

The problem of initialization of active learning is considered in this paper. Especially, this paper studies the problem in an imbalanced data scenario, which is called as class-imbalance active learning cold-start. The novel method is two-stage clustering-based active learning cold-start (ALCS). In the first stage, to separate the instances of minority class from that of majority class, a multi-center clustering is constructed based on a new inter-cluster tightness measure, thus the data is grouped into multiple clusters. Then, in the second stage, the initial training instances are selected from each cluster based on an adaptive candidate representative instances determination mechanism and a clusters-cyclic instance query mechanism. The comprehensive experiments demonstrate the effectiveness of the proposed method from the aspects of class coverage, classification performance, and impact on active learning.

Solving the dilemma in supplier selection by the group of weight vector with kernel

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sifeng Liu ◽  
Tao Liu ◽  
Wenfeng Yuan ◽  
Yingjie Yang
Keyword(s):  
Decision Model ◽  
Weight Vector ◽  
Clustering Coefficient ◽  
The Novel ◽  
Two Stage ◽  
Content Type ◽  
Grey Clustering ◽  
Coefficient Vector ◽  
Overall Evaluation ◽  
Selection Decision

PurposeThe purpose of this paper is to solve the dilemma in the process of major selection decision-making.Design/methodology/approachFirstly, the group of weight vector with kernel has been defined. Then, the weighted comprehensive clustering coefficient vector was calculated based on the group of weight vector with kernel. Under the action of weighted comprehensive clustering coefficient vector, the information including in other components around component k and supporting object i to be classified into the k-th category has been gathered to component k. At last, a novel two-stage decision model based on the group of weight vector with kernel and the weighted comprehensive clustering coefficient vector is put forward to solve the dilemma in grey clustering evaluation. Then the overall evaluation conclusion can be consistent with the clustering result according to the rule of maximum value.FindingsA new way to solve the dilemma in the process of major selection decision-making has been found. People can obtain a consistent result with two-stage decision model at the case of dilemma. That is, the conclusion of the overall evaluation is consistent with the clustering result according to the rule of maximum value.Practical implicationsSeveral functional groups of weight vector with kernel have been put forward. The proposed model can solve the clustering dilemma effectively and produce consistent results. A practical application of decision problem to solve the dilemma in supplier evaluation and selection of a key component of large commercial aircraft C919 have been completed by the novel two-stage decision model.Originality/valueThe two-stage decision model, the group of weight vector with kernel and the weighted comprehensive clustering coefficient vector were presented in this paper firstly. People can solve the dilemma in grey clustering evaluation effectively by the novel two-stage decision model based on the group of weight vector with kernel and the weighted comprehensive clustering coefficient vector.

“Picture it all, Darley”

2015 ◽  
Vol 70 (1) ◽  
pp. 65-101 ◽  
Author(s):  
Sari Altschuler
Keyword(s):  
African Americans ◽  
Media History ◽  
The Novel ◽  
Two Stage ◽  
Race Politics ◽  
Current Events ◽  
History Of ◽  
The Media ◽  
Representational Limits ◽  
History Of Race

Sari Altschuler “‘Picture it all, Darley’: Race Politics and the Media History of George Lippard’s The Quaker City” (pp. 65–101) This essay adresses two related questions. First, how did George Lippard’s The Quaker City develop from a multimedia story told through newspaper conventions, illustration, and two plays into the novel that appeared in May 1845? And second, how did Lippard’s white-seduction narrative come to pivot around the nightmare of an ambiguously raced Devil-Bug? Joining these questions of form and content, I argue that the media history of The Quaker City is inextricable from its history of race. In the wake of the almost riot around the mid-serialization of his Philadelphia play, Lippard moved away from fictionalizing current events toward the “grotesque-sublime” through a broader critique of Philadelphia less open to charges of libel. This shift took place through the transformation of Devil-Bug, a character Lippard rapidly developed in the middle installments until he was complex enough to carry the new story. Turning the once-black Devil-Bug into his protagonist, however, required character developments that necessarily complicated the story’s representation of race, a process that occurred concurrently with events related to the work that highlighted the systemic oppression of African Americans. In winter 1844, troubles with two stage productions and his illustrator highlighted the problems of representing race. After a several-month hiatus, Lippard published new installments vituperously condemning the representational limits of these nonprose forms and turned to prose to develop his antislavery position through Devil-Bug. As a result of these confluent developments, The Quaker City became an antislavery text through the process of opening Devil-Bug’s character up to its own hybridity and interiority.

Generalized Disturbance Observer Synthesis Using a Two-Stage Heuristic Algorithm

2017 ◽  
Author(s):  
Guofei Xiang ◽  
Jianbo Su
Keyword(s):  
Disturbance Observer ◽  
Filter Design ◽  
Mimo Systems ◽  
Solution Space ◽  
The Novel ◽  
Two Stage ◽  
Design Algorithm ◽  
Reduced Order ◽  
Kyp Lemma ◽  
Low Pass

Disturbance observer (DOB) based control has been widely applied in industries due to its easy usage but powerful disturbance rejection ability. However, the existence of innate structure constraint, namely the inverse of the nominal plant, prevents its implementation on more general class of systems, such as non-minimum phase plants, MIMO systems etc.. Furthermore, additional limitations exerted on Q-filter design, i.e., unity steady state gain and low-pass nature, which narrow down its solution space largely and prevent from achieving optimal performance even if it exists. In this paper, we present a novel DOB architecture, named generalized disturbance observer (G-DOB), with the help of nontraditional use of the celebrated Youla parametrization of two degree-of-freedom controller. Rigorous analyses show that the novel G-DOB not only inherits all the merits of the conventional one, but also alleviates the limitations stated before partially. By some appropriate system manipulation, the synthesis of Q-filter has been converted to the design of reduced-order controller. Thus, a heuristic two-stage algorithm has been developed with the help of Kalman-Yakubovich-Popov (KYP) lemma: firstly design a full information controller for the augmented system and then compute a reduced-order controller. Numerical examples are presented to demonstrate the effectiveness of the proposed G-DOB structure and design algorithm.

The Reaction of 8-Amino-p-menthene Derivatives with Electrophiles

2004 ◽  
Vol 57 (6) ◽  
pp. 583
Author(s):  
Paul V. Bernhardt ◽  
Raymond M. Carman ◽  
Roger P. C. Derbyshire
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
The Novel

Attempts to ring-close the nitrogen atom of 8-amino-p-menth-1-ene and of N-substituted 8-amino-p-menth-1-enes onto the C1–C2 double-bond carbons has led to a range of bicyclo[2.2.2] and bicyclo[3.2.1] products, together with the novel bicyclo[4.3.1]-1,3-oxazepine 9.

scholarly journals Diversity-oriented synthesis of analogues of the novel macrocyclic peptide FR-225497 through late stage functionalization

2015 ◽  
Vol 11 ◽  
pp. 2487-2492 ◽  
Author(s):  
Jyotiprasad Mukherjee ◽  
Suman Sil ◽  
Shital Kumar Chattopadhyay
Keyword(s):  
Late Stage ◽  
Histone Deacetylase Inhibitor ◽  
Synthetic Approach ◽  
The Novel ◽  
Diversity Oriented Synthesis ◽  
Cross Metathesis ◽  
Naturally Occurring ◽  
Deacetylase Inhibitor ◽  
Structural Analogues ◽  
Macrocyclic Peptide

A concise synthetic approach to a class of biologically interesting cyclic tetrapeptides is reported which involves a late-stage functionalization of a macrocyclic scaffold through cross metathesis in an attempt to create diversity. The utility of this protocol is demonstrated through the preparation of three structural analogues of the important naturally occurring histone deacetylase inhibitor FR-225497.

Synthesis of a novel CB2 cannabinoid-porphyrin conjugate based on an antitumor chromenopyrazoledione

2017 ◽  
Vol 21 (01) ◽  
pp. 67-76 ◽  
Author(s):  
Paula Morales ◽  
Laura Moreno ◽  
Javier Fernández-Ruiz ◽  
Nadine Jagerovic
Keyword(s):  
Conformational Analysis ◽  
Ab Initio ◽  
Cannabinoid Receptor ◽  
Antitumor Agent ◽  
Synthetic Approach ◽  
The Novel ◽  
Absorption Intensity ◽  
Hartree Fock ◽  
Cannabinoid Receptor Type 2

With the objective of developing an antitumor agent, the synthesis of a chromenopyrazoledione conjugated to a tetraphenylporphyrin is described. A complete conformational analysis of the novel porphyrin conjugate was performed using ab initio Hartree–Fock calculations at the 6-31G* level. The novel conjugate (14) shows stronger absorption intensity for both Soret and Q-bands than the free meso-tetraphenylporphyrin. It binds weakly but selectively to the cannabinoid receptor type-2. During the synthetic approach, a new tetraphenylporphyrin, 5-[4-(3,5-dioxomorpholino)phenyl]-10,15,20-triphenylporphyrin (10), has been characterized.

Sign in / Sign up

Export Citation Format

Share Document