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  • Author: Kang Da x
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Intramolecular hydrogen bonding in oligomeric aromatic amides may induce the backbones to adopt folded, zigzag, or other extended conformations, depending on the positions of the amide units and the hydrogen-bonding sites on the aromatic rings. This article summarizes our efforts in exploring the applications of this family of preorganized oligomers in supramolecular and materials chemistry. Several series of preorganized frameworks or foldamers have been developed as efficient acyclic receptors for binding both neutral and ionic guests. The backbones have been modified with discrete functional groups from the ends or the side chains. The resulting molecules have been applied for designing new molecular tweezers, assembling ordered supramolecular architectures (organogels and vesicles), and directing the formation of complicated macrocyclic and capsular systems. When the hydrogen-bonded folded segments are connected to n-butyl methacrylate copolymers as cross-links, the resulting copolymers display unique reversible mechanical properties owing to the breaking and recovering of the intramolecular hydrogen bonds. When the folded segments are incorporated into the dumbbell components of the donor–acceptor interaction-based pseudo[2]rotaxanes and [2]rotaxanes, they are capable of tuning the slippage/deslippage and switching of the ring component between the discrete “stations” in their dumbbell component.

Abstract

Databases play an important role in various computational techniques, including virtual screening (VS) and molecular modeling in general. These collections of molecules can contain a large amount of information, making them suitable for several drug discovery applications. For example, vendor, bioactivity data or target type can be found when searching a database. The introduction of these data resources and their characteristics is used for the design of an experiment. The description of the construction of a database can also be a good advisor for the creation of a new one. There are free available databases and commercial virtual libraries of molecules. Furthermore, a computational chemist can find databases for a general purpose or a specific subset such as natural products (NPs). In this chapter, NP database resources are presented, along with some guidelines when preparing an NP database for drug discovery purposes.

Abstract

Databases play an important role in various computational techniques, including virtual screening (VS) and molecular modeling in general. These collections of molecules can contain a large amount of information, making them suitable for several drug discovery applications. For example, vendor, bioactivity data or target type can be found when searching a database. The introduction of these data resources and their characteristics is used for the design of an experiment. The description of the construction of a database can also be a good advisor for the creation of a new one. There are free available databases and commercial virtual libraries of molecules. Furthermore, a computational chemist can find databases for a general purpose or a specific subset such as natural products (NPs). In this chapter, NP database resources are presented, along with some guidelines when preparing an NP database for drug discovery purposes.

Abstract

The blade deformation caused by aerodynamic and centrifugal loads during operating makes blade configurations different from their stationary shape. Based on the load incremental approach, a novel pre-deformation method for cold blade shape is provided in order to compensate blade deformation under running. Effect of nonlinear blade stiffness is considered by updating stiffness matrix in response to the variation of blade configuration when calculating deformations. The pre-deformation procedure is iterated till a converged cold blade shape is obtained. The proposed pre-deformation method is applied to a transonic compressor rotor. Effect of load conditions on blade pre-deformation is also analyzed. The results show that the pre-deformation method is easy to implement with fast convergence speed. Neither the aerodynamic load nor centrifugal load can be neglected in blade pre-deformation.

Abstract

In the present study, we examined the effect of single nucleotide polymorphisms (SNPs) of leptin (LEP), skeletal muscle glycogen synthase (GYS1), myogenic differentiation 1 (MYOD1), and myogenic factor 5 (MYF5) genes on economic trait association in pigs. LEP/HindIII, MYOD1/DdeI, MYF5/FokI, and GYS1/FokI genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) from 466 pigs comprised of Duroc, Landrace and Yorkshire breeds. The LEP/HindIII polymorphism differed significantly with respect to average daily gain (ADG) in Duroc pigs (P<0.05). However, the GYS1/FokI polymorphism was not significantly associated with any trait. The MYOD1/DdeI polymorphism was significantly associated with both ADG and meat percentage (MP) in Duroc pigs, and ADG, backfat thickness (BFT) and feed efficiency (FE) in Landrace pigs, whereas the MYOD1/DdeI polymorphism was not significantly associated with any trait in Yorkshire pigs. In addition, the MYF5/FokI polymorphism revealed a close relationship with ADG in Duroc pigs. In conclusion, we believe that the SNPs within LEP, MYOD1 and MYF5 in certain pig breeds play important roles as potential genetic markers for economic traits of pigs.