In the title complex, [Ru(C(12)H(8)N(2))(2)(C(5)H(6)N(2))(2)](PF(6))(2), the Ru(II) atom is bonded to two α-diimine ligands, viz. 1,10-phenanthroline (phen), in a cis configuration, in addition with with two 4-amino-pyridine (4Apy) ligands, resulting in a distorted octa-hedral coordination geometry. N-H⋯F hydrogen-bonding inter-actions play an important role in the crystal assembly: 2(1)-screw-...

In this communication, we will demonstrate that polymerization in a chiral solvent can affect the molecular weight distribution of the product by perturbing the balance of the P and M helical screw senses of the growing chains. Specifically, for the Wurtz-type synthesis of polymethylphenylsilane (PMPS) in either (R) or (S)-limonene, the weight-average molecular weight of the products (average M...

Abstract. In order to solve the problems of failure disposable tip insertion which happens in pipetting process most multi-station and high-throughput devices, this paper proposes a high-rigidity screw-type pipette shaft–disposable assembly mechanism with excellent auto-centering effects based on principle ball screw drive. The stiffness model new device is established, its axial deformation ar...

Until recently, it was assumed that any short DNA segment could be regarded as a straight rod. Many instances, however, have been reported in which the helical axis was curved. In this study, to gain a general insight into the structural features of sequence-directed DNA curvatures, we constructed a set of plasmids carrying curved DNA segments, which were randomly cloned from Streptomyces total...

Lead screws are the most commonly used transmission components in tool machinery and precision machinery, widely various industrial equipment instruments. However, screw tooth profile squeezes friction causes gear to break, surface wear, pitting other damage, which reduces service life of screw; use a large amount lubricants can not ignore environmental impact. The design research this subject ...

OBJECTIVES The objective of this clinical study was to evaluate the prosthetic complications of patients with 2 to 4 implants splinted with a round bar or with 2 to 4 unsplinted implants with ball attachments during the follow-up period. METHODS A total of 26 patients were included in this study. Patients were randomly provided with a round bar or with ball attachments that were used to retai...