Two-minute walk distance reference equations for middle-aged and elderly Chinese individuals with obesity.

BACKGROUND AND OBJECTIVE: While the six-minute walk test (6MWT) is often used to assess exercise capacity, the less well-known two-minute walk test (2MWT) is more feasible for some patients. In previous studies, we developed reference equations for the two-minute walk distance (2MWD) for healthy Chinese adults. However, our study did not recruit people with obesity, and the reference equations did not apply to participants with a body mass index (BMI) > 30 kg/m2. The main objective of this study was to establish reference equations for the 2MWD among middle-aged and elderly Chinese individuals with obesity. METHODS: A total of 295 individuals were recruited. The participants underwent two 2MWTs, with the longer of the two 2MWDs used for further analyses. The reference equations for the 2MWD were developed using stepwise multiple regression analysis. The newly established equations for the 2MWD were then compared with the existing equations. RESULTS: The mean 2MWD of the participants was 176±20 m. Age and BMI were identified as independent factors that influenced the 2MWD and explained 28% and 32% of the variance in walking distance for the male and female groups, respectively. The reference equations for the 2MWD were as follows: [Formula: see text]. CONCLUSION: This study resulted in the development of reference equations for predicting 2MWD among middle-aged and elderly Chinese people with obesity. These equations will be a clinically valuable tool for evaluating functional capacity, determining prognoses and monitoring treatment in middle-aged and elderly Chinese people with obesity.

Silver salt enabled H/D exchange at the ß-position of thiophene rings: synthesis of fully deuterated thiophene derivatives.

We disclose a silver catalyzed H/D exchange reaction, which can introduce the deuterium atom at the ß position of thiophene rings without the assistance of any coordinating groups. The advantages of this reaction include operation in open air, usage of D2O as the deuterium source, good tolerance to a range of functional groups and obtaining high atom% deuterium incorporation. In addition, this H/D exchange reaction is employed for direct deuteration of a thiophene based monomer, which is usually prepared by multistep synthesis from expensive deuterated starting materials.

Synthesis of Multideuterated (Hetero)aryl Bromides by Ag(I)-Catalyzed H/D Exchange.

Deterium-labeled (hetero)aryl bromide is one of the most widespread applicable motifs to achieve important deuterated architectures for various scientific applications. Traditionally, these deterium-labeled (hetero)aryl bromides are commonly prepared via multistep syntheses. Herein, we disclose a direct H/D exchange protocol for deuteration of (hetero)aryl bromides using Ag2CO3 as catalyst and D2O as deuterium source. This protocol is highly efficient, simply manipulated, and appliable for deuterium-labeling of over 55 (hetero)aryl bromides including bioactive druglike molecules and key intermediates of functional materials. In addition, this method showed distinguishing site-selectivity toward the existing transition-metal-catalyzed HIE process, leading to multideuterated (hetero)aryl bromides in one step.

Ultrahigh Adhesion Force Between Silica-Binding Peptide SB7 and Glass Substrate Studied by Single-Molecule Force Spectroscopy and Molecular Dynamic Simulation.

Many proteins and peptides have been identified to effectively and specifically bind on certain surfaces such as silica, polystyrene and titanium dioxide. It is of great interest, in many areas such as enzyme immobilization, surface functionalization and nanotechnology, to understand how these proteins/peptides bind to solid surfaces. Here we use single-molecule force spectroscopy (SMFS) based on atomic force microscopy to directly measure the adhesion force between a silica-binding peptide SB7 and glass surface at single molecule level. SMFS results show that the adhesion force of a single SB7 detaching from the glass surface distributes in two populations at ~220 pN and 610 pN, which is higher than the unfolding forces of most mechanically stable proteins and the unbinding forces of most stable protein-protein interactions. Molecular dynamics simulation reveals that the electrostatic interactions between positively charged arginine residues and the silica surface dominates the binding of SB7 on silica. Our study provides experimental evidence and molecular mechanism at the single-molecule level for the SB7-based immobilization of proteins on silica-based surface, which is able to withstand high mechanical forces, making it an ideal fusion tag for silica surface immobilization or peptide-base adhesive materials.

Ag(i)-Mediated hydrogen isotope exchange of mono-fluorinated (hetero)arenes.

An efficient approach to install deuterium into mono-fluorinated (hetero)arenes by a Ag2CO3/Sphos-mediated HIE protocol with D2O as the deuterium source has been disclosed. This method showed a specific site selectivity of deuteration at the α-position of the fluorine atom, which is complementary to the existing transition metal-catalyzed HIE process.

Ag2CO3-Catalyzed H/D Exchange of Five-Membered Heteroarenes at Ambient Temperature.

Ag2CO3-catalyzed hydrogen isotope exchange of five-membered heteroarenes is disclosed. The reaction can be conducted in the open air, at ambient temperature, and with D2O as deuterium source. Moreover, this protocol showed orthogonal site selectivity to existing technology, thereby greatly expanding the scope of substrates for HIE reaction. The mechanistic study indicated that the carbonate group plays a crucial role to achieve high levels of deuterium incorporation by lowering the activation energy of H/D exchange process.