见证 回味 感恩 展望

20年前的金秋,首都医科大学附属北京朝阳医院心脏中心诞生了。满怀豪情壮志的胡大一教授带着先进的技术、全新的理念、科学的管理、年轻的团队来到这里,经过艰苦的创业和科学的管理,打造出了国内首家真正意义上的心脏中心。北京朝阳医院心脏中心的诞生标志着融心脏内科、外科、介入于一体的一种全新的管理和运作模式。     

Tarsal functions, movement, and stabilization mechanisms in foot, ankle, and leg performance

The authors investigated the function of the tarsus and the skeletal segments of the foot in terms of the biomechanical significance of the individual links of the foot-ankle-leg complex. A performance model based on pressure-washed trabecular systems and the interface of the different segments making up the articular foot skeleton is presented and discussed. The biomechanical influence of these segments on each other and on their appendicular companion bones is assessed, and an explanation of their function is provided.     

Solid and liquid state characterization of tetrahydrocurcumin using XRPD,FT-IR,DSC, TGA,LC-MS,GC-MS,and NMR and its biological activities

Tetrahydrocurcumin (THC) is one of the major metabolites of curcumin (CUR), an ancient bioactive natural polyphenolic compound. This research article describes both the solid and liquid state characterization of THC using advanced spectroscopic and thermo-analytical techniques. Anti-inflammatory, anti-oxidant, and neuroprotective activities of THC were investigated using in vitro cell lines. Liquid chromatography-mass spectrometry analysis revealed that our sample comprised 95.15% THC, 0.51% tetrahydrodemethoxycurcumin (THDC), 3.40% hexahydrocurcumin, and 0.94% octahydrocurcumin. Gas chromatography-mass spectrometry analysis indicated the presence of 96.68% THC and 3.32% THDC. THC in solution existed as keto-enol tautomers in three different forms at different retention time, but the enol form was found to be dominant, which was also supported by nuclear magnetic resonance analysis. THC was thermally stable up to 335.55 °C. THC exhibited more suppression of cytokines (TNF-α, IL-1β, and MIP-1α) than CUR in a concentration-dependent manner in mouse splenocytes, while NK-cell and phagocytosis activity was increased in macrophages. THC showed a significant reduction of free radicals (LPO) along with improved antioxidant enzymes (SOD and catalase) and increased free radical scavenging activity against ABTS⁺ radicals in HepG2 cells. THC displayed higher protection capability than CUR from oxidative stress and neuronal damage by improving cell viability against H₂O₂ induced HepG2 cells and MPP⁺ induced SH-SY5Y cells, respectively, in a concentration-dependent manner. Thus, a variation of the biological activities of THC might rely on its keto-enol form and the presence of other THC analogs as impurities. The present study could be advantageous for further research on THC for better understanding its physicochemical properties and biological variation.