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。     

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.     

Freeze-all,for whom,when, and how

Background: The ‘freeze-all’ practice refers to the cryopreservation of all mature oocytes or viable embryos after ovarian stimulation. The development of the vitrification technique has been crucial to make this approach a reality, since it increases the post-thaw survival rates and permits comparable implantation rates with fresh embryos. Nonetheless, as implantation probabilities are comparable to fresh embryo transfer in normo-responder patients, the freeze- all strategy has demonstrated no benefits overall.Method: Narrative review in which we give an overview of this approach, discuss recent advances in the field, as well as for whom, when and how it is recommended to emply the freeze-all technique.Results: However, there is some clinical evidence that shows its feasibility. Thus, it has been demonstrated that elevation of progesterone at the end of ovarian stimulation decreases the implantation rates after the transfer of day 6 blastocysts in fresh and some uterine pathologies; freeze-all is also the preferred option for patients undergoing pre-implantation genetic testing, since there is an improvement of the results and it allows for inclusion of all blastocysts of the cohort. In high responders, the freeze-all strategy optimizes the response whilst also minimizing the risk of ovarian hyperstimulation syndrome.Conclusion: Due to the different cases that a reproductive expert might encounter, it is essential to highlight benefits and drawbacks of this practice.     

认识·知·意向性

认识是一多环节过程,"知"只是它的一个主观环节.但"知"(觉知)不是一个关系范畴,用关系机制说明不了"知"的义理,其本义乃是心理现象(观念)的自明或自肯定.因此,认识外部客观事物还需借助心理的意向性来完成.意向性是人通过感知与动作的协调过程而形成的,它有指向外物的特征.若深入理解,意向性实际也是一种整体觉知效应.