Theoretical study of electronic structures, magnetic properties, and ultrafast spin manipulation in transition metal adsorbed polycyclic-aromatic-hydrocarbon molecules.

We present a first-principles study of the structural, electronic, and magnetic properties of TM(PAH)0/+ (TM = Fe, Co, Ni; PAH = C10H8, C16H10, C24H12, C32H14) complexes and explore the laser-induced spin dynamics as well as their stability with respect to various laser parameters. For each complex, the most stable configuration shows that the TM atom prefers to adsorb at the hollow site of the carbon ring with a slight deviation from the center. The electronic structure and spin localization of the complexes are found to be largely affected by the TM type. Driven by various laser pulses, spin-crossover scenarios are achieved in all structures, while spin-transfer between TM and PAH is achieved in Ni(C10H8), Ni(C16H10), and Ni(C24H12). The influence of the laser energy and chirp on the dynamics is also investigated, providing important information regarding the stability and sensitivity of the dynamical process. All results are believed to reveal the physics nature of the TM-PAH systems, to guide the experimental realization of their ultrafast spin dynamics and thus to promote their applications in future spintronics.

[Progress of the application research of acupuncture anesthesia in thyroid surgery].

This article reviews the clinical studies on the application of acupuncture anesthesia in thyroid surgery over the past 5 years. Starting from the principle of acupuncture anesthesia, the authors explore the application of acupuncture anesthesia in thyroid surgery, its advantages and development. The summarized findings showed that acupuncture anesthesia has a better analgesic effect in thyroid surgery, which can reduce the occurrence of stress reactions, adverse reactions and complications, and is conducive to postoperative recovery. However, there is a lack of standardized operations. In the future, standardized operations can make acupuncture anesthesia more widely used and popularized.

Effect of aromatase inhibitor letrozole on the proliferation of spermatogonia by regulating the MAPK pathway.

The molecular mechanism of the aromatase inhibitor letrozole was investigated. It promotes the proliferation of spermatogonia by regulating the mitogen-activated protein kinase (MAPK) pathway. Six different concentrations were selected for letrozole in order to incubate mouse spermatogonia [GC-1 spermatogonia (spg)] for 24, 48 and 72 h, respectively. Cell Counting Kit-8 (CCK-8) was used to observe the effect of letrozole on the proliferation of GC-1 spg cells, and the effect was further verified by cell plate clone formation assay. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis were used to detect the effects of letrozole on MAPK signaling pathways [Ras/extracellular signal-regulated kinase 1 (ERK1)/c-Myc], proliferation indexes [Ki-67 and proliferating cell nuclear antigen (PCNA)]. Bromodeoxyuridine (BrdU) staining was used to study the effects of letrozole and MAPK signaling pathways on cell proliferation. The results of CCK-8 showed that the proliferation rate of GC-1 spg cells was improved. Study results also revealed a significant increase in letrozole concentration along with the time of action. The results of plate clone formation assay further indicated that letrozole could significantly promote the proliferation capacity of GC-1 spg cells (p<0.05). The results of RT-PCR and western blot analysis confirmed letrozole significantly activated the expression of Ras/ERK1/c-Myc in the classical MAPK pathway. A significant increase was noted in the protein levels of Ki-67 and PCNA (p<0.05). By contrast, inhibition of the MAPK pathway resulted in a significant decrease in the levels of the above indexes (p<0.05). The number of BrdU cells in the letrozole group was also higher than that of the control group, while the number of BrdU-stained cells in the letrozole + MAPK inhibition group showed a significant decrease in comparison to the letrozole group. In conclusion, letrozole activated the MAPK signaling pathway and promoted the proliferation of mouse spermatogonia GC-1 spg cells. The present study provides a theoretical basis for the clinical application of letrozole.