There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Support materials for PEMFC and DMFC electrocatalysts—A review

Over the past few decades, direct methanol fuel cells (DMFCs) have been intensively developed as clean and high-efficiency energy conversion devices. However, their dependence on expensive Pt-based catalysts for both the anode and the cathode make them unsuitable for large-scale commercialisation. The essential solution to addressing this shortfall is the development of low-Pt and non-Pt catalysts. Regarding this issue, considerable advances have been made with low-Pt alloys and core-shell-like catalysts, as well as non-platinum Pd–Me, Ru–Se and heat-treated MeNxCy-based catalysts. This perspective reviews potential pathways for increasing the cost-effectiveness and efficiency of these catalysts. Fundamental understanding of the composition–activity and structure–activity relationships, innovative synthesis, and promising developmental directions are highlighted. Regarding durability, the main degradation mechanism of these catalysts and the corresponding mitigating strategies are presented.

Recent advances in catalysts for direct methanol fuel cells

Review on the criteria anticipated for the fabrication of highly efficient ZnO-based visible-light-driven photocatalysts

Purpose To investigate the therapeutic effect of lipoxin A4 (LXA4) on Aspergillus fumigatus (A. fumigatus)–stimulated human corneal epithelial cells (HCECs). Methods The cell counting kit-8 (CCK-8) was performed in HCECs to evaluate the toxicity of LXA4. A cell scratch test was used to assess the impact of LXA4 on the migration of HCECs. Enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), and western blot were applied to examine the expression of inflammatory mediators in A. fumigatus–stimulated HCECs. The nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation and expression in HCECs were detected by immunofluorescence staining. Results LXA4 at 0–10 nmol·L-1 (nM) had no significant cytotoxic effect on HCECs. LXA4 at a concentration of 1 nM and 10 nM significantly promoted the migration rate of HCECs. The mRNA and protein levels of pro-inflammatory mediators, including IL-1β, TNF-α, and IL-6, were remarkably lower in the LXA4-treated group. LXA4 promoted the expression of Nrf2 and heme oxygenase 1 (HO-1) in A. fumigatus–stimulated HCECs compared with the PBS control group. Pretreatment with brusatol (BT, Nrf2 inhibitor) or Zine Protoporphyrin (Znpp, HO-1 inhibitor) receded the anti-inflammatory ability of LXA4. Conclusions LXA4 plays a protective role in A. fumigatus–stimulated HCECs by inhibiting the expression of pro-inflammatory mediators through the Nrf2/HO-1 signaling pathway.

Lipoxin A4 alleviates inflammation in Aspergillus fumigatus–stimulated human corneal epithelial cells by Nrf2/HO-1 signaling pathway

An electromagnetic excitation method of compression waves is proposed, in which a static magnetic field and an alternating current are simultaneously imposed on a liquid metal. The comparison between measured pressures in the liquid metal and the theoretically derived pressures has shown good agreement. The effect of compression waves on the refinement of solidified structures of a Sn-Pb alloy has been also studied. The whole region in a specimen was refined by using the proposed method while grain sizes without compression waves were large.

Supersonic wave generation in a conductive liquid by local imposition of alternating electromagnetic force

Specific chemical and physical properties of alloy nanoparticles have led to their widespread application in catalysts, sensors, and microelectronic and optoelectronic devices. These properties can be tuned by their size and nanoparticle constituents. The atomic behavior and structural evolution of alloy nanoparticles play a key role in providing them with the required properties. The surface energies between two random elements are different. The atoms with lower surface energy segregate to the nanoparticle surface to decrease the system free energy. This segregation usually leads to different atomic behaviors that result in different structure and property evolutions. Therefore, research into the atomic behavior of alloy nanoparticles during their formation essential encompasses understanding how to tune their properties. This chapter focuses on the effects of atomic segregation on changes in melting and structure of alloy nanoparticles during heating and also on the influence of atomic behavior on freezing and coalescence of their structure. Molecular dynamics simulations with a general embedded atom method were used to study atomic behavior and structural evolution. We discuss the development of atomic behavior and structural evolution of alloy nanoparticles in Section 9.1 , the simulation method in Section 9.2 , and the results and discussion in Section 9.3 . This section includes the influence of atomic segregation on melting and nanoparticle structure evolution and the effect of atomic behavior on the coalesced structures. In Section 9.4 , we summarize the conclusions and outlook. Finally, a description of sources for further information and references are provided.

Atomic behavior and structural evolution of alloy nanoparticles during thermodynamic processes

Fabrication and Simulation of a Two-Stage Mold with Low Magnetic Shielding for Soft-Contact Electromagnetic Continuous Casting

The main features of polycystic ovary syndrome (PCOS) are abnormal follicular development and ovulatory dysfunction, which are caused by excessive apoptosis of ovarian granulosa cells. Acupuncture has been shown to improve follicular development abnormalities in patients with PCOS, but its mechanism is unknown. This study hypothesized that the mechanism of acupuncture on follicular development abnormalities in PCOS patients is the inhibition of granulosa cell apoptosis through LncMEG3-mediated regulation of miR-21-3p.A PCOS-like rat model was established using subcutaneous injection of dehydroepiandrosterone (DHEA). Acupuncture was performed on rats for 15 d (CV-4, RN-3, CV-6, SP-6 and EX-CA 1). Ovarian morphology was observed by HE staining, and sex hormone and AMH levels were detected by ELISA. Primary granulosa cells were isolated from each group of rats to assess the association of acupuncture treatment, LncMEG3, miR-21-3p, and granulosa cell apoptosis in rats with PCOS.LncMEG3 and miR-21-3p were highly expressed in the ovarian granulosa cells of rats with PCOS, and LncMEG3-mediated regulation of miR-21-3p was involved in the development of PCOS in rats. Silencing of MEG3 attenuated sex hormone dysregulation and ovarian histopathological changes in PCOS rats and promoted follicle cell development and maturation. In addition, silencing MEG3 increased the viability and number of granulosa cells. In addition, silencing MEG3 further inhibited early and late apoptosis of ovarian granulosa cells in PCOS rats. Acupuncture improved polycystic ovarian morphology and sex hormone levels in PCOS rats. Acupuncture intervention increased the viability and number of granulosa cells. Acupuncture intervention inhibited early and late apoptosis of ovarian granulosa cells in PCOS rats by targeting miR-21-3p via LncMEG3.These results suggest that acupuncture can downregulate LncMEG3, thereby targeting and regulating miR-21-3p to suppress early and late granulosa cell apoptosis and normalize their proliferation. These factors ultimately compensate for abnormal follicular development. These findings shed light on the clinical potential of acupuncture as a safe treatment for follicular developmental abnormalities in PCOS. 

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Acupuncture regulates the apoptosis of ovarian granulosa cells in polycystic ovarian syndrome-related abnormal follicular development through LncMEG3-mediated inhibition of miR-21-3p

Qiang Wang

Papers

Lipoxin A4 alleviates inflammation in Aspergillus fumigatus–stimulated human corneal epithelial cells by Nrf2/HO-1 signaling pathway

Supersonic wave generation in a conductive liquid by local imposition of alternating electromagnetic force

Atomic behavior and structural evolution of alloy nanoparticles during thermodynamic processes

Fabrication and Simulation of a Two-Stage Mold with Low Magnetic Shielding for Soft-Contact Electromagnetic Continuous Casting

Acupuncture regulates the apoptosis of ovarian granulosa cells in polycystic ovarian syndrome-related abnormal follicular development through LncMEG3-mediated inhibition of miR-21-3p