Periodontitis, especially in its chronic form, is one of the leading causes of tooth loss, significantly affecting the quality of life in the modern era of aging society. Recent studies have revealed a potential correlation between periodontitis and various systemic diseases, including cardiovascular diseases and Alzheimer’s dementia (AD). With the body of epidemiologic evidence that links these separate disease entities, several lines of hypotheses have been postulated to provide mechanistic understandings that mostly comprises abnormal regulation of immunologic and inflammatory signaling. In this review, we revisit the experimental findings that describe virulence factors derived from Porphyromonas gingivalis, including gingipains and lipopolysaccharides, as well as their roles in the pathophysiology of AD. In addition, we address potential immunologic challenges imposed by this bacterial pathogen contributing to progression of AD.

Zinc selenide (ZnSe) nanoparticles were synthesized in aqueous solution using glutathione (GSH) as a ligand. The influence of the ligand content, reaction temperature, and hydroxyl ion concentration (pH) on the fabrication of the ZnSe particles was investigated. The optical properties of the synthesized ZnSe particles were characterized using various analytical techniques. The nanoparticles absorbed UV-vis light in the range of 350-400 nm, which is shorter than the absorption wavelength of bulk ZnSe particles (460 nm). The lowest ligand concentration for achieving good light absorption and emission properties was 0.6 mmol. The reaction temperature had an impact on the emission properties; photoluminescence spectroscopic analysis showed that the photo-discharge characteristics were greatly enhanced at high temperatures. These discharge characteristics were also affected by the hydroxyl ion concentration in solution; at pH 13, sound emission characteristics were observed, even at a low temperature of 25oC. The manufactured nanoparticles showed excellent light absorption and emission properties, suggesting the possibility of fabricating ZnSe QDs in aqueous solutions at low temperatures.

Nano-sized ZnSe particles are successfully synthesized in an aqueous solution at room temperature using sodium borohydride (NaBH4) and thioglycolic acid (TGA) as the reducing agent and stabilizer, respectively. The effects of the mass ratio of the reducing agent to Se, stabilizer concentration, and stirring time on the synthesis of the ZnSe nanoparticles are evaluated. The light absorption/emission properties of the synthesized nanoparticles are characterized using ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy, and particle size analyzer (PSA) techniques. At least one mass ratio (NaBH4/Se) of the reducing agent should be added to produce ZnSe nanoparticles finer than 10 nm and to absorb UV–vis light shorter than the ZnSe bulk absorption wavelength of 460 nm. As the ratio of the reducing agent increases, the absorption wavelengths in the UV-vis curves are blue-shifted. Stirring in the atmosphere acts as a deterrent to the reduction reaction and formation of nanoparticles, but if not stirred in the atmosphere, the result is on par with synthesis in a nitrogen atmosphere. The stabilizer, TGA, has an impact on the Zn precursor synthesis. The fabricated nanoparticles exhibit excellent photo-absorption/discharge characteristics, suggesting that ZnSe nanoparticles can be alloyed without the need for organic solutions or high-temperature environments.

목적: 최근 원데이 소프트콘택렌즈 착용비율이 증가함에 따라 부작용 비율도 증가하고 있다. 이에 본 연구는 원데이 콘택트렌즈를 하루를 초과해서 착용했을 때 발생할 수 있는 여러 가지 문제점들에 대해 알아보고자 하였다. 방법: 전신질환 및 안과적 수술경험이 없고 실험의 취지를 이해하고 동의한 교정시력 1.0 이상의 남녀 23명을 대상으로 하였다. 원데이 소프트콘택트렌즈는 시중에서 가장 많이 유통되고 있는 A사 제품을 사용하였으며, 콘택트렌즈 피팅을 위한 전안부검사, 각막곡률검사, 굴절검사 후 피팅평가를 실시하여 1일, 2일, 3일 간의 자각적 만족도(건조감, 이물감, 흐림, 눈부심, 두통, 가려움증, 충혈 등)를 실시하였다. 또한 참가자의 눈 보호를 위해 3일간의 착 용기간 중에 전안부 검사를 통해 이상증상이 있을 경우 즉시 착용을 중단하였다. 결과: 원데이 일회용 콘택트렌즈 착용 1일차(12시간)는 대부분 무난하고 양호한 착용감을 보였으나, 2일차(24시간)에는 1일차 보다는 좀 더 불편한 착용감을 보였고, 3일차(36시간)에는 착용감이 급격히 떨어져 착용을 중단하는 참가자가 많았다. 1일차(12시간)~2일차(24 시간)는 자각적으로나 타각적으로나 문제가 발생하지 않았으나, 3일차 이후부터 자각증상에서 뻑뻑함과 건조감 부분에서 급속히 증상이 악화되었다. 결론: 원데이 일회용 콘택트렌즈의 착용감의 변화는 2일차부터 발생하며 렌즈의 표면침착물로 인해 3일차부터 착용자의 자각적 만족도가 급격히 낮아짐을 알 수 있었다. 따라서 원데이 일회용 콘택트렌즈는 착용기간을 준수하여야 할 것이다.