The Effect of Inhibitors and Catalysts in the Synthesis of 2- Hydroxyethyl Methacrylate(2-HEMA)

2-Hydroxyethyl methacrylate(2-HEMA)의 합성에 있어서 중합억제제와 촉매의 영향에 대해서 조사하였다. 촉매로서 triethylamine(TEA), FeCl3·6H2O, Cu(NO3)2, 2H2O, AlCl3, Na2Cr2O7을 선택하였으며, 중합억제제로는 p-Methoxyphenol(PMP) 또는 NaNO3 수용액을 각각 사용하였다. NaNO3 수용액을 중합억제제로 사용한 경우, triethylamine(TEA), FeCl3·6H2O, NaCr2O7는 좋은 촉매 효과를 보여 주었다. p-Methoxyphenol(PMP)를 중합억제제로 사용한 경우, 반응은 매우 느렸고 PMP가 Fe3+ 또는 Cr6+ 이온을 환원시키기 때문에 효과적이지 못했다. 이와는 달리, NaNO3수용액을 중합억제제로 사용한 경우, 반응은 매우 빨랐으며 금속 촉매의 비활성화도 없었다. The effect of inhibitors and catalysts in the synthesis of 2-hydroxyethyl methacrylate(2-HEMA) was studied. As catalysts, triethylamine(TEA), FeCl3·6H2O, Cu(NO3)2, 2H2O, AlCl3, Na2Cr2O7 were selected. p-Methoxyphenol (PMP) of aq. NaNO7 solution was used as an inhibitor in polymerization. in aq. NaNO3 inhibitor system, triethylamine (TEA), FeCl3·6H2O, and Na2Cr2O7, showed good catalytic effects. When p-methoxyphenol(PMP) was used as a polymerization inhibitor, the reaction was very sluggish and noneffective because the metal ion such as Fe3+or Cr6+ was reduced by PMP. On the contrary, when aq. NaNO3 was used as an inhibitor in polymerization, the reaction was very fast without deactivation of the metal catalysts

Morphological changes in the superficial medial collateral ligament on knee MR imaging: association with medial meniscal extrusion and posterior root medial meniscus abnormality

© 2021, ISS.Objective: To assess the association between morphological changes in the superficial medial collateral ligament and meniscal extrusion with medial meniscus posterior root tear. Materials and methods: From January 1, 2018, to December 31, 2019, 124 patients who underwent knee MRI within 90 days prior to knee surgery and whose medial meniscus surgically proved intact, with posterior root tear or posterior horn tear, were enrolled. Two radiologists who were blinded to the surgical results assessed the morphological changes in the superficial medial collateral ligament, including thickness, bowing angle, and presence of signal intensity alteration, and medial meniscus extrusion, according to the presence of tears in the posterior root of the medial meniscus or posterior horn of the medial meniscus using the chi-square test, one-way ANOVA, and Cohens kappa test. Results: Thirty-six posterior root tears, 31 posterior horn tears, and 57 intact medial menisci were observed surgically. The mean values of thickness showed no significant differences among the three groups. The bowing angle was significantly higher in the posterior root tear than in the posterior horn tear (reader 1 = 0.001, reader 2 = 0.002) and normal meniscus groups (readers 1 and 2 < 0.001). The percentage of superficial medial collateral ligament signal intensity alteration and meniscal extrusion was highest in the group with posterior root of the medial meniscus tear (80.6% and 94.4%, respectively) and lowest in the group with normal medial meniscus (17.5% and 10.5%, respectively). Conclusion: Morphological changes in the superficial medial collateral ligament and meniscal extrusion were associated with medial meniscus posterior root tears.N

Comparative fine structure of the epididymal spermatozoa from three Korean shrews with considerations on their phylogenetic relationships

This study examined the fine structures of epididymal spermatozoa on the lesser white-toothed shrew (Crocidura suaveolens), the Japanese white-toothed shrew (C. dsinezumi) and the big white-toothed shrew (C. lasiura) belonging to the subfamily Crocidurinae living in Korea. In the spermatozoa of C. suaveolens, the head has a large acrosome, a smooth inner acrosomal membrane and a wavy, finger-like, electron-dense apical body. The neck has a solid proximal centriole that is filled with electron-dense material. These results showed the spermatozoa of C. suaveolens possess the characteristics of both Crocidurinae and Soricinae. In C. dsinezumi and C. lasiura, the head has a large acrosome, a serrated inner acrosomal membrane and a common apical body. The neck has a fistulous proximal centriole with slightly dense electron granules. These results showed the typical characteristics of Crocidurinae. Although C. suaveolens belongs to the subfamily Crocidurinae, the spermatozoan morphology is different from C. dsinezumi and C.lasiurai because it has conserved characteristics of the subfamily Soricinae

Liver abscess and sepsis with Bacillus pantothenticus in an immunocompetent patient: A first case report

Bacillus species are aerobic, gram-positive, spore forming rods that are usually found in the soil, dust, streams, and other environmental sources. Except for Bacillus. anthracis (B. anthracis), most species display low virulence, and only rarely cause infections in hosts with weak or damaged immune systems. There are two case reports of B. cereus as a potentially serious bacterial pathogen causing a liver abscess in an immunologically competent patient. We herein report a case of liver abscess and sepsis caused by B. pantothenticus in an immunocompetent patient. Until now, no case of liver abscess due to B. pantothenticus has been reported