Cracks are an inevitable problem during the use of materials, and flexible sensors with self-healing capability are of great importance for applications in wearable devices and skin-like electronic devices. This paper prepared self-healing flexible strain sensors by compounding self-healing polyurethane with carbon nanotubes. First, by changing the ratio of disulfide bonds, a good balance between mechanical properties and self-healing efficiency was achieved in the prepared self-healing polyurethane. The most balanced sample reached 12.28 MPa in tensile strength, after 24 h of self-repair at 30 °C, the tensile strength was 7.75 MPa, and the self-repair efficiency was 63.11%; after 24 h of self-repair at 80 °C, the tensile strength was 11.64 MPa, and the self-repair efficiency reached 94.79%. Then the sensors prepared by compounding with carbon nanotubes showed a good electrochemical response, and both slow and fast repeated bending of the finger wearing the sensors yielded significantly different electrical signal changes, and the sensors were cut off and still had the same function after self-repair at 30 °C, demonstrating their excellent potential for applications in soft robots, wearable devices, etc.

Tungsten disulfide (WS2) nanosheets have attracted considerable attention because of their unique optical and electrical properties. Several methods for fabrication of WS2 nanosheets have been developed. However, methods for mass production of high-quality WS2 nanosheets remain challenging. In this study, WS2 nanosheets were fabricated using mechano-chemical ball milling based on the synergetic effects of chemical intercalation and mechanical exfoliation. The ball-milling time was set as a variable for the optimized fabricating process of WS2 nanosheets. Under the optimized conditions, the WS2 nanosheets had lateral sizes of 500–600 nm with either a monolayer or bilayer. They also exhibited high crystallinity in the 2H semiconducting phase. Thus, the proposed method can be applied to the exfoliation of other transition metal dichalcogenides using suitable chemical intercalants. It can also be used with highperformance WS2-based photodiodes and transistors used in practical semiconductor applications.

The differentiation of leukemia cells into mature cells is a major target of the human leukemia therapy. As differentiated leukemia cells lose their proliferative and tumor-forming abilities, differentiation inducers may be useful for the treatment of leukemia. In this study, the experiments were designed to determine whether diallyl disulfide (DADS) regulates expressions of tumor suppressor protein PTEN (phosphatase and tension homologue) in HL- 60 cells. DADS causes upregulation of PTEN in a time- and dose-dependent manner, which was correlated with decrease of phospho-Akt level. These results suggest that DADS induces upregulation of PTEN in human leukemia cells. These results suggest that DADS may be a useful anticancer agent for management of human leukemia.

The insect baculovirus expression vector system (BEVS) is useful for the production of biologically active recombinant proteins. However, the overexpression of foreign proteins in this system often results in misfolded proteins and the formation of protein aggregates. To overcome this limitation, we have developed a versatile baculovirus expression and secretion system using the Bombyx mori protein disulfide isomerase (bPDI) as a fusion partner. bPDI gene fusion improved the secretion and antibacterial activity of recombinant nuecin proteins. Thus, bPDI gene fusion is a useful addition to the BEVS for the large-scale production of bioactive recombinant proteins.

본 연구는 食品衛生과 環境衛生상 주요 危害因子중의 하나인 카드뮴에 대하여 식품으로서 섭취기회가 많은 마늘성분과 비타민 A를 이용한 危害 경감 혹은 방어효과를 평가하고, 카드뮴暴露에 대한 細胞水準의 反應으로서 HSP(Heat Shock Protein, 熱衝擊蛋白質 혹은 스트레스蛋白質)의 發顯時期와 發顯程度를 관찰하고자 실시하였다. 실험동물로는 Wistar계 SPF 수컷 랫드 483마리를 사용하였으며, 對照群, 카드뮴投與群(Cd, CdCl₂20 ㎎/㎏), 카드뮴과 마늘유 (diallyl disulfide) 投與群(Cd+Dds, diallyl disulfide 50 ㎎/㎏), 카드뮴과 비타민 A(retinol acetate) 投與群(Cd+Ra, retinol acetate 50,000 I.U./㎏)으로 구분하였다. 시험물질은 시간 간격에 따라 1, 2, 4, 8, 16, 24시간, 2, 4. 7일, 2, 4, 8, 16주에 投與하였으며, 관찰한 결과는 다음과 같다. 1. 카드뮴投與 後 4시간에 血中 카드뮴含量이 0.972∼l.256 ㎍/g으로 對照群의 0.004㎍/g에 비하여 높아졌으며, 投與 2주까지는 肝臟의 카드뮴含量이 23.76∼24.84 ㎍/g으로 腎臟의 20.53∼22.03 ㎍/g보다 높았으나, 8주 후부터는 肝臟의 카드뮴含量(82.48∼86.37 ㎍/g)보다 腎臟의 카드뮴含量(98.0∼109.8 ㎍/g)이 더 높았다. 따라서, 카드뮴은 投與 後 4시간에 혈액 중에 높게 나타나고, 점차 肝臟으로 이동하며 다시 肝臟에서 腎臟으로 이동함으로써, 8주 이후에는 肝臟보다 腎臟의 카드뮴 蓄積量이 많아지는 것으로 나타났다. 2. 카드뮴投與에 의한 血淸중의 酸素 變化에서 ALT(Alanine Aminotransferase), AST(Aspartate Aminotransferase) 活性度는 投與 後 1주일부터 각자 60.3∼73.0 U/ℓ, 135.5∼149.8 U/ℓ로 증가했지만 肝臟 毒性을 일으키는 정도는 아니었으며, glucose는 投與 8주에 對照群(113.8 ㎎/㎗)에 비하여 Cd+Ra群을 제외한 모든 群에서 72.8∼77.5 ㎎/㎗의 낮은 결과를 보여 대조군과 투여군간의 통계학적 有意性(p<0.05)을 보였다. BUN(blood urea nitrogen)은 投與 4주에 對照群의 19.3 ㎎/㎗에 비하여 Cd, Cd+Dds群에서 24.8∼25.8 ㎎/㎗ 有意한 증가를 보였으나, Cd+Ra群에서는 投與 16주에, Cd群의 33.2 ㎎/㎗에 비하여 27.3 ㎎/㎗으로 有意하게(p<0.05) 낮았다. Creatinine은 모든 試驗群에서 投與 8주에 對照群의 0.77 ㎎/㎗에 비하여 0.98∼1.38 ㎎/㎗로 높은 증가를 보였으며(p<0.05), 16주에는 Cd群의 1.20 ㎎/㎗에 비하여 Cd+Ra群은 1.02 ㎎/㎗로 有意하게 낮은 결과를 보였다(p<0.05). 3. 病理組織學적 檢査 결과 Cd群과 Cd+Ra群에서는 投與 8주부터 腎臟細尿管의 內腔에 好酸性顆粒이나 尿圓柱(urinary cast)가 관찰되었으며, Cd+Dds群은 腎臟 近位細尿管 上皮細胞에 顯著한 變性壤死가 나타났다. ??丸은 카드뮴投與 8주부터 精細管(seminiferous tubule) 사이의 間質組織이 好酸性 液體의 貯留에 의해 확장되어 주위의 精細管이 심하게 萎縮되는 등의 소견을 보였다. Cd+Dds群과 Cd+Ra群에서는 Cd群보다 病變이 微弱하였다. 카드뮴을 2주동안 投與한 랫드에서 腎臟의 電子顯微鏡 所見은 近位曲細尿管 細胞의 細胞質 腫脹, 미토콘드리아의 變性, 蛋白質 小球의 증가, 毛細血管 內皮細胞의 細胞質 腫脹과 空砲形成등이 관찰되기 시작하였으며, 投與 8주에 나타난 腎臟細尿管 內腔의 無形質 小球는 탈락된 變性 上皮細胞인 것으로 확인되었다. 4. HSP_(70)은 카드뮴投與 後 2시간부터 發顯이 증가되어, 48시간까지 持續되며, 이후에 原狀態로 恢復되는 것으로 나타났다. 위와같은 HSP_(70)의 發顯은 diallyl disulfide와 retinol acetate 投與에 의해 영향을 받지 않았다. 腎臟에서의 HSP_(70) 發顯은 絲球體와 細尿管上皮細胞에서 주로 發顯되는 것으로 나타났다. 이상의 결과로부터, 랫드에 카드뮴을 投與하였을 때 HSP_(70) 發顯은 投與 後 2∼4시간 내에 나타나는 迅速한 反應임을 알 수 있었고, 마늘유(diallyl disulfide) 投與는 카드뮴에 의한 腎臟損傷을 促進시키나, 비타민 A(retinol acetate) 投與는 카드뮴에 의한 腎臟損傷을 抑制시키는 효과를 보였다. 카드뮴에 의한 ??丸손상은 마늘유(diallyl disulfide) 흑은 비타민 A(retinol acetate)를 投與함으로써 損傷 防禦效果를 보였다.

Protein disulfide isomerase (PDI) is a chaperone protein that involves in oxidative protein folding by acting as catalysts and folding assistants in the endoplasmic reticulum (ER). Genome database showed that rice contains three PDI-like genes. But, their functions and subcellullar localization are not clearly identified. Here, we show possible functions of rice PDI (OsPDI) during seed development. Seeds of OsPDI T-DNA insertion mutants which were identified by genomic DNA PCR and western blot display chalky phenotype. Electron microscope analysis revealed that endosperms of the OsPDIL1-1Δ mutant show imperfect packing of round starch granules, causing floury-white color. Abnormal form of protein body I (PB-I) containing prolamin and thick aleurone layer were also observed in the OsPDIL1-1Δ mutants. Protein content per seed was significantly low in the OsPDIL1-1Δ mutant. However, free sugar content was high in the OsPDIL1-1Δ mutant seed. Northern and western blot analyses showed that during seed development, OsPDI protein is steadily accumulated in the seed until maturation while its transcript level was highest at 10 days after flowering and rapidly decreased to basal level. In addition, OsPDI strongly interacts with cysteine protease OsCP1 and chaperone BiP protein accumulates in OsPDIL1-1Δ mutant. Besides, proteomic analysis of the OsPDIL1-1Δ mutant seed showed that OsPDI is post-translationally regulated and its loss causes accumulation of many types of seed proteins. Our results indicate that OsPDI plays a critical role in seed development through its regulatory activity for various proteins.

This study evaluated the applicability of visible-light-driven N- and S-doped titanium dioxide(TiO2) for the control of low-level dimethyl sulfide(DMS) and dimethyl disulfide(DMDS). In addition, a photocatalytic unit(PU)-adsorption hybrid was evaluated in order to examine the removal of DMS and DMDS which exited the PU and a gaseous photocatalytic byproduct(SO2) which was generated during the photocatalytic processes. Fourier-Tranform-Infrared(FTIR) spectrum exhibited different surface characteristics among the three-types of catalysts. For the N- and S-doped TiO2 powders, a shift of the absorbance spectrum towards the visible-light region was observed. The absorption edge for both the N- and S-doped TiO2 was shifted to λ 720 nm. The N-doped TiO2 was superior to the S-doped TiO2 in regards to DMS degradation. Under low input concentration(IC) conditions(0.039 and 0.027 ppm for DMS and DMDS, respectively), the N-doped TiO2 revealed a high DMS removal efficiency(above 95%), but a gradual decreasing removal efficiency under high IC conditions(7.8 and 5.4 ppm for DMS and DMDS, respectively). Although the hybrid system exhibited a superior characteristic to PU alone regarding the removal efficiencies of both DMS and DMDS, this capability decreased during the course of a photocatalytic process under the high IC conditions. The present study identified the generation of sulfate ion on the catalyst surface and sulfur dioxide(maximum concentrations of 0.0019 and 0.0074 ppm for the photocatalytic processes of DMS and DMDS, respectively) in effluent gas of PU. However, this generation of SO2 would be an insignificant addition to indoor air quality levels.