Polymer-dispersed liquid crystal devices with graphene electrodes

Although polymer-dispersed liquid crystal (PDLC) devices have considerable potential application in smart windows, the high material cost of the indium tin oxide (ITO) electrodes conventionally used in these devices hinders their wide usage. In this work, we explore the use of graphene electrodes as a potential substitute for ITO electrodes in PDLC devices. The fabricated PDLC devices with graphene electrodes exhibit higher contrast and faster response than PDLC devices with ITO electrodes fabricated using the same chemical formulation and polymerization process. However, they also exhibit higher operation voltage and haze, which is primarily attributed to the inherently large resistance and inhomogeneity of the large-area graphene sheets initially transferred onto the transparent substrates. PDLC devices with graphene electrodes are robust under standard operating conditions and also have the advantage of flexibility and stretchability, unlike PDLCs with ITO electrodes. © 2015 Optical Society of America.1

Color-tunable stacked organic light-emitting diode with semi-transparent metal electrode

Stacked organic light-emitting diode (OLED) devices with two terminals have been fabricated by successive application of solution coating and vacuum deposition. We seamlessly engineered the two processing steps by optimizing the semi-transparent metal electrode and the carrier transport buffer layer, and investigated the electrical and optical properties of the thus-prepared devices. The top and bottom OLEDs can be independently addressed by switching the polarity of the voltage applied to the two terminals. The emission color from the stacked OLED devices is easily tuned between green and blue or red and blue, by adjusting the offset of the alternating current applied to the stacked OLED devices. Thus, a simple approach is presented towards printable and color-tunable organic lighting for the future. © 2016 Optical Society of America.1

Disposable Solid-State pH Sensor Using Nanoporous Platinum and Copolyelectrolytic Junction

A disposable solid-state pH sensor was realized by utilizing two nanoporous Pt (npPt) electrodes and a copolyelectrolytic junction One nanoporous Pt electrode was to measure the pH as an indicating electrode (pH-IE) and the other assembled with copolyelectrolytic junction was to maintain constant open circuit potential (E(oc)) as a solid-state reference electrode (SSRE) The copolyelectrolytic Junction was composed of cationic and anionic polymers immobilized by photo-polymerization of N,N`-methylenebisacrylamide, making buffered electrolytic environment on the SSRE It was expected to make The nanoporous Pt surrounded by a constant pH excellently worked as a solid state reference electrode so as to stabilize the system within 30 s and retain the electrochemical environment regardless of unknown sample solutions Combination between the SSRE and the pH-IE commonly based on nanoporous Pt yielded a complete solid-state pH sensor that requires no internal filling solution The solid state pH sensing chip is simple and easy to fabricate so that it could be practically used for disposable purposes Moreover the solid-state pH sensor successfully functions in calibration-free mode in a variety of buffers and surfactant samplesThis work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2005-2001287), the Ministry of Knowledge Economy in Korea (09MC3310, Programmable Bio-CMOS Field Effect Transistors), the Korea Research Foundation Grant funded by Korea Government (MOEHRD, Basic Research Promotion Fund) (KRF-2005-075-C00021), and the Nano/Bio Science & Technology Program (M10536090001- 05N3609-00110) of the Ministry of Education, Science and Technology (MEST), Republic of Korea.Kim KB, 2010, APPL PHYS LETT, V96, DOI 10.1063/1.3389492SUSAN C, 2010, ANAL CHEM, V82, P878Guth U, 2009, J SOLID STATE ELECTR, V13, P27, DOI 10.1007/s10008-008-0574-7Han JW, 2009, JPN J APPL PHYS, V48, DOI 10.1143/JJAP.48.010205Park S, 2007, CHEM MATER, V19, P3373, DOI 10.1021/cm0710756Han JH, 2007, ELECTROANAL, V19, P786, DOI 10.1002/elan.200603772Kwon NH, 2007, ANALYST, V132, P906, DOI 10.1039/b706905gPark S, 2005, ANAL CHEM, V77, P7695, DOI 10.1021/ac050968jHa J, 2005, ANAL CHIM ACTA, V549, P59, DOI 10.1016/j.aca.2005.06.011Chun HG, 2005, ANAL CHEM, V77, P2490, DOI 10.1021/ac048535oVonau W, 2004, ELECTROCHIM ACTA, V49, P3745, DOI 10.1016/j.electacta.2004.02.048Marzouk SAM, 2003, ANAL CHEM, V75, P1258, DOI 10.1021/ac0261404Lee HJ, 1998, ANAL CHEM, V70, P3377Baur JE, 1998, J ELECTROANAL CHEM, V443, P208Suzuki H, 1998, SENSOR ACTUAT B-CHEM, V46, P104Nolan MA, 1997, ANAL CHEM, V69, P1244, DOI 10.1021/ac961020fShin JH, 1996, ANAL CHEM, V68, P3166

Tool to visualize and evaluate operator proficiency in laser hair-removal treatments

BACKGROUND: The uniform delivery of laser energy is particularly important for safe and effective laser hair removal (LHR) treatment. Although it is necessary to quantitatively assess the spatial distribution of the delivered laser, laser spots are difficult to trace owing to a lack of visual cues. This study proposes a novel preclinic tool to evaluate operator proficiency in LHR treatment and applies this tool to train novice operators and compare two different treatment techniques (sliding versus spot-by-spot). METHODS: A simulation bed is constructed to visualize the irradiated laser spots. Six novice operators are recruited to perform four sessions of simulation while changing the treatment techniques and the presence of feedback (sliding without feedback, sliding with feedback, spot-by-spot without feedback, and spot-by-spot with feedback). Laser distribution maps (LDMs) are reconstructed through a series of images processed from the recorded video for each simulation session. Then, an experienced dermatologist classifies the collected LDMs into three different performance groups, which are quantitatively analyzed in terms of four performance indices. RESULTS: The performance groups are characterized by using a combination of four proposed indices. The best-performing group exhibited the lowest amount of randomness in laser delivery and accurate estimation of mean spot distances. The training was only effective in the sliding treatment technique. After the training, omission errors decreased by 6.32% and better estimation of the mean spot distance of the actual size of the laser-emitting window was achieved. Gels required operators to be trained when the spot-by-spot technique was used, and imposed difficulties in maintaining regular laser delivery when the sliding technique was used. CONCLUSIONS: Because the proposed system is simple and highly affordable, it is expected to benefit many operators in clinics to train and maintain skilled performance in LHR treatment, which will eventually lead to accomplishing a uniform laser delivery for safe and effective LHR treatment

Effect of BRCA mutational status on survival outcome in advanced-stage high-grade serous ovarian cancer

Objective To evaluate impact of germline BRCA mutational status on prognosis in patients with advanced ovarian cancer. Methods A total of 128 patients diagnosed with FIGO stage III-IV high-grade serous ovarian cancer (HGSOC) between 2008 and 2017 and underwent BRCA1/2 gene testing at the time of or within two years from cancer diagnosis were included in this study. We compared patients clinicopathological characteristics and survival outcomes after primary treatment according to germline BRCA mutational status. Treatment-related factors that might affect patients survival outcome were also investigated. Results Germline BRCA1/2 mutations were observed in 51 women (39.8%). There were no differences in age and serum CA-125 levels at the time of HGSOC diagnosis, use of neoadjuvant chemotherapy (NAC), extent of debulking surgery, and overall survival (OS) between the BRCA mutation and wild-type BRCA groups. In contrast, the BRCA mutation group displayed longer progression-free survival (PFS) (median, 22.9 vs. 16.9 months, P = 0.001). Multivariate analyses identified germline BRCA1/2 mutation as an independent favorable prognostic factor for PFS (adjusted HR, 0.502; 95% CI, 0.318–0.795; P = 0.003). In the wild-type BRCA group, patients who received NAC as the primary treatment had shorter PFS compared to those who received primary debulking surgery (PDS) (median, 14.2 vs. 16.9 months, P = 0.003). However, in the BRCA mutation group, PFS did not differ between the NAC and PDS groups (P = 0.082). Conclusions In advanced-stage HGSOC, patients with germline BRCA1/2 mutations have better prognosis with longer PFS than those lacking BRCA mutations. Prognosis after NAC was different according to the BRCA mutational status

Metastasis to the breast from colonic adenocarcinoma

A 63-year-old woman was referred to a breast surgeon with a breast mass discovered incidentally during follow-up study after colon cancer surgery. Invasive adenocarcinoma was revealed on core needle biopsy. Wide excision of the breast including the tumor was performed. On standard histological examination the tumor showed features of moderately differentiated adenocarcinoma. The immunohistochemistry study revealed positive results for cytokeratin (CK)20 and CDX2, but negative for CK7. These are typical characteristics for colon cancer. Considering her history of subtotal colectomy for sigmoid colon cancer, it is presumable that the mass in the breast was of colonic origin, and it was an extremely rare case of metastasis to the breast from primary colorectal neoplasm. Although the instance is rare, clinicians should keep the possibility of breast metastasis from colorectal cancer in mind for early and correct diagnosis