Wirelessly Powered Electrowetting-on-Dielectric(EWOD)

Electrowetting-on-dielectric (EWOD) allows us to control wettability of droplets on a solid surface using electrical inputs and has been used in a wide range of applications including microfluidics, optical displays, lenses, and others. To date, however, they all have been powered in wired connections, limiting their further employments in hard-to-reach area particularly for implantable EWOD devices. One way to deal with the presented issue, a wireless EWOD system is studied and developed. Due to compatibility of EWOD with AC (less than 1 kHz), a wireless powering as prompt method is achieved by a magnetic induction which essentially utilizes AC signal. The wireless powering with droplets actuation is verified in both using spool-type coils and planar coils. In the spool-type wireless EWOD study, the induced voltage at the receiver is much higher (~390 V) than typically required EWOD voltages (at least >50 V), which is sufficient to actuate the droplets. For reliable wireless EWOD actuation, the voltage induction has to be higher than the conventional EWOD while the current does not have to be necessarily high. Since the voltage induction is proportional to the transmission frequency, a higher voltage can be obtained by increasing the transmission frequency. However, if the transmission frequency is too high, the actuation of droplets might be limited. For an efficient EWOD actuation even at such a high transmission frequency, the system might need to be incorporated with an external demodulation circuit. This issue is addressed in the planar wireless EWOD system in which the powering devices and EWOD electrodes are integrated by standard photolithography process. To oscillate droplets while in lateral actuation irrespective of the coil type, amplitude modulation (AM) technique is applied to the wirelessly transmitted signal. Droplet oscillations are often introduced in many applications and beneficial to reduce the contact angle hysteresis. Eventually, by employing the compact wireless EWOD system into particle collecting and mini-boat propulsion, the unnecessary and cumbersome wire connections between the device components are significantly reduced, and more convenient and flexible EWOD operation is achieved with less constraint of the space and equipment

Monitoring of multi-frequency polarization of gamma-ray bright AGNs

We started two observing programs with the Korean VLBI Network (KVN) monitoring changes in the flux density and polarization of relativistic jets in gamma-ray bright AGNs simultaneously at 22, 43, 86, 129 GHz. One is a single-dish weekly-observing program in dual polarization with KVN 21-m diameter radio telescopes beginning in 2011 May. The other is a VLBI monthly-observing program with the three-element VLBI network at an angular resolution range of 1.0--9.2 mas beginning in 2012 December. The monitoring observations aim to study correlation of variability in gamma-ray with that in radio flux density and polarization of relativistic jets when they flare up. These observations enable us to study the origin of the gamma-ray flares of AGNs.Comment: 4 pages, 4 figures, Proceedings of the conference "The innermost regions of relativistic jets and their magnetic fields", Granada, Spai

Advances in porous organic polymers for efficient water capture

Desiccant driven dehumidification for maintaining the proper humidity levels and atmospheric water capture with minimum energy penalty are important aspects in heat pumps, refrigeration, gas and liquid purifications, gas sensing, and clean water production for improved human health and comfort. Water adsorption by using nanoporous materials has emerged as a viable alternative to energy‐intensive industrial processes, thus understanding the significance of their porosity, high surface areas, vast pore volumes, chemical and structural features relative to the water adsorption is quite important. In this review article, important features of nanoporous materials are presented, including zeolites, porous carbons, as well as crystalline and amorphous porous organic polymers (POPs) to define the interactions between the water molecules and the polar/non‐polar functional groups on the surface of these nanoporous materials. In particular, focus is placed on the recent developments in POPs in the context of water capture as a result of their remarkable stability towards water and wide range of available synthetic routes and building blocks for their synthesis. We also highlighted recent approaches to increase the water sorption capacity of POPs by modifying their structure, morphology, porosity, and chemical functionality while emphasizing their promising future in this emerging area

Pseudoinvasion in an Adenomatous Polyp of the Colon Mimicking Invasive Colon Cancer

Pseudoinvasion or pseudocarcinomatous invasion in an adenomatous polyp of the colon can be unfamiliar to an endoscopist. Pseudoinvasion in an adenomatous polyp represents prolapse of the adenomatous epithelium into its stalk. In most cases its morphology does not differ from of general adenomatous polyps, but in some cases it can morphologically mimic a malignant polyp with submucosal invasion due to mass-like lesioning of its stalk. This makes it difficult for endoscopists to differentiate pseudoinvasion in an adenoma from an invasive carcinoma by conventional endoscopy; instead, endoscopic ultrasonography can provide useful information for differentiating these conditions. We report on an 82-year-old man who presented with a large pedunculated polyp with a thick stalk in the sigmoid colon, which mimicked a submucosal invasive carcinoma. The patient was diagnosed with pseudoinvasion in an adenomatous polyp after segmental resection of the sigmoid colon

Recent Changes in the Clinicopathologic Features of Korean Men with Prostate Cancer: A Comparison with Western Populations

Purpose : The aim of this study was to evaluate the recent changes in the clinicopathologic features of prostate cancer in Korea and to compare these features with those of Western populations. Materials and methods : We retrospectively reviewed the data of 1582 men undergoing radical prostatectomy for clinically localized prostate cancer between 1995 and 2007 at 10 institutions in Korea for comparison with Western studies. The patients were divided into two groups in order to evaluate the recent clinicopathological changes in prostate cancer: Group 1 had surgery between 1995 and 2003 (n=280) and Group 2 had surgery between 2004 and 2007 (n=1302). The mean follow-up period was 24 months. Results : Group 1 had a higher prostate-specific antigen level than Group 2 (10.0 ng/mL vs. 7.5 ng/mL, respectively; p<0.001) and a lower proportion of biopsy Gleason scores ≤6 (35.0% vs. 48.1%, respectively; p<0.001). The proportion of patients with clinical T1 stage was higher in Group 2 than in Group 1. Group 1 had a lower proportion of organ-confined disease (59.6% vs. 68.6%; p<0.001) and a lower proportion of Gleason scores ≤6 (21.3% vs. 33.0%; p<0.001), compared to Group 2. However, the relatively higher proportion of pathologic Gleason scores ≤6 in Group 2 was still lower than those of Western men, even though the proportion of organ-confined disease reached to that of Western series. Conclusion : Korean men with prostate cancer currently present better clinicopathologic parameters. However, in comparison, Korean men still show relatively worse pathologic Gleason scores than Western men.ope

Generalized Granuloma Annulare in Infancy Following Bacillus Calmette-Guerin Vaccination

Generalized granuloma annulare (GGA) is a rare benign granulomatous dermatosis characterized by disseminated necrobiotic dermal papules. Histologically, it presents as a lymphohistiocytic granuloma associated with varying degrees of connective tissue degeneration. It usually occurs in adults and rarely affects infants. Herein, we report an interesting case of GGA which occurred in a 3 month-old girl in association with Bacillus Calmette-Guerin vaccination

Diagnostic performance of ultrasonography-guided core-needle biopsy according to MRI LI-RADS diagnostic categories

Purpose According to the American Association for the Study of Liver Diseases (AASLD) guidelines, biopsy is a diagnostic option for focal hepatic lesions depending on the Liver Imaging Reporting and Data System (LI-RADS) category. We evaluated the diagnostic performance of ultrasonography-guided core-needle biopsy (CNB) according to LI-RADS categories. Methods A total of 145 High-risk patients for hepatocellular carcinoma (HCC) who underwent magnetic resonance imaging (MRI) followed by CNB for a focal hepatic lesion preoperatively were retrospectively enrolled. Focal hepatic lesions on MRI were evaluated according to LI-RADS version 2018. Pathologic results were categorized into HCC, non-HCC malignancies, and benignity. The categorization was defined as correct when the CNB pathology and surgical pathology reports were identical. Nondiagnostic results were defined as inadequate CNB pathology findings for a specific diagnosis. The proportion of correct categorizations was calculated for each LI-RADS category, excluding nondiagnostic results. Results After excluding 16 nondiagnostic results, 131 lesions were analyzed (45 LR-5, 24 LR-4, 4 LR-3, and 58 LR-M). All LR-5 lesions were HCC, and CNB correctly categorized 97.8% (44/45) of LR-5 lesions. CNB correctly categorized all 24 LR-4 lesions, 16.7% (4/24) of which were non-HCC malignancies. All LR-M lesions were malignant, and 62.1% (36/58) were non-HCC malignancies. CNB correctly categorized 93.1% (54/58) of LR-M lesions, and 12.5% (3/24) of lesions with CNB results of HCC were confirmed as non-HCC malignancies. Conclusion In agreement with AASLD guidelines, CNB could be helpful for LR-4 lesions, but is unnecessary for LR-5 lesions. In LR-M lesions, CNB results of HCC did not exclude non-HCC malignancy

Synthetic lethality by targeting the RUVBL1/2-TTT complex in mTORC1-hyperactive cancer cells

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.Despite considerable efforts, mTOR inhibitors have produced limited success in the clinic. To define the vulnerabilities of mTORC1-addicted cancer cells and to find previously unknown therapeutic targets, we investigated the mechanism of piperlongumine, a small molecule identified in a chemical library screen to specifically target cancer cells with a hyperactive mTORC1 phenotype. Sensitivity to piperlongumine was dependent on its ability to suppress RUVBL1/2-TTT, a complex involved in chromatin remodeling and DNA repair. Cancer cells with high mTORC1 activity are subjected to higher levels of DNA damage stress via c-Myc and displayed an increased dependency on RUVBL1/2 for survival and counteracting genotoxic stress. Examination of clinical cancer tissues also demonstrated that high mTORC1 activity was accompanied by high RUVBL2 expression. Our findings reveal a previously unknown role for RUVBL1/2 in cell survival, where it acts as a functional chaperone to mitigate stress levels induced in the mTORC1-Myc-DNA damage axis.NIH 1RO1CA142805National Research Foundation of Korea (NRF) grant (NRF-2017R1C1B1006072