Programmable Aggregation of Artificial Cells with DNA Signals.

Cell aggregation is a complex behavior that is closely related to the viability, differentiation, and migration of cells. An effort to create synthetic analogs could lead to considerable advances in cell physiology and biophysics. Rendering and modulating such a dynamic artificial cell system require mechanisms for receiving, transducing, and transmitting intercellular signals, yet effective tools are limited at present. Here we construct synthetic cells from engineered lipids and show their programmable aggregation behaviors using DNA oligonucleotides as signaling molecules. The artificial cells have transmembrane channels made of DNA origami that are used to recognize and process intercellular signals. We demonstrate that multiple small vesicles aggregate onto a giant vesicle after a transduction of external DNA signals by an intracellular enzyme and that the small vesicles dissociate when receiving "release" signals. This work provides new possibilities for building synthetic protocells capable of chemical communication and coordination.

Perovskites fabricated on textured silicon surfaces for tandem solar cells.

The silicon surface texture significantly affects the current density and efficiency of perovskite/silicon tandem solar cells. However, only a few studies have explored fabricating perovskite on textured silicon and the effect of texture on perovskite films because of the limitations of solution processes. Here we produce conformal perovskite on textured silicon with a dry two-step conversion process that incorporates lead oxide sputtering and direct contact with methyl ammonium iodide. To separately analyze the influence of each texture structure on perovskite films, patterned texture, high-resolution photoluminescence (µ-PL), and light beam-induced current (µ-LBIC), 3D mapping is used. This work elucidates conformal perovskite on textured surfaces and shows the effects of textured silicon on the perovskite layers with high-resolution 3D mapping. This approach can potentially be applied to any type of layer on any type of substrate.

Correction: Role of polysilicon in poly-Si/SiO x passivating contacts for high-efficiency silicon solar cells.

[This corrects the article DOI: 10.1039/C9RA03560E.].

Role of polysilicon in poly-Si/SiO x passivating contacts for high-efficiency silicon solar cells.

In this study, we focused on understanding the roles of a polysilicon (poly-Si) layer in poly-Si/SiO x /c-Si passivating contacts. Passivating contact formation conditions were varied by changing the doping method, annealing temperature and time, polysilicon layer thickness, and polysilicon doping concentration. Our observations indicated that the roles of polysilicon are contact, in-diffusion barrier action, field effect, gettering, and light absorption. Based on the observations, a iV OC of 741 mV was obtained. Finally, to increase J SC with high V OC, the polysilicon was etched after hydrogenation to reduce light absorption with high passivation quality. iV OC was not affected by etching; moreover, by etching the polysilicon from 300 nm to 60 nm, the cell efficiency increased from 20.48% to 20.59% with increasing J SC, constant V OC, and fill factor.

Determination of donepezil in human plasma using ultra performance liquid chromatography-tandem mass spectrometry.

An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantification of donepezil in human plasma. Donepezil and donepezil-D4 were extracted from human plasma by liquid-liquid extraction using a mixture of hexane and ethyl acetate (70:30 v/v). The extracted samples were analyzed using a Thermo Hypersil Gold C18 column with 5% acetic acid in 20 mM ammonium acetate buffer (pH 3.3) and 100% acetonitrile as a mobile phase with the 60:40 (v:v) isocratic method, at a flow rate of 0.3 mL/min. The injection volume was 3 µL, and the total run time was 3 min. Inter- and intra-batch accuracies ranged from 98.0% to 110.0%, and the precision was below 8%. The developed method was successfully applied to the quantification of donepezil in human plasma. The mean (standard deviation) maximum concentration and the median (range) time to maximum concentration were 8.6 (2.0) ng/mL and 2.0 h (1.0~5.0 h), respectively, in healthy Koreans after oral administration of 5 mg donepezil.

Atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesion triage in Korean women: Revisiting the 2012 American Society of Colposcopy and Cervical Pathology screening guidelines.

OBJECTIVE: To determine whether triage for atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL) from the updated American Society for Colposcopy and Cervical Pathology cervical cancer screening guidelines is applicable in Korean women. METHODS: We investigated women with ASC-US or LSIL including referred from local hospitals visited for cervical cancer screening at Korea University Guro Hospital from February 2004 to December 2014. Detailed information on the results of Papanicolaou (Pap) smears, human papillomavirus (HPV) DNA tests, and cervical biopsies were collected through chart review. Cervical biopsy results were compared in eligible women according to individual Pap smear findings and HPV DNA status. RESULTS: Of 216,723 possible cases, 3,196 were included. There were 212 (6.6%) women with ASC-US and 500 (15.6%) with LSIL. The risk of ≥cervical intraepithelial neoplasia (CIN) 2 was significantly higher in women who were ASC-US/HPV+ than ASC-US/HPV- and LSIL/HPV+ than LSIL/HPV- (93.3% vs. 6.7% and 96.7% vs. 3.3%, P<0.001 and P<0.001, respectively). The risk of ≥CIN 3 was also significantly higher in women who were ASC-US/HPV+ than ASC-US/HPV- and LSIL/HPV+ than LSIL/HPV- (97.0% vs. 3.0% and 93.0% vs. 7.0%, P<0.001 and P<0.001, respectively). Age-stratified analysis revealed that more CIN 2 or CIN 3 was diagnosed in women aged 30 to 70 with ASC-US or LSIL when HPV DNA was present. CONCLUSION: Observation with Pap and HPV DNA tests rather than immediate colposcopy is a reasonable strategy for ASC-US or LSIL when the HPV DNA test is negative, especially in women aged 30 to 70. Reflection of these results should be considered in future Korean screening guidelines.

Fully Validated Ultra-performance Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of Fimasartan in Human Plasma.

Fimasartan is a novel angiotensin II receptor blocker with strong anti-hypertensive activity. In this study, a more rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to determine fimasartan in human plasma was developed and fully validated. The quantification of analytes was conducted by MS/MS in a multiple reaction monitoring mode at m/z 502.2 → 207.1 for fimasartan and m/z 526.3 → 207.1 for the internal standard (IS, BR-A-563). The method showed a linear response from 3 to 1000 ng/mL (r > 0.9950). The intra- and inter-day accuracy values were 86.9 - 98.2 and 93.3 - 100.1%, respectively. The intra- and inter-day precision values were 2.0 - 3.1 and 0.8 - 8.0%, respectively. This UPLC-MS/MS method was validated for specificity, linearity, precision, accuracy, recovery, system suitability, and stability, and was found to be acceptable for bioanalytical applications. Finally, this fully validated method was successfully applied to a pharmacokinetic study of fimasartan in healthy volunteers following oral administration.

Unusual presentation of Ewing sarcoma in the adrenal gland: a secondary malignancy from a survivor of Burkitt lymphoma.

The occurrence of Ewing sarcoma as a secondary malignancy is an extremely rare event in long-term cancer survivors. In addition, the occurrence of Ewing sarcoma in the adrenal gland is highly unusual. In this case report, we treated a 20-year-old male patient with cyclophosphamide, doxorubicin, vincristine, dexamethasone, and methotrexate and cytarabine chemotherapy following a diagnosis of Stage IV Burkitt lymphoma. Following complete remission, he had been maintained for 2 years without evidence of disease. However, a regular follow-up computed tomography scan found a left adrenal gland mass and a biopsy revealed positive membrane-localized mic-2 expression (CD99) and the presence of the translocation of the EWSR1 gene. To our knowledge, this is the first case report of Ewing sarcoma occurring in the adrenal gland of a patient who was treated with cyclophosphamide, doxorubicin, vincristine, dexamethasone/methotrexate and cytarabine chemotherapy for Burkitt lymphoma.