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1.
JMIR Res Protoc ; 9(12): e20360, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33258793

RESUMO

BACKGROUND: Daily and on-demand pre-exposure prophylaxis (PrEP) has been well demonstrated to effectively prevent HIV acquisition for men who have sex with men (MSM). More than half of the MSM PrEP users in Taiwan prefer on-demand PrEP; however, on-demand PrEP involves a complicated dosing regimen because it requires precoital and postcoital dosing and sex events are hard to anticipate. Although there are a growing number of mobile apps designed to improve access to HIV prevention services and HIV medication adherence, few mobile apps focus on adherence to PrEP or are designed to accommodate a complicated, on-demand PrEP dosing schedule. OBJECTIVE: The aim of this project is to evaluate the usability of a newly developed mobile app (UPrEPU) to assist MSM PrEP users to self-monitor their adherence to either daily or on-demand PrEP using a user-centered scheme. METHODS: This research will be conducted in 2 phases: app development and usability study. In the app development phase, we will first conduct formative research with end users and stakeholders through in-depth interviews; the results will provide PrEP users' and PrEP navigators' personas as material used in the app conceptualization stage. PrEP navigators are individuals in the health care system that help HIV-negative individuals who need assistance in accessing PrEP care. A low-fidelity prototype of the app feature will be formatted by applying a participatory design approach to engage PrEP users, designers, and app developers in the design process of the app. Then, a high-fidelity prototype of the app will be developed for the usability study and refined iteratively by the multidisciplinary team and new internal testers. Internal testers include the research team consisting of experts in public health, infectious disease, and industrial design and a close network of the research team that is taking PrEP. In the usability study phase, we will enroll 70 MSM PrEP users and follow them up for 4 months. Usability, feasibility, and effectiveness of adherence monitoring will be evaluated. RESULTS: Refinement of the UPrEPU app is currently ongoing. The usability study commenced in May 2020. CONCLUSIONS: The UPrEPU app is one of the first apps designed to help MSM PrEP users to self-manage their PrEP schedule better regardless of dosing modes. With a design-thinking approach and adapting to the cultural context in Taiwan's MSM population, this novel app will have substantial potential to be acceptable and feasible and contribute to the reduction of new HIV infections. TRIAL REGISTRATION: ClinicalTrials.gov NCT04248790; https://clinicaltrials.gov/ct2/show/NCT04248790. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/20360.

2.
J Phys Chem B ; 119(24): 7480-90, 2015 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-25599406

RESUMO

The density functional theory (DFT) with commonly used functionals is known to be incorrect for charge-transfer problems. With long-range-corrected (LC) density functionals, the asymptotic exchange potential is gradually switched to the Hartree-Fock exchange at a long range, and the prediction for charge-transfer states is greatly improved. In this work, we test LC-DFT's performance on charge-transfer couplings. The range-separation parameter can be tuned nonempirically for properties of a generalized DFT. We propose to minimize the difference of highest-occupied Kohn-Sham orbital energy and the ionization potential (for hole transfer) or the lowest-unoccupied orbital energy and the electron affinity (for electron transfer). For photoinduced charge transfer, the minimum in the sum of such differences for the donor and the acceptor is proposed. With the range-separation parameters optimized, we found that ET couplings derived from the LC-DFT are close to those derived from coupled cluster with singles and doubles. When compared with experimentally derived Mulliken-Hush couplings, LC-DFT couplings are greatly improved as well. We also found that the couplings from BNL and LC-BLYP functionals are generally better than those from LC-ωPBE and LC-ωPBE0. LC-DFT is suitable for calculating ET coupling, especially with this nonempirical approach for the range-separation parameter.

3.
J Org Chem ; 77(11): 4924-31, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22537513

RESUMO

The synthesis and full characterization of new derivatives of indolo[3,2-b]carbazole with differently substituted phenyl groups at nitrogen atoms is reported. Comparative study on their thermal, optical electrochemical, and photoelectrical properties is presented. The synthesized compounds are electrochemically stable. Their highest occupied molecular orbital energy values range from -5.14 to -5.07 eV. The electron photoemission spectra of the films of synthesized materials revealed the ionization potentials of 5.31-5.47 eV. Hole drift mobility of the amorphous film of 5,11-bis(3-methoxyphenyl)-6-pentyl-5,11-dihydroindolo[3,2-b]carbazole exceed 10(-3) cm(2)/V·s at high electric fields, as it was established by xerographic time-of-flight technique. In contrast to diphenylamino substituted derivatives of carbazole, no effect of the position of methoxy groups on the photoelectrical properties was observed for the synthesized methoxyphenyl-substituted derivatives of indolo[3,2-b]carbazole. The indolo[3,2-b]carbazole core has a larger resonance structure that includes 3 phenyl rings, and thus the energy gap of the HOMO and LUMO π orbitals is lower as compared to that of carbazoles. With a larger energy difference between the phenyl substituents and the core moiety, the indolo[3,2-b]carbazole derivatives studied all have a weaker coupling between the phenyl group and a much weaker dependence of the molecular properties on the position of substituents on the phenyl groups as compared to those observed in substituted carbazoles.

4.
J Biomed Sci ; 18: 12, 2011 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-21299869

RESUMO

BACKGROUND: The Cdc42-interacting protein-4, Trip10 (also known as CIP4), is a multi-domain adaptor protein involved in diverse cellular processes, which functions in a tissue-specific and cell lineage-specific manner. We previously found that Trip10 is highly expressed in estrogen receptor-expressing (ER+) breast cancer cells. Estrogen receptor depletion reduced Trip10 expression by progressively increasing DNA methylation. We hypothesized that Trip10 functions as a tumor suppressor and may be involved in the malignancy of ER-negative (ER-) breast cancer. To test this hypothesis and evaluate whether Trip10 is epigenetically regulated by DNA methylation in other cancers, we evaluated DNA methylation of Trip10 in liver cancer, brain tumor, ovarian cancer, and breast cancer. METHODS: We applied methylation-specific polymerase chain reaction and bisulfite sequencing to determine the DNA methylation of Trip10 in various cancer cell lines and tumor specimens. We also overexpressed Trip10 to observe its effect on colony formation and in vivo tumorigenesis. RESULTS: We found that Trip10 is hypermethylated in brain tumor and breast cancer, but hypomethylated in liver cancer. Overexpressed Trip10 was associated with endogenous Cdc42 and huntingtin in IMR-32 brain tumor cells and CP70 ovarian cancer cells. However, overexpression of Trip10 promoted colony formation in IMR-32 cells and tumorigenesis in mice inoculated with IMR-32 cells, whereas overexpressed Trip10 substantially suppressed colony formation in CP70 cells and tumorigenesis in mice inoculated with CP70 cells. CONCLUSIONS: Trip10 regulates cancer cell growth and death in a cancer type-specific manner. Differential DNA methylation of Trip10 can either promote cell survival or cell death in a cell type-dependent manner.


Assuntos
Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Proteínas Associadas aos Microtúbulos/biossíntese , Proteínas de Neoplasias/biossíntese , Neoplasias/metabolismo , Animais , Morte Celular/genética , Sobrevivência Celular , Metilação de DNA/genética , Feminino , Células Hep G2 , Humanos , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Antígenos de Histocompatibilidade Menor , Proteínas de Neoplasias/genética , Neoplasias/patologia
5.
Biochem Biophys Res Commun ; 400(3): 305-12, 2010 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-20727853

RESUMO

Epigenetic regulation of gene expression by DNA methylation and histone modification controls cell fate during development and homeostasis in adulthood. Aberrant epigenetic modifications may lead to abnormal development, even diseases. We have found that Trip10 (thyroid hormone receptor interactor 10), an adaptor protein involved in diverse functions, is epigenetically regulated during lineage-specific induction of human bone marrow-derived mesenchymal stem cells (MSCs). To determine whether DNA methylation-induced gene silencing is sufficient to restrict cell fate changes, we applied an invitro method to specifically methylate the promoter of Trip10. Our hypothesis was that the methylation status of the Trip10 promoter in MSCs alters the differentiation preference of MSCs. Transfection of in vitro-methylated Trip10 promoter DNA into MSCs resulted in progressive accumulation of cytosine methylation at the endogenous Trip10 promoter, reduced Trip10 expression, and accelerated MSC-to-neuron and MSC-to-osteocyte differentiation. A two-component EGFP reporter gene system was established to confirm the level of transcriptional silencing and visualize the targeted DNA methylation. EGFP expression induced in the reporter system by targeted Trip10 methylation was reversed by adding 5-aza-2'-deoxycytidine, a DNA methyltransferase inhibitor, confirming that the suppressed Trip10 expression and disrupted MSC differentiation resulted from the in vitro-introduced methylations in the Trip10 promoter. With this targeted DNA methylation and reporter system, we are able to monitor the progression of locus-specific DNA methylation in vivo and correlate such changes with potential functional changes. Using this approach, we have established a new role for Trip10, showing that the level of Trip10 expression is associated with the maintenance and differentiation of MSCs.


Assuntos
Linhagem da Célula/genética , Metilação de DNA , Inativação Gênica , Células-Tronco Mesenquimais/fisiologia , Proteínas Associadas aos Microtúbulos/fisiologia , Animais , Diferenciação Celular/genética , Linhagem Celular Tumoral , Células Cultivadas , Humanos , Células-Tronco Mesenquimais/citologia , Proteínas Associadas aos Microtúbulos/genética , Antígenos de Histocompatibilidade Menor , Regiões Promotoras Genéticas , Ratos
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