Probing the Critical Role of Interfaces for Superior Performance in PbS Quantum Dot/Graphene Nanohybrid Broadband Photodetectors.

Colloidal quantum dots/graphene (QD/Gr) nanohybrids have been studied intensively for photodetection in a broadband spectrum including ultraviolet, visible, near-infrared, and shortwave infrared (UV-vis-NIR-SWIR). Since the optoelectronic process in the QD/Gr nanohybrid relies on the photogenerated charge carrier transfer from QDs to graphene, understanding the role of the QD-QD and QD-Gr interfaces is imperative to the QD/Gr nanohybrid photodetection. Herein, a systematic study is carried out to probe the effect of these interfaces on the noise, photoresponse, and specific detectivity in the UV-vis-NIR-SWIR spectrum. Interestingly, the photoresponse has been found to be negligible without a 3-mercaptopropionic acid (MPA) ligand exchange, moderate with a single ligand exchange after all QD layers are deposited on graphene, and maximum if it is performed after each QD layer deposition up to five layers of total QD thickness of 260-280 nm. Furthermore, exposure of graphene to C-band UV (UVC) for a short period of 4-5 min before QD deposition leads to improved photoresponse via removal of polar molecules at the QD/Gr interface. With the combination of the MPA ligand exchange and UVC exposure, optimal optoelectronic properties can be obtained on the PbS QD/Gr nanohybrids with high specific detectivity up to 2.6 × 1011, 1.5 × 1011, 5 × 1010, and 1.9 × 109 Jones at 400, 550, 1000, and 1700 nm, respectively, making the nanohybrids promising for broadband photodetection.

Metallic and Non-Metallic Plasmonic Nanostructures for LSPR Sensors.

Localized surface plasmonic resonance (LSPR) provides a unique scheme for light management and has been demonstrated across a large variety of metallic nanostructures. More recently, non-metallic nanostructures of two-dimensional atomic materials and heterostructures have emerged as a promising, low-cost alternative in order to generate strong LSPR. In this paper, a review of the recent progress made on non-metallic LSPR nanostructures will be provided in comparison with their metallic counterparts. A few applications in optoelectronics and sensors will be highlighted. In addition, the remaining challenges and future perspectives will be discussed.

Adaptation of a Couple-Based HIV/STI Prevention Intervention for Latino Men Who Have Sex With Men in New York City.

Predominantly Spanish-speaking Latino men who have sex with men (MSM) and their same-sex partners continue to be at high risk for HIV and STIs. Behavioral research has identified how relationship dynamics for male couples are associated with sexual risk behavior. Connect 'n Unite (CNU), an evidence-based HIV/STI prevention intervention originally created for Black MSM and their same-sex partners, was adapted for predominantly Spanish-speaking Latino MSM and their same-sex partners on the assumption that its key elements would be translatable while its efficacy would be retained. A systematic adaptation process utilizing qualitative methods was used, including intervention adaptation sessions with 20 predominantly Spanish-speaking Latino gay couples and 10 health service providers. The process included five steps: (1) engaging community stakeholders, (2) capturing the lived experiences of Latino gay couples, (3) identifying intervention priorities, (4) integrating the original intervention's social cognitive theory into a relationship-oriented, ecological framework for Latino gay couples, and (5) adapting intervention activities and materials. The adapted intervention, which we called Latinos en Pareja or Latinos in a Relationship, incorporates elements that effective HIV prevention interventions share, including: a solid theoretical foundation; emphasis on increasing risk reduction norms, sexual communication skills and social support for protection; and guidance on how to utilize available, culturally and linguistically appropriate services. The systematic adaptation approach used for a couples-based HIV prevention intervention also can be employed by other researchers and community stakeholders to adapt evidence-based interventions that promote wellness, linkage to care, and disease prevention for populations not originally targeted.

Still a hard-to-reach population? Using social media to recruit Latino gay couples for an HIV intervention adaptation study.

BACKGROUND: Online social networking use has increased rapidly among African American and Latino men who have sex with men (MSM), making it important to understand how these technologies can be used to reach, retain, and maintain individuals in care and promote health wellness. In particular, the Internet is increasingly recognized as a platform for health communication and education. However, little is known about how primarily Spanish-speaking populations use and engage with each other through social media platforms. OBJECTIVE: We aimed to recruit eligible couples for a study to adapt "Connect 'n Unite" (an HIV prevention intervention initially created for black gay couples) for Spanish-speaking Latino gay couples living in New York City. METHODS: In order to successfully design and implement an effective social media recruitment campaign to reach Spanish-speaking Latino gay couples for our ongoing "Latinos en Pareja" study, our community stakeholders and research team used McGuire's communication/persuasion matrix. The matrix guided our research, specifically each marketing "channel", targeted "message", and target population or "receiver". We developed a social media recruitment protocol and trained our research staff and stakeholders to conduct social media recruitment. RESULTS: As a result, in just 1 month, we recruited all of our subjects (N=14 couples, that is, N=28 participants) and reached more than 35,658 participants through different channels. One of the major successes of our social media recruitment campaign was to build a strong stakeholder base that became involved early on in all aspects of the research process-from pilot study writing and development to recruitment and retention. In addition, the variety of "messages" used across different social media platforms (including Facebook, the "Latinos en Pareja" study website, Craigslist, and various smartphone applications such as Grindr, SCRUFF, and Jack'd) helped recruit Latino gay couples. We also relied on a wide range of community-based organizations across New York City to promote the study and build in the social media components. CONCLUSIONS: Our findings highlight the importance of incorporating communication technologies into the recruitment and engagement of participants in HIV interventions. Particularly, the success of our social media recruitment strategy with Spanish-speaking Latino MSM shows that this population is not particularly "hard to reach", as it is often characterized within public health literature.

[A couple-based approach: An innovative effort to tackle HIV infection among Latino gay men.] / Estrategia innovadora enfocada en parejas del mismo sexo para disminuir la infección del VIH en hombres Latinos.

The HIV epidemic is a serious and pervasive health issue in the Latino community. While prevention efforts have helped maintain stability in the overall number of infections among Latinos for more than a decade, this population continues to be affected by HIV at high levels. In particular, Predominantly Spanish-speaking Latino men who have sex with men (MSM) are disproportionately impacted by HIV. Several factors contribute to the HIV epidemic among Predominantly Spanish-speaking Latino MSM including substance use; intimate partner violence; the presence of certain STIs; same-sex relationship dynamics; avoidance of seeking testing counseling and treatment out of fear of discrimination and immigration status; and poverty, migration patterns, and language barriers. In particular, epidemiological behavioral research has identified how relationship dynamics in male couples are associated with sexual risk behavior. Consequently, further research is needed to identify and deliver interventions geared toward couple-based risk reduction among men in same-sex relationships. This paper describes the potential significance that innovative couple-based approaches can have on reducing HIV and AIDS cases among Predominantly Spanish-speaking Latino MSM and their same-sex partners.