Difficulties in conducting clinical research among healthcare practitioners in Saudi Arabia: A cross-sectional survey.

BACKGROUND: Research activity represents an important process conducted to address an issue in a precise and systematic manner. Data of this kind regarding the methodological difficulties encountered by healthcare practitioners in conducting clinical research in Saudi Arabia are scarce. This study aims to assess the methodological difficulties encountered by healthcare practitioners in conducting clinical research in Saudi Arabia. MATERIALS AND METHODS: This cross-sectional survey was conducted among healthcare practitioners who conducted or who were involved in research in Saudi Arabia from June 2018 through August 2018. Data were collected through SurveyMonkey, using a modified version of a questionnaire from a previous similar study. RESULTS: Overall, 236 respondents participated in the study, more than half, that is, 131 (55.50%) had conducted research as principal investigators, 41 (17.40%) had never attended a research workshop, and 57 (24.20%) were members of research committees. Respondents identified "formulating the research title" and "cooperation between research partners" as the easiest research steps by 58 (24.58%) for each. "Receiving funds and financial resources to complete the research project" ranked the highest difficult step by 124 (52.54%) of the respondents. Attending >2 clinical research workshops was significantly associated with lower methodological difficulty scores. Specifically, those who attended scored 35.28 ± 12.86, while those who did not scored 42.34 ± 12.64, with a highly statistically significant difference (P = 0.001). CONCLUSION: These findings show that securing funding and finding an available biostatistician contributed greatly to the methodological difficulties of conducting clinical research. The difficulty score decreased significantly with increasing the number of clinical research workshops attended by the researchers.

Effect of Surface Plasmon Coupling to Optical Cavity Modes on the Field Enhancement and Spectral Response of Dimer-Based sensors.

We present a theoretical approach to narrow the plasmon linewidth and enhance the near-field intensity at a plasmonic dimer gap (hot spot) through coupling the electric localized surface plasmon (LSP) resonance of a silver hemispherical dimer with the resonant modes of a Fabry-Perot (FP) cavity. The strong coupling is demonstrated by the large anticrossing in the reflection spectra and a Rabi splitting of 76 meV. Up to 2-fold enhancement increase can be achieved compared to that without using the cavity. Such high field enhancement has potential applications in optics, including sensors and high resolution imaging devices. In addition, the resonance splitting allows for greater flexibility in using the same array at different wavelengths. We then further propose a practical design to realize such a device and include dimers of different shapes and materials.

Design and simulation of reflect-array metasurfaces in the visible regime.

Metasurfaces are new, promising ultrathin materials that can enable many novel optical devices due to their ability to act as a discontinuity interface that introduces an abrupt change in amplitude, phase, and sometimes the polarization of the incident light at the wavelength scale. Therefore they can function as flat optical elements. Here, we investigate the anomalous reflection of light for transverse-magnetic (TM) polarization for normal and oblique incidence in the visible regime. We propose gradient phase gap-surface plasmon metasurfaces that exhibit high conversion efficiency (up to ∼97% of total reflected light) to the anomalous reflection angle for blue, green, and red wavelengths at normal and oblique incidence, and where light polarization is unchanged after the reflection.

Detection of single amino acid mutation in human breast cancer by disordered plasmonic self-similar chain.

Control of the architecture and electromagnetic behavior of nanostructures offers the possibility of designing and fabricating sensors that, owing to their intrinsic behavior, provide solutions to new problems in various fields. We show detection of peptides in multicomponent mixtures derived from human samples for early diagnosis of breast cancer. The architecture of sensors is based on a matrix array where pixels constitute a plasmonic device showing a strong electric field enhancement localized in an area of a few square nanometers. The method allows detection of single point mutations in peptides composing the BRCA1 protein. The sensitivity demonstrated falls in the picomolar (10(-12) M) range. The success of this approach is a result of accurate design and fabrication control. The residual roughness introduced by fabrication was taken into account in optical modeling and was a further contributing factor in plasmon localization, increasing the sensitivity and selectivity of the sensors. This methodology developed for breast cancer detection can be considered a general strategy that is applicable to various pathologies and other chemical analytical cases where complex mixtures have to be resolved in their constitutive components.