Prevalence, reasons, and determinants of dietary supplements use among undergraduate female students of health and non-health colleges in a Saudi public university.

PURPOSE: The aim of this study was to gather data from female students studying in both health and non-health colleges at Imam Abdulrahman Bin Faisal University and report the prevalence, reasons, and determinants of dietary supplements use. METHODS: A month-long cross-sectional study was conducted in health and non-health colleges affiliated to Imam Abdulrahman Bin Faisal University in Dammam, Saudi Arabia. Convenient sampling was employed, and the data was gathered through an online survey using the English and Arabic versions of the Dietary Supplement Questionnaire (DSQ). The data was analyzed using SPSS version 23 and Medcalc. The study was approved by an ethics committee. RESULTS: Data from 545 participants was collected. The overall prevalence of dietary supplement use was 32.7% (95% CI: 29.06%- 36.51%). The prevalence was 29.77% (95% CI: 25.29%- 34.56%) among students at all health colleges combined and, it was 37.50% (95% CI: 31.36%- 43.96%) among students at all non-health colleges. Most students used a brand product, spent a monthly cost of SAR 286 (USD 76.3) on supplements and agreed that supplements were good for health (N = 392, 71.9%). Students from non-health- colleges agreed that dietary supplements are good for health in greater numbers as compared to non-health college students (p < 0.001). Students aged ≥ 20 years, studying in a non-health college and up to 3rd year of study, were more 2 times more likely to agree that dietary supplements are good for health. CONCLUSION: Supplements were commonly used among female students at this university however, it was quite low as compared to students from other local and regional universities. Prevalence was higher in non-health colleges as compared to health colleges and the most commonly used supplements were brand products and, multivitamins, used for general health and well-being. This highlights the inclination of students towards supplement use.

Three dimensionally-ordered 2D MoS2 vertical layers integrated on flexible substrates with stretch-tunable functionality and improved sensing capability.

The intrinsically anisotropic crystallinity of two-dimensional (2D) transition metal dichalcogenide (2D TMD) layers enables a variety of intriguing material properties which strongly depend on the physical orientation of constituent 2D layers. For instance, 2D TMDs with vertically-aligned layers exhibit numerous dangling bonds on their 2D layer edge sites predominantly exposed on the surface, projecting significantly improved physical and/or chemical adsorption capability compared to their horizontally-oriented 2D layer counterparts. Such property advantages can be further promoted as far as the material can be integrated onto unconventional substrates of tailored geometry/functionality, offering vast opportunities for a wide range of applications which demand enhanced surface area/reactivity and mechanical flexibility. Herein, we report a new form of 2D TMDs, i.e., three-dimensionally ordered 2D molybdenum disulfide (2D MoS2) with vertically-aligned layers integrated on elastomeric substrates and explore their tunable multi-functionalities and technological promise. We grew large-scale (>2 cm2) vertically-aligned 2D MoS2 layers using a three-dimensionally patterned silicon dioxide (SiO2) template and directly transferred/integrated them onto flexible polydimethylsiloxane (PDMS) substrates by taking advantage of the distinguishable water-wettability of 2D MoS2vs. SiO2. The excellent structural integrity of the integrated vertical 2D MoS2 layers was confirmed by extensive spectroscopy/microscopy characterization. In addition, the stretch-driven unique tunability of their optical and surface properties was also examined. Moreover, we applied this material for flexible humidity sensing and identified significantly improved (>10 times) sensitivity over conventionally-designed horizontal 2D MoS2 layers, further confirming their high potential for unconventional flexible technologies.

Centimeter-Scale 2D van der Waals Vertical Heterostructures Integrated on Deformable Substrates Enabled by Gold Sacrificial Layer-Assisted Growth.

Two-dimensional (2D) transition metal dichalcogenides (TMDs) such as molybdenum or tungsten disulfides (MoS2 or WS2) exhibit extremely large in-plane strain limits and unusual optical/electrical properties, offering unprecedented opportunities for flexible electronics/optoelectronics in new form factors. In order for them to be technologically viable building-blocks for such emerging technologies, it is critically demanded to grow/integrate them onto flexible or arbitrary-shaped substrates on a large wafer-scale compatible with the prevailing microelectronics processes. However, conventional approaches to assemble them on such unconventional substrates via mechanical exfoliations or coevaporation chemical growths have been limited to small-area transfers of 2D TMD layers with uncontrolled spatial homogeneity. Moreover, additional processes involving a prolonged exposure to strong chemical etchants have been required for the separation of as-grown 2D layers, which is detrimental to their material properties. Herein, we report a viable strategy to universally combine the centimeter-scale growth of various 2D TMD layers and their direct assemblies on mechanically deformable substrates. By exploring the water-assisted debonding of gold (Au) interfaced with silicon dioxide (SiO2), we demonstrate the direct growth, transfer, and integration of 2D TMD layers and heterostructures such as 2D MoS2 and 2D MoS2/WS2 vertical stacks on centimeter-scale plastic and metal foil substrates. We identify the dual function of the Au layer as a growth substrate as well as a sacrificial layer which facilitates 2D layer transfer. Furthermore, we demonstrate the versatility of this integration approach by fabricating centimeter-scale 2D MoS2/single walled carbon nanotube (SWNT) vertical heterojunctions which exhibit current rectification and photoresponse. This study opens a pathway to explore large-scale 2D TMD van der Waals layers as device building blocks for emerging mechanically deformable electronics/optoelectronics.

Tumor-associated primo vascular system is derived from xenograft, not host.

The primo vascular system (PVS), which is composed of very small primo-vessels (PV) and primo-nodes (PN), has recently emerged as a third component of circulatory system. Here, we report the presence of a tumor derived PVS in murine xenografts of human histiocytic lymphoma (U937) in close proximity to the tumor. Within this system, PNs are small (~500-600 µM diameter) membranous sac-like structures which contain numerous small cells which can be demonstrated by DAPI staining. Hematoxylin and Eosin (H&E) staining of the peri-tumoral PVS shows the presence of loose structures lined by fibroblasts but filled with dense fibers, cells, lacunae and nerve-like structures. The origin and type of cells within the PVS was characterized by immunostaining with antibodies for CD68, CD45 and lysozyme. The results of these studies reveal that the PVS of the xenograft originates from the human U937 tumor cells. qRT-PCR analysis of mRNA isolated from PVS cells reveals a striking predominance of human, rather than mouse, sequences. Of particular interest, human stem cell specific transcription factors were overexpressed, most notably KLF4, an upstream regulator of NANOG which maintains the pluripotent and undifferentiated state of stem cells. These results suggest that the cells present within the PVS are derived from the human xenograft and suggests that the primo-vessels associated with the xenografted tumor may provide a safe haven for a select population of cancer stem cells. Further understanding of the biological properties of these cells may allow the development of new anti-cancer interventions.