A Nanocomposite Sol-Gel Film Based on PbS Quantum Dots Embedded into an Amorphous Host Inorganic Matrix.

In this study, a sol-gel film based on lead sulfide (PbS) quantum dots incorporated into a host network was synthesized as a special nanostructured composite material with potential applications in temperature sensor systems. This work dealt with the optical, structural, and morphological properties of a representative PbS quantum dot (QD)-containing thin film belonging to the Al2O3-SiO2-P2O5 system. The film was prepared using the sol-gel method combined with the spin coating technique, starting from a precursor solution containing a suspension of PbS QDs in toluene with a narrow size distribution and coated on a glass substrate in a multilayer process, followed by annealing of each deposited layer. The size (approximately 10 nm) of the lead sulfide nanocrystallites was validated by XRD and by the quantum confinement effect based on the band gap value and by TEM results. The photoluminescence peak of 1505 nm was very close to that of the precursor PbS QD solution, which demonstrated that the synthesis route of the film preserved the optical emission characteristic of the PbS QDs. The photoluminescence of the lead sulfide QD-containing film in the near infrared domain demonstrates that this material is a promising candidate for future sensing applications in temperature monitoring.

Experimental Pharmacology for COVID-19 Treatment: A Geoanalytical Bibliometric Analysis.

OBJECTIVE: The objective of this study is to produce a geo-referenced map of the status of R&D in COVID-related studies in the world. METHODS: Spatial mapping of bibliometric data of Cortellis Drug Discovery Intelligence through a spatial bibliometric model with the aid of a GIS (Geographic Information System) called ArcGIS and the software. RESULTS: We show the countries that have the most studies related to COV ID-19 and their degree of collaboration. No drug discovery-related activity was found in South America and Africa. A geo-referenced map of the most active countries in COVID research was constructed as well as conceptual maps of the 11 most representative drugs employed for COVID treatment. CONCLUSION: The georeferenced conceptual maps produced in the present report allow not only to better understand the leading institutions in R&D in COVID-19 related drugs but also to visualize their interactions and research relationships. This could offer, in addition to a coherent, organized multinational effort, the possibility of searching for other drugs that have been employed for other diseases and that, in terms of their conceptual relations, could represent some possibilities for treating the coronavirus SARS-2.

Opioids for pain treatment of cancer: A knowledge maturity mapping.

The conceptual structure of opioids, based on the bibliometric analysis of 4,935 articles of the Web of Science using the following indices: Science Citation Index Expanded (SCI-EXPANDED), Social Sciences Citation Index (SSCI), Conference Proceedings Citation Index-Science (CPCI-S), Conference Proceedings Citation Index- Social Science and Humanities (CPCI-SSH), Book Citation Index-Science (BKCI-S), Book Citation Index-Social Sciences and Humanities (BKCI-SSH) and Emerging Sources Citation Index (ESCI), was constructed. We analyzed the available articles with the words "Opioids" and "Cancer." We show the evolution and the state of the art in countries where these treatments are implemented. The results were processed identifying the most cited articles to extract the main connections and frequencies of keywords, authors, journals, countries, institutions, and their tendencies and their connection and degree of collaboration. The temporal tendencies, the word cloud, the keyword network, the evolution of words, author's production, and the scientific production by country are analyzed in terms of the increasing frequency in which opioids are employed to treat both cancerous and non-cancerous pain.

Nanostructured PbS-Doped Inorganic Film Synthesized by Sol-Gel Route.

IV-VI semiconductor quantum dots embedded into an inorganic matrix represent nanostructured composite materials with potential application in temperature sensor systems. This study explores the optical, structural, and morphological properties of a novel PbS quantum dots (QDs)-doped inorganic thin film belonging to the Al2O3-SiO2-P2O5 system. The film was synthesized by the sol-gel method, spin coating technique, starting from a precursor solution deposited on a glass substrate in a multilayer process, followed by drying of each deposited layer. Crystalline PbS QDs embedded in the inorganic vitreous host matrix formed a nanocomposite material. Specific investigations such as X-ray diffraction (XRD), optical absorbance in the ultraviolet (UV)-visible (Vis)-near infrared (NIR) domain, NIR luminescence, Raman spectroscopy, scanning electron microscopy-energy dispersive X-ray (SEM-EDX), and atomic force microscopy (AFM) were used to obtain a comprehensive characterization of the deposited film. The dimensions of the PbS nanocrystallite phase were corroborated by XRD, SEM-EDX, and AFM results. The luminescence band from 1400 nm follows the luminescence peak of the precursor solution and that of the dopant solution. The emission of the PbS-doped film in the NIR domain is a premise for potential application in temperature sensing systems.