Controlled synthesis of ultrathin MoS2 nanoflowers for highly enhanced NO2 sensing at room temperature

Fabrication of a high-performance room-temperature (RT) gas sensor is important for the future integration of sensors into smart, portable and Internet-of-Things (IoT)-based devices. Herein, we developed a NO₂ gas sensor based on ultrathin MoS₂ nanoflowers with high sensitivity at RT. The MoS₂ flower-like nanostructures were synthesised via a simple hydrothermal method with different growth times of 24, 36, 48, and 60 h. The synthesised MoS₂ nanoflowers were subsequently characterised by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy and transmission electron microscopy. The petal-like nanosheets in pure MoS₂ agglomerated to form a flower-like structure with Raman vibrational modes at 378 and 403 cm⁻¹ and crystallisation in the hexagonal phase. The specific surface areas of the MoS₂ grown at different times were measured by using the Brunauer–Emmett–Teller method. The largest specific surface area of 56.57 m² g⁻¹ was obtained for the MoS₂ nanoflowers grown for 48 h. This sample also possessed the smallest activation energy of 0.08 eV. The gas-sensing characteristics of sensors based on the synthesised MoS₂ nanostructures were investigated using oxidising and reducing gases, such as NO₂, SO₂, H₂, CH₄, CO and NH₃, at different concentrations and at working temperatures ranging from RT to 150 °C. The sensor based on the MoS₂ nanoflowers grown for 48 h showed a high gas response of 67.4% and high selectivity to 10 ppm NO₂ at RT. This finding can be ascribed to the synergistic effects of largest specific surface area, smallest crystallite size and lowest activation energy of the MoS₂-48 h sample among the samples. The sensors also exhibited a relative humidity-independent sensing characteristic at RT and a low detection limit of 84 ppb, thereby allowing their practical application to portable IoT-based devices.

Controlled synthesis of ultrathin MoS₂ nanoflowers is crucial to develop a high-performance room-temperature NO₂ gas sensor for the future integration of sensors into smart, portable and Internet-of-Things (IoT)-based devices.     

Genetic characteristics of 23 Y-chromosomal STRs in the Kinh population in Northern Vietnam

We collected and analysed the genetic characteristics of 23 Y-STR data of 200 unrelated Kinh individuals living in the North of Vietnam. Haplotype frequencies and forensic parameters were calculated, showing high discrimination value. Population comparison analysis was performed to determine the genetic relationship with neighbouring ethnicities, in particular with Thai and Han populations.

     

Navigating Uncertainty in the Management of Incidental Findings

The lack of prospective outcomes studies for many types of incidental findings limits our understanding of both their natural history and the potential efficacy of treatment. To support decision making for the management of incidental findings, major sources of uncertainty in management pathways can be mapped and analyzed using mathematical models. This process yields important insights into how uncertainty influences the best treatment decision. Here, we consider a classification scheme, grounded in decision science, which exposes various levels and types of uncertainty in the management of incidental findings and addresses (1) disease-related risks, which are considered in context of a patient’s competing causes of mortality; (2) potential degrees of intervention; (3) strength of evidence; and (4) patients’ treatment-related preferences. Herein we describe how categorizing uncertainty by the sources, issues, and locus can build a framework from which to improve the management of incidental findings. Accurate and comprehensive handling of uncertainty will improve the quality of related decision making and will help guide future research priorities.     

WHO's Service Availability and Readiness Assessment of primary health care services of commune health centers in a rural district of Northern Vietnam

The objective of this study was to assess the availability and readiness of the primary health care (PHC) services of commune health centers (CHCs) in Quoc Oai, a rural district of Northern Vietnam based on the World Health Organization's Service Availability and Readiness Assessment (SARA) tool. The study was done in 2 steps. First, the heads of the 21 CHCs of Quoc Oai district were interviewed using SARA, a quantitative survey, and the responses were then validated by direct observations of each facility. The results showed that although the average number of health staffs in each CHC met the national standards (at least 5 staffs per CHC), its allocation within each CHC was not properly met because some CHCs had only 2 health staffs. Several health equipment and facilities were not fully available in many CHCs, and although the majority of the PHC services were available at the CHCs, their readiness remained limited. Several significant correlates between the availability of health care workers and the availability of the facilities and the PHC services were observed, suggesting that they depend upon and affect one another in the health system. Using the SARA‐based inventory, the study helps health managers and policy makers to prioritize efforts and allocate resources more appropriately. To be effective, attention should be given to how to make facilities, services, and human resources for health ready for PHC activities—more investment and support from the system (from higher to lower level) and the government.