Spatial and temporal effects on SARS-CoV-2 contamination of the healthcare environment

Background: The spatial and temporal extent of SARS-CoV-2 environmental contamination has not been precisely defined. We sought to elucidate contamination of different surface types and how contamination changes over time. Methods: We sampled surfaces longitudinally within COVID-19 patient rooms, performed quantitative RT-PCR for the detection of SARS-CoV-2 RNA, and modeled distance, time, and severity of illness on the probability of detecting SARS-CoV-2 using a mixed-effects binomial model. Results: The probability of detecting SARS-CoV-2 RNA in a patient room did not vary with distance. However, we found that surface type predicted probability of detection, with floors and high-touch surfaces having the highest probability of detection (floors odds ratio (OR) 67.8 (95% CrI 36.3 to 131); high-touch elevated OR 7.39 (95% CrI 4.31 to 13.1)). Increased surface contamination was observed in room where patients required high-flow oxygen, positive airway pressure, or mechanical ventilation (OR 1.6 (95% CrI 1.03 to 2.53)). The probability of elevated surface contamination decayed with prolonged hospitalization, but the probability of floor detection increased with duration of the local pandemic wave. Conclusions: Distance from patient’s bed did not predict SARS-CoV-2 RNA deposition in patient rooms, but surface type, severity of illness, and time from local pandemic wave predicted surface deposition.

The Utilization of Land Surface Temperature Information as an Input for Coastal City

Numerous studies have shown that there is a positive correlation between the increase of urban built-up areas with elevated Surface Urban Heat Island (UHI) temperature. It can be considered that SUHI is a by-product of urbanisation. The study found that SUHI in Makassar City is seasonal dependent. High surface temperature tends to occur in the dry season within the urban centre, expanding to the South-Eastern. Furthermore, by combining land surface temperature and Local Climate Zone (LCZ) classification scheme, 16 out of 17 local climate zones were identified, excluding LCZ 7 (light built) within the observation year. In detailed, the combination of LCZ 3 class (compact low rise) and LCZ 10 class (industrial), occupied more than 80 % of the total built-up category with a surface temperature range of 11° C and 16° C respectively. Furthermore, the result indicates a homogenous surface temperature within LCZ 3 with a lower SD of 1.40° C compared to LCZ 10 of 1.95° C. Also, the study explored the correlation of various urban and non-urban indices using artificial neural network. Based on the model used, the indices showed poor correlation with LCZ 3 but adversely correlates to LCZ 10. A final loss value of 0.222 in LCZ 10 was obtained. In contrast, LCZ 3 resulted in high final loss value of 146.554. The result indicated that there are other variables which should be considered in exploring SUHI correlation within LCZ 3 (compact low rise) in Makassar City. In contrast, LCZ 10 (industrial) correlate positively with three urban indices, consisting of NDBI (43.94), BI (37.79), and NDBal (34.77). In brief, the result indicated that SUHI phenomenon in LCZ 3 was poorly represented by the model, whereas the level of city development can be predicted better using LCZ 10 (industrial) areas.

Paleoceanography and dinoflagellate cyst stratigraphy across the Lower–Middle Pleistocene Subseries (Calabrian–Chibanian Stage) boundary at the Chiba composite section, Japan

A dinoflagellate cyst record from the highly resolved Chiba composite section in Japan has been used to reconstruct sea-surface paleoceanographic changes across the Lower–Middle Pleistocene Subseries (Calabrian–Chibanian Stage) boundary at the global stratotype, constituting the first detailed study of this microfossil group from the Pleistocene of the Japanese Pacific margin. Cold, subarctic water masses from 794.2 ka gave way to warming and rapid retreat of the Subpolar Front at 789.3 ka, ~ 2000 years before the end of Marine Isotope Stage (MIS) 20. Throughout the fully interglacial conditions of MIS 19c, assemblages are consistent with warm sea surface temperatures but also reveal instability and latitudinal shifts in the Kuroshio Extension system. The abrupt dominance of Protoceratium reticulatum cysts between 772.9 and 770.4 ka (MIS 19b) registers the influence of cooler, mixed, nutrient-rich waters of the Kuroshio–Oyashio Interfrontal Zone resulting from a southward shift of the Kuroshio Extension. Its onset at 772.9 ka serves as a local ecostratigraphic marker for the Chibanian Stage Global Boundary Stratotype Section and Point (GSSP) which occurs just 1.15 m (= 1300 years) below it. An interval from 770.1 ka to the top of the examined succession at 765.8 ka (MIS 19a) represents warm, presumably stratified but still nutrient-elevated surface waters, indicating a northward shift of the Kuroshio Extension ~ 5 kyrs after the termination of full interglacial conditions on land.

Upper mantle structure of Mars from InSight seismic data

For 2 years, the InSight lander has been recording seismic data on Mars that are vital to constrain the structure and thermochemical state of the planet. We used observations of direct (P and S) and surface-reflected (PP, PPP, SS, and SSS) body-wave phases from eight low-frequency marsquakes to constrain the interior structure to a depth of 800 kilometers. We found a structure compatible with a low-velocity zone associated with a thermal lithosphere much thicker than on Earth that is possibly related to a weak S-wave shadow zone at teleseismic distances. By combining the seismic constraints with geodynamic models, we predict that, relative to the primitive mantle, the crust is more enriched in heat-producing elements by a factor of 13 to 20. This enrichment is greater than suggested by gamma-ray surface mapping and has a moderate-to-elevated surface heat flow.

Fabrication of Transition-metal (Zn, Mn, Cu)-based MOFs as Efficient Sensor Materials for Detection of H2 Gas by Clad Modified Fiber Optic Gas Sensor Technique

Recent research demonstrate that promising gas sensing materials are called metal-organic structures (MOFs) and their products due to their tunable form, elevated surface area, and extremely porous structure and physisorption towards gases with relatively low temperature.In this report, recent developments in transition-metal (Zn, Mn, Cu)-based MOFs and their derivatives are synthesized as sensing materials. The sensors samples were analyzed by XRD, SEM, TEM, BET and XPS in order to know the textural, structural and electronic state of the samples. Fiber optic clad modified sensors were fabricated and tested gas sensing properties towards H2 gas with various concentrations (0-1000 ppm). Among the three sensing material, Zn doped MOFs sensor showed outstanding selectivity with high sensitivity (115 counts/kpa) towards H2 gas. Moreover, it has shown high response (20 s) and recovery time (27 s) as well as long term stability. The designed sensors may be required to apply to the production of an outstanding sensor for H2 for commercial uses.

A critical review on ultra high molecular weight polyethylene (UHMWPE) for prosthesis and implant functions

Polymer composites benefit joint prostheses and implants in biomaterials due to their high strength, reliability, and elasticity modules. The addition of nanoparticles into the polymer-based matrix has effectively demonstrated up-grading wear resistance and implant strength improvement. Therefore, due to the elevated surface area and immense properties, considerable attention has been paid to research in integrating nanoparticles for a wide variety of functions. The UHMWPE is extensively used to develop prosthesis and orthopedic operations due to exceptional mechanical and biocompatible features. The various research studies revealed the fabrication of bio nanocomposites with the polymer matrix possesses superior biocompatibility and durability. This paper presents a critical review of UHMWPE for the latest advancement in polymeric implants by adding different nanoparticles. Another exciting aspect of the proposed work is the addition of different organic (carbon, polymeric) and inorganic (metallic and metal oxides) nanoparticles to develop bio-nano composites. An effort has been made to highlight the exceptional features of modified UHMWPE by supplementing nanofillers for biomedical functions.

Super-Resolution Mapping of a Chemical Reaction Driven by Plasmonic Near-Fields

Plasmonic nanoparticles have recently emerged as promising photocatalysts for light-driven chemical conversions. The illumination of these particles results in the generation of highly energetic charge carriers, elevated surface temperatures, and enhanced electromagnetic fields around them. Distinguishing between these often-overlapping processes is of paramount importance for the rational design of future plasmonic photocatalysts. However, the study of chemical reactions mediated by plasmonic effects is typically performed at the ensemble level and, therefore, limited by the intrinsic heterogeneity of the catalyst particles. Here, we report an in-situ single particle study of a chemical reaction driven solely by plasmonic near-fields. Using super-resolution fluorescence microscopy, we achieve single turnover temporal resolution and ~30 nm spatial resolution. This sub-particle accuracy permits the construction of a clear correlation between the simulated electric field distribution around individual metal nanoparticles and their super-resolved catalytic activity maps. Our results can easily be extended to systems with more complex electric field distributions, thereby guiding the design of future advanced photoactive materials.