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As COVID-19 swept across the globe, increased ventilation and implementation of air cleaning were emphasized by the US CDC and WHO as important strategies to reduce the risk of inhalation exposure to the virus. To assess whether higher ventilation and air cleaning rates lead to lower exposure risk to SARS-CoV-2, 1274 manuscripts published between April 2020 and September 2022 were screened using key words "airborne SARS-CoV-2 or "SARS-CoV-2 aerosol." Ninety-three studies involved air sampling at locations with known sources (hospitals and residences) were selected and associated data were compiled. Two metrics were used to assess exposure risk: SARS-CoV-2 concentration and SARS-CoV-2 detection rate in air samples. Locations were categorized by type (hospital or residence) and proximity to the location housing the isolated/quarantined patient (primary or secondary). The results showed that hospital wards had lower airborne virus concentrations than residential isolation rooms. A negative correlation was found between airborne virus concentrations in primary-occupancy areas and air changes per hour (ACH). In hospital settings, sample positivity rates were significantly reduced in secondary-occupancy areas compared to primary-occupancy areas, but they were similar across sampling locations in residential settings. ACH and sample positivity rates were negatively correlated, though the effect was diminished when ACH values exceeded 8. While limitations associated with diverse sampling protocols exist, data considered by this meta-analysis support the notion that higher ACH may reduce exposure risks to the virus in ambient air. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Cancer survivors have an increased risk of developing subsequent primary tumors. However, the characteristics of first primary cancers (FPCs) with various types of second primary cancers (SPCs) are poorly understood, which hinders screening strategies. We analyzed data from 1,893,258 patients from the Surveillance, Epidemiology, and End Results (SEER) database to characterize and classify of FPC patients with subsequent SPCs at the pan-cancer level. In total, 3% of patients had SPC, with varied incidence rates observed depending on the types of FPC. Their onset patterns of SPC and diversity of SPC varied. Based on the diversity of the high-incidence sites of SPC, we classified FPCs into two categories: FPCs that require whole-body screening and those that need screening of particular body parts. Moreover, according to the different timing of high incidence of SPCs, our system classifies FPCs into two subtypes: FPCs that require long-term monitoring for the occurrence of SPCs and those that require screening at specific time points for SPCs. Furthermore, we identified 11 anatomical sites where over half of FPC types are prone to SPC occurrence at these locations. The risk factors for SPC occurrence in different FPC types and prognostic factors were also elucidated. Overall, we characterize and classify of FPC patients with subsequent SPCs at the pan-cancer level, which can guide the development of distinct screening strategies for each FPC type. [ABSTRACT FROM AUTHOR]

Reducing the number of images in fringe projection profilometry has emerged as a significant research focus. Traditional temporal phase unwrapping algorithms typically require an additional set of coding fringe or phase shift fringe images to determine the fringe order and facilitate phase unwrapping, in addition to the essential sinusoidal phase shift fringe for calculating the wrapped phase. In order to reduce the required number of fringe images and increase reconstruction speed, this paper proposes a three-dimensional (3D) reconstruction method inspired by spatial phase unwrapping. The proposed method is based on the N-step temporal phase unwrapping algorithm and can solve the wrapped phase and fringe order using only a set of sinusoidal phase shift fringe images. Our method achieves a further reduction in the required number of images without compromising reconstruction accuracy. In the calculation of the absolute phase, our proposed method only requires an N-step standard phase shift sinusoidal fringe image, eliminating the need for additional fringe images to determine the fringe order. Firstly, we employ the standard N-step phase shift algorithm to compute the wrapped phase and apply a mask for background removal. Next, we directly calculate the fringe order using the wrapped phase and mask and solve for the absolute phase based on the connected region labeling theorem. Our method achieves 3D reconstruction using a minimum of three fringe images, while maintaining reconstruction precision comparable to that of the traditional temporal phase unwrapping technique. As no additional fringe image is required to solve the fringe order, our method has the potential to achieve significantly faster reconstruction speed. [ABSTRACT FROM AUTHOR]

Airborne transmission of infectious (viable) SARS-CoV-2 is increasingly accepted as the primary manner by which the virus is spread from person to person. Risk of exposure to airborne virus is higher in enclosed and poorly ventilated spaces. We present a study focused on air sampling within residences occupied by individuals with COVID-19. Air samplers (BioSpot-VIVAS, VIVAS, and BC-251) were positioned in primary- and secondary-occupancy regions in seven homes. Swab samples were collected from high-touch surfaces. Isolation of SARS-CoV-2 was attempted for samples with virus detectable by RT-qPCR. Viable virus was quantified by plaque assay, and complete virus genome sequences were obtained for selected samples from each sampling day. SARS-CoV-2 was detected in 24 of 125 samples (19.2%) by RT-qPCR and isolated from 14 (11.2%) in cell cultures. It was detected in 80.9% (17/21) and cultured from 61.9% (13/21) of air samples collected using water condensation samplers, compared to swab samples which had a RT-qPCR detection rate of 10.5% (4/38) and virus isolation rate of 2.63% (1/38). No statistically significant differences existed in the likelihood of virus detection by RT-qPCR or amount of infectious virus in the air between areas of primary and secondary occupancy within residences. Our work provides information about the presence of SARS-CoV-2 in the air within homes of individuals with COVID-19. Information herein can help individuals make informed decisions about personal exposure risks when sharing indoor spaces with infected individuals isolating at home and further inform health departments and the public about SARS-CoV-2 exposure risks within residences. [ABSTRACT FROM AUTHOR]

In the Upper Ediacaran Dengying Formation of the Sichuan Basin, the presence of abundant, well-preserved microbial carbonates provides a unique opportunity to study Precambrian paleoceanography and microbial carbonate origins. Particularly, the underexplored coated grain dolostones of this formation, characterized by distinct microbially induced fabrics and intragranular dissolution, offer crucial insights for understanding late Ediacaran microbial mineralization and diagenetic sequences. Utilizing selected typical samples, we conducted detailed petrographic and geochemical analyses, revealing a dynamic interplay between microbial processes and sedimentary dynamics. We observe the coexistence of constructive micrite envelopes with microbially induced fabrics such as clots and laminations, highlighting microbial biomineralization's key role in fabric formation. The sedimentary dynamics critically determines the formation processes of the coated grains: low-energy settings foster grain agglomeration and consolidation through clot precipitation between grains, while high-energy settings favor smaller grains binding to microbial mats. Geochemically, micrite envelopes play an essential role in preserving distinct rare earth element (REE) signatures. The weak negative Ce anomalies and positive Eu anomalies within these envelopes point to a suboxic to anoxic depositional environment, directly indicative of the microenvironmental conditions conducive to microbial mineralization processes. Furthermore, our study sheds light on the structural evolution of coated grains with hollow nuclei, proposing that their internal pore formations are influenced by both mineral instability and selective dissolution by meteoric freshwater. These findings not only provide fresh insights into complex diagenetic processes in the Dengying Formation but also substantially advance our understanding of early microbial life and environmental adaptations during the Precambrian. • Revealed the relationship between micrite envelopes and microbially induced fabrics • Proposed a novel formation mechanism for coated grain dolostone in the Dengying Fm. • Investigated the diverse environmental responses of microbiolite fabrics • Established micrite envelopes as dependable records of seawater REE compositions [ABSTRACT FROM AUTHOR]

Microalgae are one of the important sources of organic matter which, if preserved well in sediments, can generate hydrocarbons during burial diagenesis. However, the preservation mode of microalgal organic matter within product aggregates induced by marine microalgae has rarely been examined. Herein, a strain of eukaryotic marine microalgae, Chlorella sp. MASCC-0008, was used to conduct biomineralization experiments in an f/2 medium with a 0.02 mol/L Ca2+ ion concentration and various Mg2+ ion concentrations of 0.05, 0.06, 0.07 and 0.10 mol/L. It was found that the soluble organic matter of the microalgae contains amino acids and fulvic acids which can attract and absorb cations. With an increase in Mg2+ ion concentration in the experimental group with Chlorella sp., the aragonite content of the mineral precipitates increased whereas the calcite content decreased. In contrast, calcite was the sole mineral precipitated in the control experiments with no Chlorella sp.. Due to the porous structure of minerals, their organic matters were preferred to be preserved in aragonite aggregates compared to calcite aggregates. The TOC content of the minerals aggregates is the highest (0.45%) and the hydrocarbon generation potential (S 1 + S 2) of organic matter is the greatest (3.66 mg/g) in those precipitated in the medium with a Mg2+ ion concentration of 0.10 mol/L. Microalgal organic matter has significant hydrocarbon generation potential due to its effective preservation in the product aggregates formed by the microalgal biomineralization. Squalene is the most abundant alkene detected in the pyrolytic products. These results suggest that microalgae can induce precipitation of carbonate minerals, a process that facilitates the sequestration of organic matter within the product aggregates precipitated, thus potentially preserving this microalgal organic matter into the burial diagenetic realm where, if conditions are appropriate, hydrocarbons may be developed. [ABSTRACT FROM AUTHOR]