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Clinical testing has been the cornerstone of public health monitoring and infection control efforts in communities throughout the COVID-19 pandemic. With the extant and anticipated reduction of clinical testing as the disease moves into an endemic state, SARS-CoV-2 wastewater surveillance (WWS) is likely to have greater value as an important diagnostic tool to inform public health. As the widespread adoption of WWS is relatively new at the scale employed for COVID-19, interpretation of data, including the relationship to clinical cases, has yet to be standardized. An in-depth analysis of the metrics derived from WWS is required for public health units/agencies to interpret and utilize WWS-acquired data effectively and efficiently. In this study, the SARS-CoV-2 wastewater signal to clinical cases (WC) ratio was investigated across seven different cities in Canada over periods ranging from 8 to 21 months. Significant increases in the WC ratio occurred when clinical testing eligibility was modified to appointment-only testing, identifying a period of insufficient clinical testing in these communities. The WC ratio decreased significantly during the emergence of the Alpha variant of concern (VOC) in a relatively non-immunized community’s wastewater (40-60% allelic proportion), while a more muted decrease in the WC ratio signaled the emergence of the Delta VOC in a relatively well-immunized community’s wastewater (40-60% allelic proportion). Finally, a rapid and significant decrease in the WC ratio signaled the emergence of the Omicron VOC, likely because of the variant’s greater effectiveness at evading immunity, leading to a significant number of new reported clinical cases, even when vaccine-induced community immunity was high. The WC ratio, used as an additional monitoring metric, complements clinical case counts and wastewater signals as individual metrics in its ability to identify important epidemiological occurrences, adding value to WWS as a diagnostic technology during the COVID-19 pandemic and likely for future pandemics.

Wastewater-based surveillance (WBS) has become an effective tool around the globe for indirect monitoring of COVID-19 in communities. Quantities of viral fragments of SARS-CoV-2 in wastewater are related to numbers of clinical cases of COVID-19 reported within the corresponding sewershed. Variants of Concern (VOCs) have been detected in wastewater by use of reverse transcription quantitative polymerase chain reaction (RT-qPCR) or sequencing. A multiplex RT-qPCR assay to detect and estimate the prevalence of multiple VOCs, including Omicron/Alpha, Beta, Gamma, and Delta, in wastewater RNA extracts was developed and validated. The probe-based multiplex assay, named “N200” focuses on amino acids 199-202, a region of the N gene that contains several mutations that are associated with variants of SARS- CoV-2 within a single amplicon. Each of the probes in the N200 assay are specific to the targeted mutations and worked equally well in single- and multi-plex modes. To estimate prevalence of each VOC, the abundance of the targeted mutation was compared with a non- mutated region within the same amplified region. The N200 assay was applied to monitor frequencies of VOCs in wastewater extracts from six sewersheds in Ontario, Canada collected between December 1, 2021, and January 4, 2022. Using the N200 assay, the replacement of the Delta variant along with the introduction and rapid dominance of the Omicron variant were monitored in near real-time, as they occurred nearly simultaneously at all six locations. The N200 assay is robust and efficient for wastewater surveillance can be adopted into VOC monitoring programs or replace more laborious assays currently being used to monitor SARS- CoV-2 and its VOCs.

A 50 kg-scale high solids anaerobic digestor comprising six sequentially-fed leach beds with a leachate recirculation system and an upflow anaerobic sludge blanket reactor was operated at 37°C for 88 weeks. The feedstock contained a constant fibre fraction (a mix of cardboard, boxboard, newsprint, and fine paper) and varying proportions of food waste. Significantly enhanced co-digestion and methane production from the fibres was observed as the proportion of FW was increased. The most abundant 16S rRNA amplicon sequence variant (ASV), classified as Clostridium butyricum, was correlated with the amount of FW in the system and total methane yield. However, methane yield specifically from the fibre fraction was significantly correlated with organisms classified as Candidatus Roizmanbacteria and Spirochaetaceae. These ASVs together with ASVs classified as Anaerovorax and Methanoculleus correlated strongly to other ASVs in the microbial community, suggesting these are vitally important for ecosystem function and methane production. In addition, tracing the fate of microbes derived from incoming food waste helped to diagnose a poor batch of bulking agent.Table of Contents (TOC)/ Abstract Art

Frequent use of persulfates as oxidants, for in situ chemical oxidation and advanced oxidation processes, warrants the need for developing a fast and efficient method for measuring persulfate concentrations in aqueous samples in the lab and on site. Here, we propose a modified method, based on Liang et al.'s (2008) spectrophotometric method, for measuring both peroxydisulfate (PDS) and peroxymonosulfate (PMS) in the aqueous samples. Our method involves a deep 96-well plate, multi-channel pipettes, a small orbital shaker, and a microplate reader; allowing the preparation and analysis of up to 96 samples in one run. Our proposed method shortens the time by 10 folds, consumes only ∼2% of the original reagents, and generates only ∼2% of the liquid waste compared to the Liang et al.'s method, thus, making our method high-throughput, time-efficient, and cost-effective with reduced environmental impact. The presented microplate reader method is validated in terms of linearity, LOD, LOQ, accuracy, precision, robustness, and selectivity. All the parameters satisfied the acceptance criteria, according to ICH guidelines. The linearity of calibration curves was evaluated by performing the F-test. In general, our method has linear ranges from 20 to 42,000 and 5 to 40,960 μM for PDS and PMS, respectively. Accuracy (% recovery) results suggested that the LOD and LOQ based on the standard deviation of y-intercepts of the regression lines were the most reliable. The LOD/LOQ values for PDS and PMS were 14.7/44.1 and 4.6/14.4 μM, respectively. The proposed method was also modified to work with a standard cuvette spectrophotometer and was validated. A comparison with the UHPLC analysis of PDS showed that our microplate reader method performed equivalently or even outperformed the UHPLC method, in the presence of common groundwater constituents and organic contaminants.

Intensive historical and worldwide use of the persistent pesticide technical-grade hexachlorocyclohexane (HCH), composed of the active ingredient γ-HCH (called lindane) along with several other HCH isomers, has led to widespread contamination. We derived four anaerobic enrichment cultures from HCH-contaminated soil capable of sustainably dechlorinating each of α-, β-, γ-, and δ-HCH isomers stoichiometrically and completely to benzene and monochlorobenzene (MCB). For each isomer, the dechlorination rates increased progressively from µM/day to ∼12µM/day over two years. The molar ratio of benzene to MCB produced was a function of the substrate isomer, and ranged from β (0.77±0.15), α (0.55±0.09), γ (0.13±0.02) to δ (0.06±0.02) in accordance with pathway predictions based on prevalence of antiperiplanar geometry. Cultivation with a different HCH isomer resulted in distinct bacterial communities, but similar archaeal communities. Data from 16S rRNA gene amplicon sequencing and quantitative PCR revealed significant increases in the absolute abundance ofPelobacterandDehalobacter, especially in the α-HCH and δ-HCH cultures. This study provides the first direct comparison of shifts in anaerobic microbial communities induced by the dechlorination of distinct HCH isomers. It also uncovers candidate microorganisms responsible for the dechlorination of α-, β-, γ-, and δ-HCH, a key step towards better understanding and monitoring of natural attenuation processes and improving bioremediation technologies for HCH-contaminated sites.

Chlorinated ethanes are environmental pollutants found frequently at many contaminated industrial sites. 1,1,1-Trichloroethane (1,1,1-TCA) can be dechlorinated and detoxified via abiotic transformation or biologically by the action of dechlorinating microorganisms such asDehalobacter(Dhb). At a field site, it is challenging to distinguish abiotic vs biotic mechanisms as both processes share common transformation products. In this study, we evaluated using theDhb16S rRNA gene and specific reductive dehalogenase genes as biomarkers for 1,1,1-TCA and 1,1-dichloroethane (1,1-DCA) dechlorination. We analyzed samples from laboratory groundwater microcosms and from an industrial site where a mixture of granular zero valent iron (ZVI) and guar gum was injected for 1,1,1-TCA remediation. Abiotic and biotic transformation products were monitored and the changes in dechlorinating organisms were tracked using quantitative PCR (qPCR) with primers targeting theDhb16S rRNA gene and two functional genescfrAanddcrAencoding enzymes that dechlorinate 1,1,1-TCA to 1,1-DCA and 1,1-DCA to chloroethane (CA), respectively. The abundance of thecfrA- anddcrA-like genes confirmed that the two dechlorination steps were carried out by two distinctDhbpopulations at the site. Using cell yields established in laboratory microcosms along with measured abundances of theDhb16S rRNA gene in site samples, biotic and abiotic transformation of 1,1,1-TCA at the site was estimated. The biomarkers used in this study proved useful for tracking biodechlorination of 1,1,1-TCA and 1,1-DCA where both abiotic (e.g. with ZVI) and biotic processes co-occur.

Chlorinated ethanes are environmental pollutants found frequently at many contaminated industrial sites. 1,1,1-Trichloroethane (1,1,1-TCA) can be dechlorinated and detoxified via abiotic transformation or biologically by the action of dechlorinating microorganisms such as Dehalobacter (Dhb). At a field site, it is challenging to distinguish abiotic vs. biotic mechanisms as both processes share common transformation products. In this study, we evaluated using the Dhb 16S rRNA gene and specific reductive dehalogenase genes as biomarkers for 1,1,1-TCA and 1,1-dichloroethane (1,1-DCA) dechlorination. We analyzed samples from laboratory groundwater microcosms and from an industrial site where a mixture of granular zero valent iron (ZVI) and guar gum was injected for 1,1,1-TCA remediation. Abiotic and biotic transformation products were monitored and the changes in dechlorinating organisms were tracked using quantitative PCR (qPCR) with primers targeting the Dhb 16S rRNA gene and two functional genes cfrA and dcrA encoding enzymes that dechlorinate 1,1,1-TCA to 1,1-DCA and 1,1-DCA to chloroethane (CA), respectively. The abundance of the cfrA- and dcrA-like genes confirmed that the two dechlorination steps were carried out by two distinct Dhb populations at the site. The biomarkers used in this study proved useful for monitoring different Dhb populations responsible for step-wise dechlorination and tracking biodegradation of 1,1,1-TCA and 1,1-DCA where both abiotic (e.g., with ZVI) and biotic processes co-occur.

By using sidewall electrode technology, both record small functional TiO 2 selection device (1 × 5 nm2) and HfO 2 based RRAM device (1 × 3 nm2) were for the first time successfully demonstrated in this work, improving the understanding of the switching mechanism in an ultra-small, functional resistive random access memory (RRAM) device. The tunneling based low temperature back-end selection devices show high driving current density of > 10 MA/cm2 and selectivity of > 103. The pulse driven cycle endurance of sub-5nm selection device and RRAM device reaches 106 and 103, respectively. Well controlled TiO 2 barrier produced with conformal plasma oxidation exhibits tight uniformity. The 1 × 3 nm2 RRAM device exhibited an excellent performance, featuring a large on/off verified window (>100), and reasonable reliability (stress time > 103 s). Furthermore, the 1 × 3 nm2 RRAM device exhibited distinctive unipolar behavior when a high voltage and rapid switching operation (7 V, 50 ns) were applied. We also study on double oxide layer device and propose a physical mechanism picture to compare with previous study. This technology demonstrates the potential of future atomic-scale memories.

Stackable 3DFETs such as FinFET using hybrid Si/MoS 2 channels were developed using a fully CMOS-compatible process. Adding several molecular layers (3–16 layers) of the transition-metal dichalcogenide (TMD), MoS 2 to Si fin and nanowire resulted in improved (+25%) I on,n of the FinFET and nanowire FET (NWFET). The PFETs also operated effectively and the N/P device V th are low and matched perfectly. The proposed heterogeneous Si/TMD 3DFETs can be useful in future electronics.

A sidewall electrode technology was successfully developed for the first time in this study, improving the understanding of the working mechanism in an ultra small, functional HfO 2 -based resistive random access memory (RRAM) device (100), and reasonable reliability (stress time > 10 3 s, 2 × 10 4 h at 250 °C). Furthermore, the 1 × 3 nm 2 RRAM device exhibited distinctive unipolar behavior when a high voltage and rapid switching operation (7 V, 50 ns) were applied, and a switching mechanism model is proposed.

This study was designed to evaluate whether medical nutrition therapy administered by registered dietitians could lead to a beneficial clinical and cost outcome in men with hypercholesterolemia. Ninety-five subjects participating in a cholesterol-lowering drug study took part in an 8-week nutrition intervention program before initiating treatment with a cholesterol-lowering medication, Patient records were reviewed via a retrospective chart review to determine plasma lipid levels at the beginning and end of the program and the number and length of sessions with a dietitian. Complete information was available for 74 subjects aged 60.8 n+/- 9.8 years (mean +/- SD). Medical nutrition therapy lowered total serum cholesterol levels 13% (P.001), low-density lipoprotein cholesterol (LDL-C) 15% (P.0001), triglyceride 11% (P.05), and high-density lipoprotein-cholesterol (HDL-C) 4% (P.05). Total dietitian intervention time was 144 +/- 21 minutes (range = 120 to 180 minutes) in 2.8 +/- 0.7 sessions (range = 2 to 4) during 6.81 +/- 0.7 weeks of medical nutrition therapy (range = 6 to 8 weeks). Analysis of covariance was conducted to examine whether mean change in LDL-C differed by number of dietitian visits. Results showed a marginal difference between the number of dietitian visits and change in LDL-C (f = 2.6, P.084). However, the magnitude of LDL-C reduction was significantly higher with 4 dietitian visits (180 minutes) than with 2 visits (120 minutes) (21.9% vs 12.1%; P = .027). Lipid drug eligibility was obviated in 34 of 67 (51%) subjects per the National Cholesterol Treatment Program guidelines algorithm. The estimated annualized cost savings from the avoidance of lipid medications was $60,561.68. Therefore, we conclude that 3 or 4 individualized dietitian visits of 50 minutes each over 7 weeks are associated with a significant serum cholesterol reduction and a savings of health care dollars.

The highest reported sensitivity (35%) of DNA sieving by entropic trapping has been achieved with a low operation voltage of 8V, and short time of 6 minutes. Wafer scale fabrication of 3D artificial nano-channel matrices is based on proven NEMS, MEMS, and Through-Si-Via (TSV) semiconductor technologies and offers high potential for application in portable bioelectronic instruments. A mechanism based on entropic trapping is proposed for the observed high DNA sieving sensitivity by 3D artificial nano-channel matrices.

A 3D stackable and bidirectional Threshold Vacuum Switching (TVS) selector using the same WO x material as the RRAM element is reported. It provides the highest reported current density of >108 A/cm2 and the highest selectivity of >105. Stress test at high current density indicates >108 cycle capability for Reset/Set operation. A mechanism based on recombination of oxygen-ions and vacancies is proposed for the observed volatile switching of TVS. Utilizing the threshold characteristics of the TVS selector, a two-step reading waveform offers potential for 3D-stackable and 4F2 cross-point RRAM applications.