Comparison of an ID NOW COVID-19 Assay Used at the Point of Care to Laboratory-Based Nucleic Acid Amplification Tests.

The emergence of a novel coronavirus, namely, SARS-CoV-2, necessitated the use of rapid, accurate diagnostics to quickly diagnose COVID-19. This need has increased with the emergence of new variants and continued waves of COVID-19 cases. The ID NOW COVID-19 assay is a rapid nucleic acid amplification test (NAAT) that is used by hospitals, urgent care facilities, medical clinics, and public health laboratories for rapid molecular SARS-CoV-2 testing at the point of care. The District of Columbia Department of Forensic Sciences Public Health Laboratory Division (DC DFS PHL) implemented ID NOW COVID-19 testing in nontraditional laboratory settings, including a mobile testing unit, health clinic, and emergency department, to assist with rapid identification and isolation for populations at high risk of SARS-CoV-2 transmission in the District of Columbia. The DC DFS PHL provided these nontraditional laboratories with safety risk assessment, assay training, competency assessment, and quality control monitoring as parts of a comprehensive quality management system (QMS). We assessed the accuracy of the ID NOW COVID-19 assay when operated in the context of these trainings and systems. This was done by comparing results from 9,518 paired tests, and strong agreement (κ = 0.88, OPA = 98.3%) was found between the ID NOW COVID-19 assay and laboratory-based NAATs. These findings indicate that the ID NOW COVID-19 assay can be used to detect SARS-CoV-2 in nontraditional laboratory settings when used within the context of a comprehensive QMS.

Computational and experimental studies of the wide bandgap semiconductors NH4TiOF3 and (NH4)2TiOF4.

As the topotactic synthetic precursor of the ubiquitous functional semiconductor anatase TiO2, ammonium fluoroxotitanates, such as NH4TiOF3 and (NH4)2TiOF4, have received lots of research interest as synthetic precursors. However, few of the existing studies focus on their properties and possible applications on their own. To fill this gap, both NH4TiOF3 and (NH4)2TiOF4 were studied in this work experimentally by material characterization and computationally via DFT calculations. Electronic structures of both materials from experimental and computational perspectives were mutually supportive. Based on these, immobilised NH4TiOF3 was preliminarily tested as a UV photocatalyst for dye degradation. Reasonable photocatalytic activities were observed.

High Daytime Temperature Responsive MicroRNA Profiles in Developing Grains of Rice Varieties with Contrasting Chalkiness.

High temperature impairs starch biosynthesis in developing rice grains and thereby increases chalkiness, affecting the grain quality. Genome encoded microRNAs (miRNAs) fine-tune target transcript abundances in a spatio-temporal specific manner, and this mode of gene regulation is critical for a myriad of developmental processes as well as stress responses. However, the role of miRNAs in maintaining rice grain quality/chalkiness during high daytime temperature (HDT) stress is relatively unknown. To uncover the role of miRNAs in this process, we used five contrasting rice genotypes (low chalky lines Cyp, Ben, and KB and high chalky lines LaGrue and NB) and compared the miRNA profiles in the R6 stage caryopsis samples from plants subjected to prolonged HDT (from the onset of fertilization through R6 stage of caryopsis development). Our small RNA analysis has identified approximately 744 miRNAs that can be grouped into 291 families. Of these, 186 miRNAs belonging to 103 families are differentially regulated under HDT. Only two miRNAs, Osa-miR444f and Osa-miR1866-5p, were upregulated in all genotypes, implying that the regulations greatly varied between the genotypes. Furthermore, not even a single miRNA was commonly up/down regulated specifically in the three tolerant genotypes. However, three miRNAs (Osa-miR1866-3p, Osa-miR5150-3p and canH-miR9774a,b-3p) were commonly upregulated and onemiRNA (Osa-miR393b-5p) was commonly downregulated specifically in the sensitive genotypes (LaGrue and NB). These observations suggest that few similarities exist within the low chalky or high chalky genotypes, possibly due to high genetic variation. Among the five genotypes used, Cypress and LaGrue are genetically closely related, but exhibit contrasting chalkiness under HDT, and thus, a comparison between them is most relevant. This comparison revealed a general tendency for Cypress to display miRNA regulations that could decrease chalkiness under HDT compared with LaGrue. This study suggests that miRNAs could play an important role in maintaining grain quality in HDT-stressed rice.

Linking in situ charge accumulation to electronic structure in doped SrTiO3 reveals design principles for hydrogen-evolving photocatalysts.

Recently, high solar-to-hydrogen efficiencies were demonstrated using La and Rh co-doped SrTiO3 (La,Rh:SrTiO3) incorporated into a low-cost and scalable Z-scheme device, known as a photocatalyst sheet. However, the unique properties that enable La,Rh:SrTiO3 to support this impressive performance are not fully understood. Combining in situ spectroelectrochemical measurements with density functional theory and photoelectron spectroscopy produces a depletion model of Rh:SrTiO3 and La,Rh:SrTiO3 photocatalyst sheets. This reveals remarkable properties, such as deep flatband potentials (+2 V versus the reversible hydrogen electrode) and a Rh oxidation state dependent reorganization of the electronic structure, involving the loss of a vacant Rh 4d mid-gap state. This reorganization enables Rh:SrTiO3 to be reduced by co-doping without compromising the p-type character. In situ time-resolved spectroscopies show that the electronic structure reorganization induced by Rh reduction controls the electron lifetime in photocatalyst sheets. In Rh:SrTiO3, enhanced lifetimes can only be obtained at negative applied potentials, where the complete Z-scheme operates inefficiently. La co-doping fixes Rh in the 3+ state, which results in long-lived photogenerated electrons even at very positive potentials (+1 V versus the reversible hydrogen electrode), in which both components of the complete device operate effectively. This understanding of the role of co-dopants provides a new insight into the design principles for water-splitting devices based on bandgap-engineered metal oxides.

A cohort study measuring SARS-CoV-2 seroconversion and serial viral testing in university students.

BACKGROUND: To improve understanding of the antibody response to SARS-CoV-2 infection, we examined seroprevalence, incidence of infection, and seroconversion among a cohort of young adults living on university campuses during the fall of 2020. METHODS: At the beginning (semester start) and end (semester end) of an 11-week period, serum collected from 107 students was tested using the qualitative Abbott Architect SARS-CoV-2 IgG and AdviseDx SARS-CoV-2 IgG II assays. Results were matched to interim weekly surveillance viral testing and symptom data. RESULTS: With the SARS-CoV-2 IgG assay, 15 (14.0%) students were seropositive at semester start; 29 (27.1%) students were seropositive at semester end; 10 (9.3%) were seropositive at both times. With the AdviseDx SARS-CoV-2 IgG II assay, 17 (16.3%) students were seropositive at semester start, 37 (35.6%) were seropositive at semester end, and 16 (15.3%) were seropositive at both times. Overall, 23 students (21.5%) had positive viral tests during the semester. Infection was identified by serial testing in a large majority of individuals who seroconverted using both assays. Those seropositive at semester end more frequently reported symptomatic infections (56.5%) than asymptomatic infections (30.4%). CONCLUSION: Differences between antibody targets were observed, with more declines in antibody index values below the threshold of positivity with the anti-nucleocapsid assay compared to the anti-spike assay. Serology testing, combined with serial viral testing, can detect seroconversions, and help understand the potential correlates of protection provided by antibodies to SARS-CoV-2.

Hollow-core resonator fiber optic gyroscope using nodeless anti-resonant fiber.

Resonator fiber optic gyroscope (RFOG) performance has hitherto been limited by nonlinearity, modal impurity, and backscattering in the sensing fibers. The use of hollow-core fiber (HCF) effectively reduces nonlinearity, but the complex interplay among glass and air-guided modes in conventional HCF technologies can severely exacerbate RFOG instability. By employing high-performance nested anti-resonant nodeless fiber, we demonstrate long-term stability in a hollow-fiber RFOG of 0.05 deg/h, nearing the levels required for civil aircraft navigation. This represents a ${{3}} \times$ improvement over any prior hollow-core RFOG and a factor of ${{500}} \times$ over any prior result at integration times longer than 1 h.

Technologies to address antimicrobial resistance.

Bacterial infections have been traditionally controlled by antibiotics and vaccines, and these approaches have greatly improved health and longevity. However, multiple stakeholders are declaring that the lack of new interventions is putting our ability to prevent and treat bacterial infections at risk. Vaccine and antibiotic approaches still have the potential to address this threat. Innovative vaccine technologies, such as reverse vaccinology, novel adjuvants, and rationally designed bacterial outer membrane vesicles, together with progress in polysaccharide conjugation and antigen design, have the potential to boost the development of vaccines targeting several classes of multidrug-resistant bacteria. Furthermore, new approaches to deliver small-molecule antibacterials into bacteria, such as hijacking active uptake pathways and potentiator approaches, along with a focus on alternative modalities, such as targeting host factors, blocking bacterial virulence factors, monoclonal antibodies, and microbiome interventions, all have potential. Both vaccines and antibacterial approaches are needed to tackle the global challenge of antimicrobial resistance (AMR), and both areas have the underpinning science to address this need. However, a concerted research agenda and rethinking of the value society puts on interventions that save lives, by preventing or treating life-threatening bacterial infections, are needed to bring these ideas to fruition.

Efficacy of stereotactic radiosurgery for radiation-induced meningiomas.

PURPOSE: Stereotactic radiosurgery is an established treatment option for sporadic meningiomas, though limited data exists for radiation-induced lesions. METHODS: Patients treated with cobalt-60 radiosurgery between October 2005 and December 2018 in an institutional registry were reviewed. Single fraction treatments were prescribed to the 50% isodose line. Lesions were deemed to be radiation-induced according to standard criteria previously established by Cahan et al. RESULTS: A total of 37 patients with 72 lesions were analysed. Median follow up per patient was 44 months (range, 1.4-150.7 months). Median age at initial radiotherapy was 5 years (4 months-48 years), and at radiosurgery was 38 years. Of the 72 lesions, 62 were grade 1 (n = 4) or radiologically-diagnosed (n = 58), six were grade 2 and four were grade 3. Median lesion volume was 2.13 cc (0.04-13.8 cc), while the median radiosurgery margin dose was 13 Gy. Local control, on a per lesion basis, was 88.6% at 5 years (95% confidence interval [CI] 72.3-95.6). For grade 1 or radiologically-diagnosed lesions, local control was 96.6% at 5 years (95% CI 77.9-99.5), whereas those with grade 2 or higher lesions had a local control of 40% at 5 years (95% CI 5.2-75.3, p = 0.005). Radiologic oedema developed in 17 lesions (23.6%) and was symptomatic in 12 patients (16.7%). Doses above 12 Gy were not associated with local control probability (p = 0.292). CONCLUSION: Radiosurgery is an effective treatment option for grade 1 or radiologically-diagnosed radiation-induced meningiomas, with 12 Gy appearing to be a sufficient dose.

Application and validity of the effective medium approximation to the optical properties of nano-textured silicon coated with a dielectric layer.

The emergence of nanotextures in photovoltaics has resulted in challenges associated with optical modelling. Whilst rigorous methods exist to accurately solve these textures, the computational effort required limits the scope of modeling applications. The effective medium approximation (EMA) is a potential alternative to provide rapid modeling results which can be easily integrated with ray tracing of large complex structures. However, the validity of this technique is strongly dependent on the size of features relative to the wavelength of interest, making the application of EMA ambiguous for many situations. This paper aims to address this issue by comparing the simulated results between EMA and finite element methods for three randomly distributed silicon textures with and without a dielectric layer. Criteria for which the EMA approach is valid are proposed and generalized using ratios between root-mean-square roughness, correlation length and incident wavelength, making these limits broadly applicable, beyond that of just the nanotexture under specific solar spectrum regimes. The results in this work apply to random, isotropic textures under normally incident light. Based on the proposed criteria, the validity of different optical simulation techniques for a set of industrial photovoltaic textures is discussed. This analysis reveals a region within which neither geometric optics nor EMA are adequate for calculating the reflectivity of a textured surface, and hence FDTD or other new approaches are required.

Does urinary cytology have a role in haematuria investigations?

OBJECTIVES: To determine the diagnostic accuracy of urinary cytology to diagnose bladder cancer and upper tract urothelial cancer (UTUC) as well as the outcome of patients with a positive urine cytology and normal haematuria investigations in patients in a multicentre prospective observational study of patients investigated for haematuria. PATIENT AND METHODS: The DETECT I study (clinicaltrials.gov NCT02676180) recruited patients presenting with haematuria following referral to secondary case at 40 hospitals. All patients had a cystoscopy and upper tract imaging (renal bladder ultrasound [RBUS] and/ or CT urogram [CTU]). Patients, where urine cytology were performed, were sub-analysed. The reference standard for the diagnosis of bladder cancer and UTUC was histological confirmation of cancer. A positive urine cytology was defined as a urine cytology suspicious for neoplastic cells or atypical cells. RESULTS: Of the 3 556 patients recruited, urine cytology was performed in 567 (15.9%) patients from nine hospitals. Median time between positive urine cytology and endoscopic tumour resection was 27 (IQR: 21.3-33.8) days. Bladder cancer was diagnosed in 39 (6.9%) patients and UTUC in 8 (1.4%) patients. The accuracy of urinary cytology for the diagnosis of bladder cancer and UTUC was: sensitivity 43.5%, specificity 95.7%, positive predictive value (PPV) 47.6% and negative predictive value (NPV) 94.9%. A total of 21 bladder cancers and 5 UTUC were missed. Bladder cancers missed according to grade and stage were as follows: 4 (19%) were ≥ pT2, 2 (9.5%) were G3 pT1, 10 (47.6%) were G3/2 pTa and 5 (23.8%) were G1 pTa. High-risk cancer was confirmed in 8 (38%) patients. There was a marginal improvement in sensitivity (57.7%) for high-risk cancers. When urine cytology was combined with imaging, the diagnostic performance improved with CTU (sensitivity 90.2%, specificity 94.9%) superior to RBUS (sensitivity 66.7%, specificity 96.7%). False positive cytology results were confirmed in 22 patients, of which 12 (54.5%) had further invasive tests and 5 (22.7%) had a repeat cytology. No cancer was identified in these patients during follow-up. CONCLUSIONS: Urine cytology will miss a significant number of muscle-invasive bladder cancer and high-risk disease. Our results suggest that urine cytology should not be routinely performed as part of haematuria investigations. The role of urine cytology in select cases should be considered in the context of the impact of a false positive result leading to further potentially invasive tests conducted under general anaesthesia.

Electron spectroscopy of ionic liquids: experimental identification of atomic orbital contributions to valence electronic structure.

The atomic contributions to valence electronic structure for 37 ionic liquids (ILs) are identified using a combination of variable photon energy XPS, resonant Auger electron spectroscopy (RAES) and a subtraction method. The ILs studied include a diverse range of cationic and anionic structural moieties. We introduce a new parameter for ILs, the energy difference between the energies of the cationic and anionic highest occupied fragment orbitals (HOFOs), which we use to identify the highest occupied molecular orbital (HOMO). The anion gave rise to the HOMO for 25 of the 37 ILs studied here. For 10 of the ILs, the energies of the cationic and anionic HOFOs were the same (within experimental error); therefore, it could not be determined whether the HOMO was from the cation or the anion. For two of the ILs, the HOMO was from the cation and not from the anion; consequently it is energetically more favourable to remove an electron from the cation than the anion for these two ILs. In addition, we used a combination of area normalisation and subtraction of XP spectra to produce what are effectively XP spectra for individual ions; this was achieved for 10 cations and 14 anions.