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The ability to rapidly diagnose, track, and disseminate information for SARS-CoV-2 is critical to minimize its spread. Here, we engineered a portable smartphone-based quantum barcode serological assay device for real-time surveillance of patients infected with SARS-CoV-2. Our device achieved a clinical sensitivity of 90% and specificity of 100% for SARS-CoV-2, as compared to 34% and 100%, respectively, for lateral flow assays in a head-to-head comparison. The lateral flow assay misdiagnosed ∼2 out of 3 SARS-CoV-2 positive patients. Our quantum dot barcode device has ∼3 times greater clinical sensitivity because it is ∼140 times more analytically sensitive than lateral flow assays. Our device can diagnose SARS-CoV-2 at different sampling dates and infectious severity. We developed a databasing app to provide instantaneous results to inform patients, physicians, and public health agencies. This assay and device enable real-time surveillance of SARS-CoV-2 seroprevalence and potential immunity.

COVID-19 has spread globally since its discovery in Hubei province, China in December 2019. A combination of computed tomography imaging, whole genome sequencing, and electron microscopy were initially used to screen and identify SARS-CoV-2, the viral etiology of COVID-19. The aim of this review article is to inform the audience of diagnostic and surveillance technologies for SARS-CoV-2 and their performance characteristics. We describe point-of-care diagnostics that are on the horizon and encourage academics to advance their technologies beyond conception. Developing plug-and-play diagnostics to manage the SARS-CoV-2 outbreak would be useful in preventing future epidemics.

Ruminal synchronization of energy and protein supply is a strategy suggested by nutritionists to increase the efficiency of ruminant metabolic processes such as microbial protein synthesis and to decrease the environmental excretion of nutrients. A so-called synchronization index ( SI ), formulated as a function of the ratio of nitrogen to organic matter release in the rumen, is widely used to quantify and evaluate ruminal synchronization. A main concern is that SI values obtained from the in situ experimental method are influenced by many random factors and therefore SI value, calculated by the currently-used formula, may not represent actual degree of synchronization. Therefore, in this paper, we comprehensively examine sensitivity of SI to random variations (unwanted measurement errors) due to the experimental conditions variability. Evaluations were performed by means of in situ experiments on 3 ruminally fistulated Holstein lactating dairy cows, where 18 different diets were studied. The diets (g/kg DM) were formulated to a range of CP (150–190), NFC (300–400), NDF (310–410), and ADF (169–246). Based on measured data, a set of synthetic data were also generated to study a range of random variations and their effect on SI values. Our results indicated that SI values are quite sensitive to the random variations ( i.e. , significantly decrease as random variations increase). This fact revealed that the currently used SI depends not only on degree of synchronization, but also on degree of random variations due to the inevitable experimental conditions variability. Therefore, the original SI is not fully representative of the actual synchronization when having a high degree of variability. To resolve this problem, we propose a novel approach to calculating SI based on a regression analysis on measured data of nitrogen and organic matter release followed by an analytical derivation of SI based on the regression results. The SI values obtained from the new method showed minimal sensitivity to the random variations. The original method yielded a much lower SI than the new method (0.64 vs. 0.92) for our optimum diet (g/kg DM) (NFC = 350, NDF = 330, ADF = 183, and CP = 165), showing some degrees of asynchrony for this diet. Therefore, we conclude that the new method provides more reliable SI values for determining and quantifying ruminal synchronization.

Mobile phone technology is a perfect companion for point-of-care diagnostics as they come equipped with advanced processors, high resolution cameras, and network connectivity. Despite several academic pursuits, only a few mobile phone diagnostics have been tested in the field, commercialized or achieved regulatory approval. This review will address the challenges associated with developing mobile diagnostics and suggest strategies to overcome them. We aim to provide a resource for researchers to accelerate the development of new diagnostics. Our Account includes an overview of published mobile phone diagnostics and highlights lessons learned from their approach to diagnostic development. Also, we have included recommendations from regulatory and public health agencies, such as the U.S. Food and Drug Administration and World Health Organization, to further guide researchers. We believe that the development of mobile phone point-of-care diagnostics takes place in four distinct steps: (1) Needs and Value Assessment, (2) Technology Development, (3) Preclinical Verification, and (4) Clinical Validation and Field Trials. During each step, we outline developmental strategies to help researchers avoid potential challenges. (1) Researchers commonly develop devices to maximize technical parameters such as sensitivity and time which do not necessarily translate to increased clinical impact. Researchers must focus on assessing specific diagnostic needs and the value which a potential device would offer. (2) Often, researchers claim they have developed devices for feasible implementation at the point-of-care, yet they rely on laboratory resources. Researchers must develop equipment-free devices which are agnostic to any mobile phone. (3) Another challenge researchers face is decreased performance during field evaluations relative to initial laboratory verification. Researchers must ensure that they simulate the field conditions during laboratory verification to achieve successful translation. (4) Finally, proper field testing of devices must be performed in conditions which match that of the final intended use. The future of mobile phone point-of-care diagnostic devices is bright and has the potential to radically change how patients are diagnosed. Before we reach this point, researchers must take a step backward and focus on the first-principles of basic research. The widespread adoption and rapid scaling of these devices can only be achieved once the fundamentals have been considered. The insights and strategies provided here will help researchers avoid pitfalls, streamline development and make better decisions during the development of new diagnostics. Further, we believe this Account can help push the field of mobile diagnostics toward increased productivity, leading to more approved devices and ultimately helping curb the burden of disease worldwide.

Feeding dairy cows with imbalanced, high protein diets can increase levels of urea in serum and ovarian follicular fluid. However, whether and precisely how this compound influences the reproductive physiology of the animals has not yet been determined. The main objective of this study was to evaluate the effect of urea on the viability and function of cultured bovine granulosa cells (bGCs). The bGCs, collected by follicular aspiration, were disrupted until single-cell suspensions were achieved and then cultured in vitro with different urea concentrations (0, 2.5, 5, 8 mM). After 24 hours in culture, bGC growth and viability were evaluated, and frozen for gene expression analysis. Freshly isolated cells (without culture) were collected as a reference. The BioMark™ qPCR platform (Fluidigm Inc.) for gene expression analysis was used to compare the expression levels of 42 genes in non-cultured, and cultured/treated bGCs. The genes evaluated were from the following functional groups: GC-specific, steroid hormone biosynthesis, urea cycle, solute channels/transporters, immediate/early stress response, and ‘housekeeping’. Microscopic evaluation of cultured bGCs showed that urea had a substantial effect on cell morphology. Cell viability was not different between 0 mM (control) and 2.5 mM urea-treated cells (P>0.1), or between 5 mM and 8 mM urea-treated cells (P>0.1). Surprisingly, the 5 mM and 8 mM urea-treated cells showed higher viability than the cells in the control and 2.5 mM groups. Only one gene showed significant differences between control and urea-treated cells (MAPK14; P=0.033). However, 10 genes (AMH, AQP7, CYP19A1, FSHR, GJA1, INHBA, PTGS2, PTX3, TAF11, VNN2) were differentially expressed (P

Cheatgrass (CG; ), an introduced winter annual grass, is an aggressive invader of the sagebrush community in the Western United States. Because of its greater flammability, mature CG constitutes a fire hazard leading to repeated wildfires. One fuel-reduction strategy is livestock grazing. The objective of this study was to evaluate the effects of urea, molasses, or a combination of urea and molasses supplementation of a CG-based diet on digestibility, microbial fermentation, bacterial protein synthesis, and nutrient flow using a dual-flow continuous culture system. Eight fermenters were used in a replicate 4 × 4 Latin square design with four 10-d experimental periods. Experimental treatments (DM basis) were 1) forage only (CON), 2) CG plus urea alone (URE; 1.36% urea), 3) CG plus molasses alone (MOL; 15.9% molasses), and 4) CG plus urea and molasses combined (URE+MOL; 1.28% urea plus 19.3% molasses). Each fermenter was fed 72 g/d of DM, and data were analyzed using the GLIMMIX procedure of SAS (SAS Inst. Inc., Cary, NC). The true digestibilities of NDF and ADF were not affected by diets (0.05). Molasses-containing diets had greater true digestibility of OM ( = 0.02). However, true digestibility of CP was increased when molasses was fed alone (0.01). Molasses-containing diets had lower pH (0.01) and greater VFA concentrations (0.01) compared to those of the other diets. The URE+MOL diet resulted in a greater VFA concentration (0.01). Propionate concentration increased (0.01), whereas acetate concentration decreased (0.01) when molasses alone or in combination with urea was added to the diets. Supplying molasses alone resulted in greater ( = 0.03) total branched-chain VFA compared to the other diets. The concentration of NH-N and total N flow increased (0.01) in response to urea supplementation and was greater (0.01) when urea alone was supplemented in the diet. On the other hand, molasses-supplemented diets yielded more non-ammonia N (0.01) and bacterial N ( = 0.04). Supplementation had no effect ( = 0.83) on bacterial efficiency. Results from this study indicate that the addition of urea and molasses in a CG-based diet could improve nutrient supply to animals, notably VFA supply and microbial N supply; however, in the levels tested in this study, it did not improve CG utilization as assessed by NDF digestion.

Cheatgrass (CG; ), an introduced winter annual grass, is an aggressive invader of the sagebrush community in the Western United States. Because of its greater flammability, mature CG constitutes a fire hazard leading to repeated wildfires. One fuel-reduction strategy is livestock grazing. The objective of this study was to evaluate the effects of urea, molasses, or a combination of urea and molasses supplementation of a CG-based diet on digestibility, microbial fermentation, bacterial protein synthesis, and nutrient flow using a dual-flow continuous culture system. Eight fermenters were used in a replicate 4 × 4 Latin square design with four 10-d experimental periods. Experimental treatments (DM basis) were 1) forage only (CON), 2) CG plus urea alone (URE; 1.36% urea), 3) CG plus molasses alone (MOL; 15.9% molasses), and 4) CG plus urea and molasses combined (URE+MOL; 1.28% urea plus 19.3% molasses). Each fermenter was fed 72 g/d of DM, and data were analyzed using the GLIMMIX procedure of SAS (SAS Inst. Inc., Cary, NC). The true digestibilities of NDF and ADF were not affected by diets ( > 0.05). Molasses-containing diets had greater true digestibility of OM ( = 0.02). However, true digestibility of CP was increased when molasses was fed alone ( < 0.01). Molasses-containing diets had lower pH ( < 0.01) and greater VFA concentrations ( < 0.01) compared to those of the other diets. The URE+MOL diet resulted in a greater VFA concentration ( < 0.01). Propionate concentration increased ( < 0.01), whereas acetate concentration decreased ( < 0.01) when molasses alone or in combination with urea was added to the diets. Supplying molasses alone resulted in greater ( = 0.03) total branched-chain VFA compared to the other diets. The concentration of NH-N and total N flow increased ( < 0.01) in response to urea supplementation and was greater ( < 0.01) when urea alone was supplemented in the diet. On the other hand, molasses-supplemented diets yielded more non-ammonia N ( < 0.01) and bacterial N ( = 0.04). Supplementation had no effect ( = 0.83) on bacterial efficiency. Results from this study indicate that the addition of urea and molasses in a CG-based diet could improve nutrient supply to animals, notably VFA supply and microbial N supply; however, in the levels tested in this study, it did not improve CG utilization as assessed by NDF digestion.