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AN3380 - Driving a Metronome Using a PIC Microcontroller

AN3380 - Driving a Metronome Using a PIC Microcontroller




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US private equity firm Kohlberg Kravis Roberts to invest Rs 750 crore in 2 realty projects in metros

MUMBAI: US private equity firm Kohlberg Kravis Roberts & Co has made its entry in the country’s real estate sector by finalising investments of Rs 750 crore in two property projects. KKR has struck a structured debt transaction for Rs 400 crore for the Bhartiya Group’s integrated township project in Bangalore, two people with direct knowledge of the transactions said. It also agreed to provide a Rs 350 crore structured loan to the Wadhwa Group’s luxury home project in west central Mumbai, they said. The group will use the money to repay other lenders of the project, where the cost of apartments ranges from Rs 1.5 crore to Rs 10 […]




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Mumbai: Authority commences work on a new underground metro corridor

The Mumbai Metropolitan Region Development Authority (MMRDA) has begun the construction of 3.1 km-long new Metro Line 7A. The proposed metro corridor would comprise two stations and would connect Line 7 with the Chhatrapati Shivaji International Airport. The Mumbai Metropolitan Region Development Authority (MMRDA) has commenced the development of the Metro Line 7A.  The reach of the new metro would be 3.1 km, out of which 2.1 km-long section would be underground and would include a twin-tunnel. The corridor would establish connectivity between Metro Line 7 and the Chhatrapati Shivaji International Airport. Other areas that are expected to benefit from the improved connectivity include Andheri and Dahisar (East). According to an MMRDA […]




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JBL geluid én gemakkelijk muziek streamen: Maak kennis met de JBL® Link Portable en Link Music

Van knallende baslijnen tot vloeiende gitaarsolo’s, JBL introduceert de JBL Link Portable en Link Music. Ze zijn net zo handig als ze mooi zijn, de speakers zijn voorzien van 360 graden JBL’s kenmerkende sound, Wifi- en Bluetooth-connectiviteit en ingebouwde Chromecast en Google assistent.




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Bouw een feest met de draadloze JBL® Pulse 4

360° JBL geluid. Een fantastische lichtshow. Met de Pulse 4 van JBL zorg jij voor een goede sfeer, of je nu wilt feesten of chillen. Van woonkamer tot strandfeest (en alles daartussenin), de nieuwe JBL Pulse 4 staat voor je klaar.




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JBL verlegt de lat met een nieuwe Soundbar serie

Een gestroomlijnd model, krachtige bas en nog intenser geluid: JBL tilt home entertainment naar een hoger plan. Op IFA worden vandaag drie splinternieuwe producten gelanceerd: een compacte alles-in-één oplossing, een kamervullende surround-sound en een diepe bas Bar. Voor ieder wat wils in de nieuwe Soundbar serie.




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How I made the world’s most accurate thermometer – using sound

Join Michael De Podesta as he explains how he made the world’s most precise thermometer – and demonstrates its principle live on stage




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Metallic hydrogen would be the ultimate fuel - if we can make it

The universe’s most common element could also be its most wondrous. Two different groups of researchers say they've made it - but can either claim withstand scrutiny?




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Liquid metal that floats on water could make transformable robots

A lightweight liquid metal alloy that is less dense than water could be used to make exoskeletons and transformable flexible robots




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No clowning around with masks on Mexico City metro

A campaign in Mexico City to get residents to wear face masks is now reinforced with a new secret weapon: clowns. They're telling metro riders, 'Wear a face mask -- don't be a clown!' as they spray riders' hands with disinfectant. Gavino Garay has more.




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This desert ant can run at the equivalent of 600 kilometres per hour

Desert ants zigzag around the searing sand at high speed but they always manage to find their way home. A new book explains their amazing abilities




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Earth's first life may have fuelled itself with a metal metabolism

The first living organisms had to make essential carbon-based chemicals, and they may have done it by harnessing the chemical power of metals like nickel




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NASA’s deep-space mission to a $10 quintillion all-metal world

The unique metal asteroid Psyche may be a space miner's fantasy – but there are better reasons to want to visit it, says mission leader Lindy Elkins-Tanton




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Huge 30-kilometre wide meteorite crater found under Greenland glacier

Radar surveys have revealed a crater left when a kilometre-wide asteroid hit Greenland – and the impact could explain a climate mystery




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Scientists chasing waterfalls discovered something they aren't used to

We often think waterfalls indicate ancient tectonic or glacial activity – but it turns out they can form all by themselves without these external influences




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Meltwater from Greenland could raise sea level an extra 7 centimetres

Melting and refreezing is turning the absorbent surface snow of Greenland into solid ice, an effect that could contribute to sea level rises




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'Play It Loud: Instruments of Rock & Roll' exhibit set to launch at New York's 'Met' Museum

It's only 'Rock and Roll,' but one of the world's preeminent museums likes it; New York's Metropolitan Museum of Art will display instruments from Chuck Berry, The Rolling Stones, Kurt Cobain, Lady Gaga and more until October 1. Rough Cut. (No Reporter Narration.)




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Metallic hydrogen would be the ultimate fuel - if we can make it

The universe’s most common element could also be its most wondrous. Two different groups of researchers say they've made it - but can either claim withstand scrutiny?




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No clowning around with masks on Mexico City metro

A campaign in Mexico City to get residents to wear face masks is now reinforced with a new secret weapon: clowns. They're telling metro riders, 'Wear a face mask -- don't be a clown!' as they spray riders' hands with disinfectant. Gavino Garay has more.




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The Met showcases Islamic art as a response to Trump's Muslim ban

The Metropolitan Museum of Art in New York leads Islamic art tours to improve understanding of its contributions to the world heritage. Fred Katayama reports.




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No clowning around with masks on Mexico City metro

A campaign in Mexico City to get residents to wear face masks is now reinforced with a new secret weapon: clowns. They're telling metro riders, 'Wear a face mask -- don't be a clown!' as they spray riders' hands with disinfectant. Gavino Garay has more.




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Fracking wells in the US are leaking loads of planet-warming methane

Satellites have revealed the fracking heartland of the US is leaking methane, a powerful greenhouse gas, at a record-breaking rate.




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methimazole, Tapazole

Title: methimazole, Tapazole
Category: Medications
Created: 2/24/2001 12:00:00 AM
Last Editorial Review: 10/15/2019 12:00:00 AM




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Drugs Can Sometimes Prevent Migraines, but at a Cost

Title: Drugs Can Sometimes Prevent Migraines, but at a Cost
Category: Health News
Created: 4/29/2013 10:35:00 AM
Last Editorial Review: 4/29/2013 12:00:00 AM




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Cosmetic Procedures for Arms on the Rise, Plastic Surgeons Say

Title: Cosmetic Procedures for Arms on the Rise, Plastic Surgeons Say
Category: Health News
Created: 4/29/2013 12:35:00 PM
Last Editorial Review: 4/30/2013 12:00:00 AM




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Lipsticks, Glosses Contain Toxic Metals: Report

Title: Lipsticks, Glosses Contain Toxic Metals: Report
Category: Health News
Created: 5/2/2013 10:35:00 AM
Last Editorial Review: 5/2/2013 12:00:00 AM




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Helmets Not Helpful for Babies With 'Flat Head' Syndrome: Study

Title: Helmets Not Helpful for Babies With 'Flat Head' Syndrome: Study
Category: Health News
Created: 5/2/2014 9:35:00 AM
Last Editorial Review: 5/2/2014 12:00:00 AM




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Health Tip: Fitting a Bicycle Helmet

Title: Health Tip: Fitting a Bicycle Helmet
Category: Health News
Created: 4/29/2015 12:00:00 AM
Last Editorial Review: 4/29/2015 12:00:00 AM




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Temporarily Turning Blue Sometimes Normal for Babies, Doctors Say

Title: Temporarily Turning Blue Sometimes Normal for Babies, Doctors Say
Category: Health News
Created: 4/25/2016 12:00:00 AM
Last Editorial Review: 4/25/2016 12:00:00 AM




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Not Just Opioids: Deaths Tied to Cocaine, Meth Are Soaring, Too

Title: Not Just Opioids: Deaths Tied to Cocaine, Meth Are Soaring, Too
Category: Health News
Created: 5/2/2019 12:00:00 AM
Last Editorial Review: 5/3/2019 12:00:00 AM




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What Is a Pulse Oximeter, and Should You Get One to Warn of COVID-19?

Title: What Is a Pulse Oximeter, and Should You Get One to Warn of COVID-19?
Category: Health News
Created: 4/28/2020 12:00:00 AM
Last Editorial Review: 4/29/2020 12:00:00 AM




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Sometimes, Aspirin May Be Enough to Ease Migraines

Title: Sometimes, Aspirin May Be Enough to Ease Migraines
Category: Health News
Created: 12/10/2019 12:00:00 AM
Last Editorial Review: 12/10/2019 12:00:00 AM




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Laser Process May Kill Bacteria on Metal Surfaces

Title: Laser Process May Kill Bacteria on Metal Surfaces
Category: Health News
Created: 4/16/2020 12:00:00 AM
Last Editorial Review: 4/17/2020 12:00:00 AM




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Endometriosis Risk Can Be Predicted in Young Girls: Study

Title: Endometriosis Risk Can Be Predicted in Young Girls: Study
Category: Health News
Created: 3/10/2020 12:00:00 AM
Last Editorial Review: 3/10/2020 12:00:00 AM




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Tukysa Approved for Unresectable, Metastatic HER2-Positive Breast Cancer

Title: Tukysa Approved for Unresectable, Metastatic HER2-Positive Breast Cancer
Category: Health News
Created: 4/20/2020 12:00:00 AM
Last Editorial Review: 4/21/2020 12:00:00 AM




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FDA Approves Trodelvy for Metastatic Triple-Negative Breast Cancer

Title: FDA Approves Trodelvy for Metastatic Triple-Negative Breast Cancer
Category: Health News
Created: 4/24/2020 12:00:00 AM
Last Editorial Review: 4/24/2020 12:00:00 AM




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Phase I Dose-Escalation and -Expansion Study of Telisotuzumab (ABT-700), an Anti-c-Met Antibody, in Patients with Advanced Solid Tumors

This first-in-human phase I study evaluated the pharmacokinetics, safety, and preliminary efficacy of telisotuzumab, formerly called ABT-700, an antagonistic antibody directed against c-Met. For dose escalation (3+3 design), 3 to 6 patients with advanced solid tumors were enrolled into four dose cohorts (5–25 mg/kg). In the dose-expansion phase, a subset of patients was prospectively selected for MET amplification (FISH screening). Patients received telisotuzumab intravenously on day 1 every 21 days. For dose expansion, 15 mg/kg was chosen as the dose on the basis of safety, pharmacokinetics, and other data from the escalation cohorts. Forty-five patients were enrolled and received at least one dose of telisotuzumab (dose escalation, n = 15; dose expansion, n = 30). Telisotuzumab showed a linear pharmacokinetics profile; peak plasma concentration was proportional to dose level. There were no acute infusion reactions and no dose-limiting toxicities were observed. The most common treatment-related adverse events included hypoalbuminemia (n = 9, 20.0%) and fatigue (n = 5, 11.1%). By Response Evaluation Criteria In Solid Tumors (RECIST), 4 of 10 (40.0%) patients with MET-amplified tumors had confirmed partial response in target lesions (one ovarian, two gastric, and one esophageal), two (20.0%) had stable disease, three (30.0%) had progressive disease; one patient was unable to be evaluated. Among patients with nonamplified tumors (n = 35), no objective responses were observed; however, 11 patients had stable disease per RECIST criteria. In conclusion, telisotuzumab has an acceptable safety profile with clinical activity observed in patients with MET-amplified advanced solid tumors.




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Identification of ALDH1A3 as a Viable Therapeutic Target in Breast Cancer Metastasis-Initiating Cells

The development of efficacious therapies targeting metastatic spread of breast cancer to the brain represents an unmet clinical need. Accordingly, an improved understanding of the molecular underpinnings of central nervous system spread and progression of breast cancer brain metastases (BCBM) is required. In this study, the clinical burden of disease in BCBM was investigated, as well as the role of aldehyde dehydrogenase 1A3 (ALDH1A3) in the metastatic cascade leading to BCBM development. Initial analysis of clinical survival trends for breast cancer and BCBM determined improvement of breast cancer survival rates; however, this has failed to positively affect the prognostic milestones of triple-negative breast cancer (TNBC) brain metastases (BM). ALDH1A3 and a representative epithelial–mesenchymal transition (EMT) gene signature (mesenchymal markers, CD44 or Vimentin) were compared in tumors derived from BM, lung metastases (LM), or bone metastases (BoM) of patients as well as mice after injection of TNBC cells. Selective elevation of the EMT signature and ALDH1A3 were observed in BM, unlike LM and BoM, especially in the tumor edge. Furthermore, ALDH1A3 was determined to play a role in BCBM establishment via regulation of circulating tumor cell adhesion and migration phases in the BCBM cascade. Validation through genetic and pharmacologic inhibition of ALDH1A3 via lentiviral shRNA knockdown and a novel small-molecule inhibitor demonstrated selective inhibition of BCBM formation with prolonged survival of tumor-bearing mice. Given the survival benefits via targeting ALDH1A3, it may prove an effective therapeutic strategy for BCBM prevention and/or treatment.




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Residents Perspectives on and Application of Dental Public Health Competencies Using Case-Based Methods

The aims of this study were to qualitatively assess dental public health (DPH) residents’ perspectives on teaching methods for DPH competencies and to develop and implement a case-based simulation to address those competencies, constructed on the basis of the qualitative assessment. Focus group discussions were conducted with 18 DPH residents enrolled in two university-based DPH programs. Topic areas discussed in the two focus groups were perceived value of DPH competencies, ways to acquire new DPH skills/abilities, and additional skills/abilities needed by DPH residents. The focus groups’ responses showed that the residents felt competent in the analytical thinking competencies such as research methodology and critiquing literature. They emphasized the importance of learning leadership skills and reported feeling somewhat uncertain about their mastery of the policy and advocacy and system evaluation competencies. Of the two distinct categories of DPH skills and competencies— analytical/critical thinking and practical competencies—these residents reported that a greater proportion of time needed to be devoted to integrating the practical competencies into their education. Based on the residents’ feedback, the authors developed a structured seminar series taking a case-based approach to simulate real-world DPH problems, using real and semi-hypothetical planning projects to meet the residents’ perceived needs and covering gaps between didactic learning and practice.




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Top-Cited Articles from Dental Education Journals, 2009 to 2018: A Bibliometric Analysis

The number of citations an article receives is an important indicator to quantify its influence in its field. The aim of this study was to identify and analyze the characteristics of the 50 top-cited articles addressing dental education published in two journals dedicated to dental education (European Journal of Dental Education and Journal of Dental Education). The Web of Science database was searched to retrieve the 50 most-cited articles from the two journals in December 2018. The top-cited articles were analyzed for journal of publication, number of citations, institution and country of origin, year of publication, study type, keywords, theme and subtheme, and international collaborations. The results showed the 50 top-cited articles were cited between 24 and 146 times each. The majority of these top-cited articles (n=34) were published in the Journal of Dental Education. Half (n=25) of the articles were by authors in the U.S. The most common study types were surveys (n=26) and reviews (n=10). The main themes of these top-cited articles were curriculum and learner characteristics. This bibliometric analysis can serve as a reference for recognizing studies with the most impact in the scholarship of dental education.




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A Systematic Meta-Analysis of the Effect of Interprofessional Education on Health Professions Students Attitudes

Interprofessional education (IPE) is based on collaborative practices that increase the occasions for communication among those in various health professions. However, there is a paucity of literature about the effectiveness of IPE programs in health professions education. The aim of this systematic review and meta-analysis was to objectively assess the literature on the effectiveness of IPE in improving health professions students’ attitudes after training. The major scholarly databases were searched for relevant IPE studies involving predoctoral health professions students. Two independent researchers selected the studies, extracted the data, and assessed the quality of the studies. Meta-analyses of the outcomes were performed using random effects models. Sixteen articles were ultimately selected for detailed review and meta-analysis. The meta-analysis showed that IPE training had a significant influence on students’ understanding of collaboration and resulted in better attitudes about interprofessional teamwork. Subscale analysis showed that one subscale score (roles and responsibilities) did not statistically significantly improve after IPE training (p=0.06), whereas the other four subscale items showed statistically significant improvements (p<0.01). The test for overall effects showed that IPE training had a significantly positive influence on students’ attitudes about IPE (Z=6.85, p<0.01). Subgroup results showed that medical students had more positive attitudes about IPE than did dental students. Regardless of profession, women students responded with significantly more positive feedback than did men students (p=0.02). These results suggest that intervention through IPE training has had positive effects in health professions education. Gender was an important factor impacting the outcomes of IPE. However, further clinical practice interventions may be helpful to enhance the IPE competence of health professions students.




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SSO and other putative inhibitors of FA transport across membranes by CD36 disrupt intracellular metabolism, but do not affect FA translocation [Research Articles]

Membrane-bound proteins have been proposed to mediate the transport of long-chain FA (LCFA) transport through the plasma membrane (PM). These proposals are based largely on reports that PM transport of LCFAs can be blocked by a number of enzymes and purported inhibitors of LCFA transport. Here, using the ratiometric pH indicator (2',7'-bis-(2-carboxyethyl)-5-(and-6-)-carboxyfluorescein and acrylodated intestinal FA-binding protein-based dual fluorescence assays, we investigated the effects of nine inhibitors of the putative FA transporter protein CD36 on the binding and transmembrane movement of LCFAs. We particularly focused on sulfosuccinimidyl oleate (SSO), reported to be a competitive inhibitor of CD36-mediated LCFA transport. Using these assays in adipocytes and inhibitor-treated protein-free lipid vesicles, we demonstrate that rapid LCFA transport across model and biological membranes remains unchanged in the presence of these purported inhibitors. We have previously shown in live cells that CD36 does not accelerate the transport of unesterified LCFAs across the PM. Our present experiments indicated disruption of LCFA metabolism inside the cell within minutes upon treatment with many of the "inhibitors" previously assumed to inhibit LCFA transport across the PM. Furthermore, using confocal microscopy and a specific anti-SSO antibody, we found that numerous intracellular and PM-bound proteins are SSO-modified in addition to CD36. Our results support the hypothesis that LCFAs diffuse rapidly across biological membranes and do not require an active protein transporter for their transmembrane movement.




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Vitamin E does not prevent Western diet-induced NASH progression and increases metabolic flux dysregulation in mice [Research Articles]

Fatty liver involves ectopic lipid accumulation and dysregulated hepatic oxidative metabolism, which can progress to a state of elevated inflammation and fibrosis referred to as nonalcoholic steatohepatitis (NASH). The factors that control progression from simple steatosis to NASH are not fully known. Here, we tested the hypothesis that dietary vitamin E (VitE) supplementation would prevent NASH progression and associated metabolic alterations induced by a Western diet (WD). Hyperphagic melanocortin-4 receptor-deficient (MC4R–/–) mice were fed chow, chow+VitE, WD, or WD+VitE starting at 8 or 20 weeks of age. All groups exhibited extensive hepatic steatosis by the end of the study (28 weeks of age). WD feeding exacerbated liver disease severity without inducing proportional changes in liver triglycerides. Eight weeks of WD accelerated liver pyruvate cycling, and 20 weeks of WD extensively upregulated liver glucose and oxidative metabolism assessed by 2H/13C flux analysis. VitE supplementation failed to reduce the histological features of NASH. Rather, WD+VitE increased the abundance and saturation of liver ceramides and accelerated metabolic flux dysregulation compared with 8 weeks of WD alone. In summary, VitE did not limit NASH pathogenesis in genetically obese mice, but instead increased some indicators of metabolic dysfunction.




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Commentary on SSO and other putative inhibitors of FA transport across membranes by CD36 disrupt intracellular metabolism, but do not affect fatty acid translocation [Commentaries]




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Direct Observation of the Dynamics of Single-Cell Metabolic Activity during Microbial Diauxic Growth

ABSTRACT

Population-level analyses are rapidly becoming inadequate to answer many of biomedical science and microbial ecology’s most pressing questions. The role of microbial populations within ecosystems and the evolutionary selective pressure on individuals depend fundamentally on the metabolic activity of single cells. Yet, many existing single-cell technologies provide only indirect evidence of metabolic specialization because they rely on correlations between transcription and phenotype established at the level of the population to infer activity. In this study, we take a top-down approach using isotope labels and secondary ion mass spectrometry to track the uptake of carbon and nitrogen atoms from different sources into biomass and directly observe dynamic changes in anabolic specialization at the level of single cells. We investigate the classic microbiological phenomenon of diauxic growth at the single-cell level in the model methylotroph Methylobacterium extorquens. In nature, this organism inhabits the phyllosphere, where it experiences diurnal changes in the available carbon substrates, necessitating an overhaul of central carbon metabolism. We show that the population exhibits a unimodal response to the changing availability of viable substrates, a conclusion that supports the canonical model but has thus far been supported by only indirect evidence. We anticipate that the ability to monitor the dynamics of anabolism in individual cells directly will have important applications across the fields of ecology, medicine, and biogeochemistry, especially where regulation downstream of transcription has the potential to manifest as heterogeneity that would be undetectable with other existing single-cell approaches.

IMPORTANCE Understanding how genetic information is realized as the behavior of individual cells is a long-term goal of biology but represents a significant technological challenge. In clonal microbial populations, variation in gene regulation is often interpreted as metabolic heterogeneity. This follows the central dogma of biology, in which information flows from DNA to RNA to protein and ultimately manifests as activity. At present, DNA and RNA can be characterized in single cells, but the abundance and activity of proteins cannot. Inferences about metabolic activity usually therefore rely on the assumption that transcription reflects activity. By tracking the atoms from which they build their biomass, we make direct observations of growth rate and substrate specialization in individual cells throughout a period of growth in a changing environment. This approach allows the flow of information from DNA to be constrained from the distal end of the regulatory cascade and will become an essential tool in the rapidly advancing field of single-cell metabolism.




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A Shift in Central Metabolism Accompanies Virulence Activation in Pseudomonas aeruginosa

ABSTRACT

The availability of energy has significant impact on cell physiology. However, the role of cellular metabolism in bacterial pathogenesis is not understood. We investigated the dynamics of central metabolism during virulence induction by surface sensing and quorum sensing in early-stage biofilms of the multidrug-resistant bacterium Pseudomonas aeruginosa. We established a metabolic profile for P. aeruginosa using fluorescence lifetime imaging microscopy (FLIM), which reports the activity of NADH in live cells. We identified a critical growth transition period during which virulence is activated. We performed FLIM measurements and direct measurements of NADH and NAD+ concentrations during this period. Here, planktonic (low-virulence) and surface-attached (virulence-activated) populations diverged into distinct metabolic states, with the surface-attached population exhibiting FLIM lifetimes that were associated with lower levels of enzyme-bound NADH and decreasing total NAD(H) production. We inhibited virulence by perturbing central metabolism using citrate and pyruvate, which further decreased the enzyme-bound NADH fraction and total NAD(H) production and suggested the involvement of the glyoxylate pathway in virulence activation in surface-attached populations. In addition, we induced virulence at an earlier time using the electron transport chain oxidase inhibitor antimycin A. Our results demonstrate the use of FLIM to noninvasively measure NADH dynamics in biofilms and suggest a model in which a metabolic rearrangement accompanies the virulence activation period.

IMPORTANCE The rise of antibiotic resistance requires the development of new strategies to combat bacterial infection and pathogenesis. A major direction has been the development of drugs that broadly target virulence. However, few targets have been identified due to the species-specific nature of many virulence regulators. The lack of a virulence regulator that is conserved across species has presented a further challenge to the development of therapeutics. Here, we identify that NADH activity has an important role in the induction of virulence in the pathogen P. aeruginosa. This finding, coupled with the ubiquity of NADH in bacterial pathogens, opens up the possibility of targeting enzymes that process NADH as a potential broad antivirulence approach.




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Tracking a Global Threat: a New Genotyping Method for Candida auris

ABSTRACT

Over the past decade, Candida auris has emerged as an urgent threat to public health. Initially reported from cases of ear infections in Japan and Korea, C. auris has since been detected around the world. While whole-genome sequencing has been extensively used to trace the genetic relationships of the global emergence and local outbreaks, a recent report in mBio describes a targeted genotyping method as a rapid and inexpensive method for classifying C. auris isolates (T. de Groot, Y. Puts, I. Berrio, A. Chowdhary, and J. F. Meis, mBio 11:e02971-19, https://doi.org/10.1128/mBio.02971-19, 2020).




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A Solution to Antifolate Resistance in Group B Streptococcus: Untargeted Metabolomics Identifies Human Milk Oligosaccharide-Induced Perturbations That Result in Potentiation of Trimethoprim

ABSTRACT

Adjuvants can be used to potentiate the function of antibiotics whose efficacy has been reduced by acquired or intrinsic resistance. In the present study, we discovered that human milk oligosaccharides (HMOs) sensitize strains of group B Streptococcus (GBS) to trimethoprim (TMP), an antibiotic to which GBS is intrinsically resistant. Reductions in the MIC of TMP reached as high as 512-fold across a diverse panel of isolates. To better understand HMOs’ mechanism of action, we characterized the metabolic response of GBS to HMO treatment using ultrahigh-performance liquid chromatography–high-resolution tandem mass spectrometry (UPLC-HRMS/MS) analysis. These data showed that when challenged by HMOs, GBS undergoes significant perturbations in metabolic pathways related to the biosynthesis and incorporation of macromolecules involved in membrane construction. This study represents reports the metabolic characterization of a cell that is perturbed by HMOs.

IMPORTANCE Group B Streptococcus is an important human pathogen that causes serious infections during pregnancy which can lead to chorioamnionitis, funisitis, premature rupture of gestational membranes, preterm birth, neonatal sepsis, and death. GBS is evolving antimicrobial resistance mechanisms, and the work presented in this paper provides evidence that prebiotics such as human milk oligosaccharides can act as adjuvants to restore the utility of antibiotics.




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Phosphoric Metabolites Link Phosphate Import and Polysaccharide Biosynthesis for Candida albicans Cell Wall Maintenance

ABSTRACT

The Candida albicans high-affinity phosphate transporter Pho84 is required for normal Target of Rapamycin (TOR) signaling, oxidative stress resistance, and virulence of this fungal pathogen. It also contributes to C. albicans’ tolerance of two antifungal drug classes, polyenes and echinocandins. Echinocandins inhibit biosynthesis of a major cell wall component, beta-1,3-glucan. Cells lacking Pho84 were hypersensitive to other forms of cell wall stress beyond echinocandin exposure, while their cell wall integrity signaling response was weak. Metabolomics experiments showed that levels of phosphoric intermediates, including nucleotides like ATP and nucleotide sugars, were low in pho84 mutant compared to wild-type cells recovering from phosphate starvation. Nonphosphoric precursors like nucleobases and nucleosides were elevated. Outer cell wall phosphomannan biosynthesis requires a nucleotide sugar, GDP-mannose. The nucleotide sugar UDP-glucose is the substrate of enzymes that synthesize two major structural cell wall polysaccharides, beta-1,3- and beta-1,6-glucan. Another nucleotide sugar, UDP-N-acetylglucosamine, is the substrate of chitin synthases which produce a stabilizing component of the intercellular septum and of lateral cell walls. Lack of Pho84 activity, and phosphate starvation, potentiated pharmacological or genetic perturbation of these enzymes. We posit that low substrate concentrations of beta-d-glucan- and chitin synthases, together with pharmacologic inhibition of their activity, diminish enzymatic reaction rates as well as the yield of their cell wall-stabilizing products. Phosphate import is not conserved between fungal and human cells, and humans do not synthesize beta-d-glucans or chitin. Hence, inhibiting these processes simultaneously could yield potent antifungal effects with low toxicity to humans.

IMPORTANCE Candida species cause hundreds of thousands of invasive infections with high mortality each year. Developing novel antifungal agents is challenging due to the many similarities between fungal and human cells. Maintaining phosphate balance is essential for all organisms but is achieved completely differently by fungi and humans. A protein that imports phosphate into fungal cells, Pho84, is not present in humans and is required for normal cell wall stress resistance and cell wall integrity signaling in C. albicans. Nucleotide sugars, which are phosphate-containing building block molecules for construction of the cell wall, are diminished in cells lacking Pho84. Cell wall-constructing enzymes may be slowed by lack of these building blocks, in addition to being inhibited by drugs. Combined targeting of Pho84 and cell wall-constructing enzymes may provide a strategy for antifungal therapy by which two sequential steps of cell wall maintenance are blocked for greater potency.




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Activity and Metabolic Versatility of Complete Ammonia Oxidizers in Full-Scale Wastewater Treatment Systems

ABSTRACT

The recent discovery of complete ammonia oxidizers (comammox) contradicts the paradigm that chemolithoautotrophic nitrification is always catalyzed by two different microorganisms. However, our knowledge of the survival strategies of comammox in complex ecosystems, such as full-scale wastewater treatment plants (WWTPs), remains limited. Analyses of genomes and in situ transcriptomes of four comammox organisms from two full-scale WWTPs revealed that comammox were active and showed a surprisingly high metabolic versatility. A gene cluster for the utilization of urea and a gene encoding cyanase suggest that comammox may use diverse organic nitrogen compounds in addition to free ammonia as the substrates. The comammox organisms also encoded the genomic potential for multiple alternative energy metabolisms, including respiration with hydrogen, formate, and sulfite as electron donors. Pathways for the biosynthesis and degradation of polyphosphate, glycogen, and polyhydroxyalkanoates as intracellular storage compounds likely help comammox survive unfavorable conditions and facilitate switches between lifestyles in fluctuating environments. One of the comammox strains acquired from the anaerobic tank encoded and transcribed genes involved in homoacetate fermentation or in the utilization of exogenous acetate, both pathways being unexpected in a nitrifying bacterium. Surprisingly, this strain also encoded a respiratory nitrate reductase which has not yet been found in any other Nitrospira genome and might confer a selective advantage to this strain over other Nitrospira strains in anoxic conditions.

IMPORTANCE The discovery of comammox in the genus Nitrospira changes our perception of nitrification. However, genomes of comammox organisms have not been acquired from full-scale WWTPs, and very little is known about their survival strategies and potential metabolisms in complex wastewater treatment systems. Here, four comammox metagenome-assembled genomes and metatranscriptomic data sets were retrieved from two full-scale WWTPs. Their impressive and—among nitrifiers—unsurpassed ecophysiological versatility could make comammox Nitrospira an interesting target for optimizing nitrification in current and future bioreactor configurations.