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  1. Article ; Online: Early Estimates of Updated 2023-2024 (Monovalent XBB.1.5) COVID-19 Vaccine Effectiveness Against Symptomatic SARS-CoV-2 Infection Attributable to Co-Circulating Omicron Variants Among Immunocompetent Adults - Increasing Community Access to Testing Program, United States, September 2023-January 2024.

    Link-Gelles, Ruth / Ciesla, Allison Avrich / Mak, Josephine / Miller, Joseph D / Silk, Benjamin J / Lambrou, Anastasia S / Paden, Clinton R / Shirk, Philip / Britton, Amadea / Smith, Zachary R / Fleming-Dutra, Katherine E

    MMWR. Morbidity and mortality weekly report

    2024  Volume 73, Issue 4, Page(s) 77–83

    Abstract: On September 12, 2023, CDC's Advisory Committee on Immunization Practices recommended updated 2023-2024 (updated) COVID-19 vaccination with a monovalent XBB.1.5-derived vaccine for all persons aged ≥6 months to prevent COVID-19, including severe disease. ...

    Abstract On September 12, 2023, CDC's Advisory Committee on Immunization Practices recommended updated 2023-2024 (updated) COVID-19 vaccination with a monovalent XBB.1.5-derived vaccine for all persons aged ≥6 months to prevent COVID-19, including severe disease. During fall 2023, XBB lineages co-circulated with JN.1, an Omicron BA.2.86 lineage that emerged in September 2023. These variants have amino acid substitutions that might increase escape from neutralizing antibodies. XBB lineages predominated through December 2023, when JN.1 became predominant in the United States. Reduction or failure of spike gene (S-gene) amplification (i.e., S-gene target failure [SGTF]) in real-time reverse transcription-polymerase chain reaction testing is a time-dependent, proxy indicator of JN.1 infection. Data from the Increasing Community Access to Testing SARS-CoV-2 pharmacy testing program were analyzed to estimate updated COVID-19 vaccine effectiveness (VE) (i.e., receipt versus no receipt of updated vaccination) against symptomatic SARS-CoV-2 infection, including by SGTF result. Among 9,222 total eligible tests, overall VE among adults aged ≥18 years was 54% (95% CI = 46%-60%) at a median of 52 days after vaccination. Among 2,199 tests performed at a laboratory with SGTF testing, VE 60-119 days after vaccination was 49% (95% CI = 19%-68%) among tests exhibiting SGTF and 60% (95% CI = 35%-75%) among tests without SGTF. Updated COVID-19 vaccines provide protection against symptomatic infection, including against currently circulating lineages. CDC will continue monitoring VE, including for expected waning and against severe disease. All persons aged ≥6 months should receive an updated COVID-19 vaccine dose.
    MeSH term(s) United States/epidemiology ; Adult ; Humans ; Adolescent ; COVID-19 Vaccines ; COVID-19/diagnosis ; COVID-19/epidemiology ; COVID-19/prevention & control ; Vaccine Efficacy ; SARS-CoV-2
    Chemical Substances COVID-19 Vaccines
    Language English
    Publishing date 2024-02-01
    Publishing country United States
    Document type Journal Article
    ZDB-ID 412775-4
    ISSN 1545-861X ; 0149-2195
    ISSN (online) 1545-861X
    ISSN 0149-2195
    DOI 10.15585/mmwr.mm7304a2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Generation of high-energy, Gaussian laser pulses with tunable duration from 100 picoseconds to 1 millisecond.

    Miller, Joseph D / Slipchenko, Mikhail N / Felver, Josef / Roy, Sukesh

    Optics express

    2020  Volume 28, Issue 25, Page(s) 37811–37826

    Abstract: In this work, a variable-pulse-oscillator is developed and coupled with a burst-mode amplifier for generation of high-energy laser pulses with width of 100 ps to 1 ms and near-Gaussian temporal pulse shape. Pulse energy as high as 600 mJ is demonstrated ... ...

    Abstract In this work, a variable-pulse-oscillator is developed and coupled with a burst-mode amplifier for generation of high-energy laser pulses with width of 100 ps to 1 ms and near-Gaussian temporal pulse shape. Pulse energy as high as 600 mJ is demonstrated at 1064 nm, with a super-Gaussian spatial profile and beam quality as good as 1.6 times the diffraction limit. A time-dependent pulse amplification model is developed and is in general agreement with experimentally measured values of output pulse energy and temporal pulse shape of the amplified pulses. Key performance parameters (pulse energy, temporal pulse shape, and spatial beam profile and quality) are analyzed as a function of pulse width across seven orders of magnitude. Additionally, the model is used to elucidate deviations between the simulated and experimental data, showing that the relationship between pulse width and output pulse energy is dominated by the variable-pulse-width oscillator performance, not the burst-mode amplifier.
    Language English
    Publishing date 2020-12-28
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1491859-6
    ISSN 1094-4087 ; 1094-4087
    ISSN (online) 1094-4087
    ISSN 1094-4087
    DOI 10.1364/OE.409546
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: CH and NO planar laser-induced fluorescence and Rayleigh-scattering in turbulent flames using a multimode optical parametric oscillator.

    Miller, Joseph D / Tröger, Johannes W / Engel, Sascha R / Seeger, Thomas / Leipertz, Alfred / Meyer, Terrence R

    Applied optics

    2020  Volume 60, Issue 1, Page(s) 98–108

    Abstract: An optical parametric oscillator (OPO) is developed and characterized for the simultaneous generation of ultraviolet (UV) and near-UV nanosecond laser pulses for the single-shot Rayleigh scattering and planar laser-induced-fluorescence (PLIF) imaging of ... ...

    Abstract An optical parametric oscillator (OPO) is developed and characterized for the simultaneous generation of ultraviolet (UV) and near-UV nanosecond laser pulses for the single-shot Rayleigh scattering and planar laser-induced-fluorescence (PLIF) imaging of methylidyne (CH) and nitric oxide (NO) in turbulent flames. The OPO is pumped by a multichannel, 8-pulse Nd:YAG laser cluster that produces up to 225 mJ/pulse at 355 nm with pulse spacing of 100 µs. The pulsed OPO has a conversion efficiency of 9.6% to the signal wavelength of ∼430
    Language English
    Publishing date 2020-12-23
    Publishing country United States
    Document type Journal Article
    ISSN 1539-4522
    ISSN (online) 1539-4522
    DOI 10.1364/AO.406237
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Preliminary Estimates of Effectiveness of Monovalent mRNA Vaccines in Preventing Symptomatic SARS-CoV-2 Infection Among Children Aged 3-5 Years - Increasing Community Access to Testing Program, United States, July 2022-February 2023.

    Fleming-Dutra, Katherine E / Ciesla, Allison Avrich / Roper, Lauren E / Smith, Zachary R / Miller, Joseph D / Accorsi, Emma K / Verani, Jennifer R / Shang, Nong / Derado, Gordana / Wiegand, Ryan E / Pilishvili, Tamara / Britton, Amadea / Link-Gelles, Ruth

    MMWR. Morbidity and mortality weekly report

    2023  Volume 72, Issue 7, Page(s) 177–182

    Abstract: On June 18, 2022, the Advisory Committee on Immunization Practices (ACIP) issued interim recommendations for use of the 2-dose monovalent Moderna COVID-19 vaccine as a primary series for children aged 6 months-5 years* and the 3-dose monovalent Pfizer- ... ...

    Abstract On June 18, 2022, the Advisory Committee on Immunization Practices (ACIP) issued interim recommendations for use of the 2-dose monovalent Moderna COVID-19 vaccine as a primary series for children aged 6 months-5 years* and the 3-dose monovalent Pfizer-BioNTech COVID-19 vaccine as a primary series for children aged 6 months-4 years,
    MeSH term(s) Child ; United States/epidemiology ; Humans ; COVID-19/epidemiology ; COVID-19/prevention & control ; SARS-CoV-2 ; BNT162 Vaccine ; COVID-19 Vaccines ; 2019-nCoV Vaccine mRNA-1273 ; COVID-19 Testing ; mRNA Vaccines ; Vaccines, Combined
    Chemical Substances BNT162 Vaccine ; COVID-19 Vaccines ; 2019-nCoV Vaccine mRNA-1273 (EPK39PL4R4) ; mRNA Vaccines ; Vaccines, Combined
    Language English
    Publishing date 2023-02-17
    Publishing country United States
    Document type Journal Article
    ZDB-ID 412775-4
    ISSN 1545-861X ; 0149-2195
    ISSN (online) 1545-861X
    ISSN 0149-2195
    DOI 10.15585/mmwr.mm7207a3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Community-Based Testing Sites for SARS-CoV-2 - United States, March 2020-November 2021.

    Miller, Mark F / Shi, Min / Motsinger-Reif, Alison / Weinberg, Clarice R / Miller, Joseph D / Nichols, Erin

    MMWR. Morbidity and mortality weekly report

    2021  Volume 70, Issue 49, Page(s) 1706–1711

    Abstract: Immediately following the March 13, 2020 declaration of COVID-19 as a national emergency (1), the U.S. government began implementing national testing programs for epidemiologic surveillance, monitoring of frontline workers and populations at higher risk ... ...

    Abstract Immediately following the March 13, 2020 declaration of COVID-19 as a national emergency (1), the U.S. government began implementing national testing programs for epidemiologic surveillance, monitoring of frontline workers and populations at higher risk for acquiring COVID-19, and identifying and allocating limited testing resources. Effective testing supports identification of COVID-19 cases; facilitates isolation, quarantine, and timely treatment measures that limit the spread of SARS-CoV-2 (the virus that causes COVID-19); and guides public health officials about the incidence of COVID-19 in a community. A White House Joint Task Force, co-led by the Department of Health and Human Services (HHS) and the Federal Emergency Management Agency (FEMA), created the Community-Based Testing Sites (CBTS) program working with state and local partners (2). This report describes the timeline, services delivered, and scope of the CBTS program. During March 19, 2020-April 11, 2021, the CBTS program conducted 11,661,923 SARS-CoV-2 tests at 8,319 locations across the United States and its territories, including 402,223 (3.5%) administered through Drive-Through Testing, 10,129,142 (86.9%) through Pharmacies+ Testing, and 1,130,558 (9.7%) through Surge Testing programs. Tests administered through the CBTS program yielded 1,176,959 (10.1%) positive results for SARS-CoV-2. Among tested persons with available race data,* positive test results were highest among American Indian or Alaska Native (14.1%) and Black persons (10.4%) and lowest among White persons (9.9%), Asian persons (7.3%), and Native Hawaiian or Other Pacific Islanders (6.4%). Among persons with reported ethnicity, 25.3% were Hispanic, 15.9% of whom received a positive test result. Overall, 82.0% of test results were returned within 2 days, but the percentage of test results returned within 2 days was as low as 40.7% in July 2020 and 59.3% in December 2020 during peak testing periods. Strong partnerships enabled a rapid coordinated response to establish the federally supported CBTS program to improve access to no-charge diagnostic testing, including for frontline workers, symptomatic persons and close contacts, and persons living in high-prevalence areas. In April 2021, the CBTS Pharmacies+ Testing and Surge Testing programs were expanded into the Increasing Community Access to Testing (ICATT) program. As of November 12, 2021, the CBTS and ICATT programs conducted approximately 26.6 million tests with approximately 10,000 active testing sites. Although the CBTS program represented a relatively small portion of overall U.S. SARS-CoV-2 testing, with its successful partnerships and adaptability, the CBTS program serves as a model to guide current community-based screening, surveillance, and disease control programs, and responses to future public health emergencies.
    MeSH term(s) Adult ; Aged ; Aged, 80 and over ; COVID-19/diagnosis ; COVID-19/epidemiology ; COVID-19 Testing/statistics & numerical data ; Community Health Services/organization & administration ; Cooperative Behavior ; Female ; Health Services Accessibility ; Health Services Needs and Demand ; Humans ; Interinstitutional Relations ; Male ; Medically Underserved Area ; Middle Aged ; Program Evaluation ; United States/epidemiology ; Young Adult
    Language English
    Publishing date 2021-12-10
    Publishing country United States
    Document type Journal Article
    ZDB-ID 412775-4
    ISSN 1545-861X ; 0149-2195
    ISSN (online) 1545-861X
    ISSN 0149-2195
    DOI 10.15585/mmwr.mm7049a3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Practical Guidance to Implementing Quality Management Systems in Public Health Laboratories Performing Next-Generation Sequencing: Personnel, Equipment, and Process Management (Phase 1).

    Hutchins, Rebecca J / Phan, Kristy L / Saboor, Adeeba / Miller, Joseph D / Muehlenbachs, Atis

    Journal of clinical microbiology

    2019  Volume 57, Issue 8

    Abstract: Quality standards as part of an effective quality management system (QMS) are the cornerstone for generating high-quality test results. Next-generation sequencing (NGS) has the potential to improve both clinical diagnostics and public health surveillance ...

    Abstract Quality standards as part of an effective quality management system (QMS) are the cornerstone for generating high-quality test results. Next-generation sequencing (NGS) has the potential to improve both clinical diagnostics and public health surveillance efforts in multiple areas, including infectious diseases. However, the laboratories adopting NGS methods face significant challenges due to the complex and modular process design. This document summarizes the first phase of quality system guidance developed by the Centers for Disease Control and Prevention (CDC) NGS Quality Workgroup. The quality system essentials of personnel, equipment, and process management (quality control and validation) were prioritized based on a risk assessment using information gathered from participating CDC laboratories. Here, we present a prioritized QMS framework, including procedures and documentation tools, to assist laboratory implementation and maintenance of quality practices for NGS workflows.
    MeSH term(s) Clinical Laboratory Techniques/methods ; Clinical Laboratory Techniques/standards ; Guidelines as Topic ; High-Throughput Nucleotide Sequencing/instrumentation ; High-Throughput Nucleotide Sequencing/methods ; High-Throughput Nucleotide Sequencing/standards ; Humans ; Laboratories/standards ; Molecular Diagnostic Techniques/instrumentation ; Molecular Diagnostic Techniques/standards ; Public Health/methods ; Public Health/standards ; Quality Assurance, Health Care/organization & administration ; Quality Assurance, Health Care/standards ; Surveys and Questionnaires ; Workflow
    Language English
    Publishing date 2019-07-26
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 390499-4
    ISSN 1098-660X ; 0095-1137
    ISSN (online) 1098-660X
    ISSN 0095-1137
    DOI 10.1128/JCM.00261-19
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Spatially localized, see-through-wall temperature measurements in a flow reactor using radar REMPI.

    Wu, Yue / Gragston, Mark / Zhang, Zhili / Miller, Joseph D

    Optics letters

    2017  Volume 42, Issue 1, Page(s) 53–56

    Abstract: See-through-wall coherent microwave scattering from resonance-enhanced multiphoton ionization (REMPI) for rotational temperature measurements of molecular oxygen has been developed and demonstrated in a flow reactor at atmospheric pressure. Through ... ...

    Abstract See-through-wall coherent microwave scattering from resonance-enhanced multiphoton ionization (REMPI) for rotational temperature measurements of molecular oxygen has been developed and demonstrated in a flow reactor at atmospheric pressure. Through limited, single-ended optical access, a laser beam was focused to generate local ionization of molecular oxygen in a heated quartz flow reactor enclosed by ceramic heating elements. Coherent microwaves were transmitted, and the subsequent scattering off the laser-induced plasma was received, through the optically opaque ceramic heater walls and used to acquire rotational spectra of molecular oxygen and to determine temperature. Both axial and radial air-temperature profiles were obtained in the flow reactor with an accuracy of ±20  K⁢(±5%). The experimental results show good agreement with a steady-state computational heat transfer model. This technique shows great potential for non-invasive, high-fidelity measurement of spatially localized temperature and radical species concentration in combustion kinetic experiments and confined combustors constructed of advanced ceramic materials in which limited or non-existing optical access hinders usage of conventional optical diagnostic techniques to quantify thermal non-uniformity.
    Language English
    Publishing date 2017-01-01
    Publishing country United States
    Document type Journal Article
    ISSN 1539-4794
    ISSN (online) 1539-4794
    DOI 10.1364/OL.42.000053
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Early Estimates of Bivalent mRNA Booster Dose Vaccine Effectiveness in Preventing Symptomatic SARS-CoV-2 Infection Attributable to Omicron BA.5- and XBB/XBB.1.5-Related Sublineages Among Immunocompetent Adults - Increasing Community Access to Testing Program, United States, December 2022-January 2023.

    Link-Gelles, Ruth / Ciesla, Allison Avrich / Roper, Lauren E / Scobie, Heather M / Ali, Akilah R / Miller, Joseph D / Wiegand, Ryan E / Accorsi, Emma K / Verani, Jennifer R / Shang, Nong / Derado, Gordana / Britton, Amadea / Smith, Zachary R / Fleming-Dutra, Katherine E

    MMWR. Morbidity and mortality weekly report

    2023  Volume 72, Issue 5, Page(s) 119–124

    Abstract: The SARS-CoV-2 Omicron sublineage XBB was first detected in the United States in August 2022.* XBB together with a sublineage, XBB.1.5, accounted for >50% of sequenced lineages in the Northeast by December 31, 2022, and 52% of sequenced lineages ... ...

    Abstract The SARS-CoV-2 Omicron sublineage XBB was first detected in the United States in August 2022.* XBB together with a sublineage, XBB.1.5, accounted for >50% of sequenced lineages in the Northeast by December 31, 2022, and 52% of sequenced lineages nationwide as of January 21, 2023. COVID-19 vaccine effectiveness (VE) can vary by SARS-CoV-2 variant; reduced VE has been observed against some variants, although this is dependent on the health outcome of interest. The goal of the U.S. COVID-19 vaccination program is to prevent severe disease, including hospitalization and death (1); however, VE against symptomatic infection can provide useful insight into vaccine protection against emerging variants in advance of VE estimates against more severe disease. Data from the Increasing Community Access to Testing (ICATT) national pharmacy program for SARS-CoV-2 testing were analyzed to estimate VE of updated (bivalent) mRNA COVID-19 vaccines against symptomatic infection caused by BA.5-related and XBB/XBB.1.5-related sublineages among immunocompetent adults during December 1, 2022–January 13, 2023. Reduction or failure of spike gene (S-gene) amplification (SGTF) in real-time reverse transcription–polymerase chain reaction (RT-PCR) was used as a proxy indicator of infection with likely BA.5-related sublineages and S-gene target presence (SGTP) of infection with likely XBB/XBB.1.5-related sublineages (2). Among 29,175 nucleic acid amplification tests (NAATs) with SGTF or SGTP results available from adults who had previously received 2–4 monovalent COVID-19 vaccine doses, the relative VE of a bivalent booster dose given 2–3 months earlier compared with no bivalent booster in persons aged 18–49 years was 52% against symptomatic BA.5 infection and 48% against symptomatic XBB/XBB.1.5 infection. As new SARS-CoV-2 variants emerge, continued vaccine effectiveness monitoring is important. Bivalent vaccines appear to provide additional protection against symptomatic BA.5-related sublineage and XBB/XBB.1.5-related sublineage infections in persons who had previously received 2, 3, or 4 monovalent vaccine doses. All persons should stay up to date with recommended COVID-19 vaccines, including receiving a bivalent booster dose when they are eligible.
    MeSH term(s) Adult ; United States/epidemiology ; Humans ; COVID-19/epidemiology ; COVID-19/prevention & control ; COVID-19 Vaccines ; SARS-CoV-2/genetics ; Vaccines, Combined ; COVID-19 Testing ; Vaccine Efficacy ; RNA, Messenger
    Chemical Substances COVID-19 Vaccines ; Vaccines, Combined ; RNA, Messenger
    Language English
    Publishing date 2023-02-03
    Publishing country United States
    Document type Journal Article
    ZDB-ID 412775-4
    ISSN 1545-861X ; 0149-2195
    ISSN (online) 1545-861X
    ISSN 0149-2195
    DOI 10.15585/mmwr.mm7205e1
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Effectiveness of Bivalent mRNA Vaccines in Preventing Symptomatic SARS-CoV-2 Infection - Increasing Community Access to Testing Program, United States, September-November 2022.

    Link-Gelles, Ruth / Ciesla, Allison Avrich / Fleming-Dutra, Katherine E / Smith, Zachary R / Britton, Amadea / Wiegand, Ryan E / Miller, Joseph D / Accorsi, Emma K / Schrag, Stephanie J / Verani, Jennifer R / Shang, Nong / Derado, Gordana / Pilishvili, Tamara

    MMWR. Morbidity and mortality weekly report

    2022  Volume 71, Issue 48, Page(s) 1526–1530

    Abstract: On September 1, 2022, bivalent COVID-19 mRNA vaccines, composed of components from the SARS-CoV-2 ancestral and Omicron BA.4/BA.5 strains, were recommended by the Advisory Committee on Immunization Practices (ACIP) to address reduced effectiveness of ... ...

    Abstract On September 1, 2022, bivalent COVID-19 mRNA vaccines, composed of components from the SARS-CoV-2 ancestral and Omicron BA.4/BA.5 strains, were recommended by the Advisory Committee on Immunization Practices (ACIP) to address reduced effectiveness of COVID-19 monovalent vaccines during SARS-CoV-2 Omicron variant predominance (1). Initial recommendations included persons aged ≥12 years (Pfizer-BioNTech) and ≥18 years (Moderna) who had completed at least a primary series of any Food and Drug Administration-authorized or -approved monovalent vaccine ≥2 months earlier (1). On October 12, 2022, the recommendation was expanded to include children aged 5-11 years. At the time of recommendation, immunogenicity data were available from clinical trials of bivalent vaccines composed of ancestral and Omicron BA.1 strains; however, no clinical efficacy data were available. In this study, effectiveness of the bivalent (Omicron BA.4/BA.5-containing) booster formulation against symptomatic SARS-CoV-2 infection was examined using data from the Increasing Community Access to Testing (ICATT) national SARS-CoV-2 testing program.* During September 14-November 11, 2022, a total of 360,626 nucleic acid amplification tests (NAATs) performed at 9,995 retail pharmacies for adults aged ≥18 years, who reported symptoms consistent with COVID-19 at the time of testing and no immunocompromising conditions, were included in the analysis. Relative vaccine effectiveness (rVE) of a bivalent booster dose compared with that of ≥2 monovalent vaccine doses among persons for whom 2-3 months and ≥8 months had elapsed since last monovalent dose was 30% and 56% among persons aged 18-49 years, 31% and 48% among persons aged 50-64 years, and 28% and 43% among persons aged ≥65 years, respectively. Bivalent mRNA booster doses provide additional protection against symptomatic SARS-CoV-2 in immunocompetent persons who previously received monovalent vaccine only, with relative benefits increasing with time since receipt of the most recent monovalent vaccine dose. Staying up to date with COVID-19 vaccination, including getting a bivalent booster dose when eligible, is critical to maximizing protection against COVID-19 (1).
    MeSH term(s) Adolescent ; Adult ; Child ; Humans ; COVID-19/epidemiology ; COVID-19/prevention & control ; COVID-19 Testing ; COVID-19 Vaccines ; mRNA Vaccines ; RNA, Messenger ; SARS-CoV-2 ; United States/epidemiology ; Vaccines, Combined
    Chemical Substances COVID-19 Vaccines ; mRNA Vaccines ; RNA, Messenger ; Vaccines, Combined
    Language English
    Publishing date 2022-12-02
    Publishing country United States
    Document type Journal Article
    ZDB-ID 412775-4
    ISSN 1545-861X ; 0149-2195
    ISSN (online) 1545-861X
    ISSN 0149-2195
    DOI 10.15585/mmwr.mm7148e1
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Dual-pump vibrational/rotational femtosecond/picosecond coherent anti-Stokes Raman scattering temperature and species measurements.

    Dedic, Chloe E / Miller, Joseph D / Meyer, Terrence R

    Optics letters

    2014  Volume 39, Issue 23, Page(s) 6608–6611

    Abstract: A method for simultaneous ro-vibrational and pure-rotational hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps CARS) is presented for multi-species detection and improved temperature sensitivity from room temperature to flame ... ...

    Abstract A method for simultaneous ro-vibrational and pure-rotational hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps CARS) is presented for multi-species detection and improved temperature sensitivity from room temperature to flame conditions. N₂/CH₄ vibrational and N₂/O₂/H₂ rotational Raman coherences are excited simultaneously using fs pump pulses at 660 and 798 nm, respectively, and a common fs Stokes pulse at 798 nm. A fourth narrowband 798 nm ps pulse probes all coherence states at a time delay that minimizes nonresonant background and the effects of collisions. The transition strength is concentration dependent, while the distribution among observed transitions is related to temperature through the Boltzmann distribution. The broadband excitation pulses and multiplexed signal are demonstrated for accurate thermometry from 298 to 2400 K and concentration measurements of four key combustion species.
    Language English
    Publishing date 2014-12-01
    Publishing country United States
    Document type Journal Article
    ISSN 1539-4794
    ISSN (online) 1539-4794
    DOI 10.1364/OL.39.006608
    Database MEDical Literature Analysis and Retrieval System OnLINE

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