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Determination of trace gas emissions from sources is critical for understanding and regulating air quality and climate change. Here, we demonstrate a method for rapid quantification of the emission rate of multiple gases from simple and complex sources using a mass-balance approach with a spatially scannable open-path sensor – in this case, an open-path dual-comb spectrometer. The open-path spectrometer measures the total column density of gases between the spectrometer and a retroreflector mounted on an unmanned aerial vehicle (UAV). By measuring slant columns at multiple UAV altitudes downwind of a source (or sink), the total emission rate can be rapidly determined without the need for an atmospheric dispersion model. Here, we demonstrate this technique using controlled releases of CH4 and C2H2. We show an emission rate determination to within 50 % of the known flux with a single 10-minute flight and within 10 % of the known flux after 10 flights. Furthermore, we estimate a detection limit for CH4 emissions to be 0.03 g CH4/s. This detection limit is approximately the same as the emissions from 25 head of beef cattle and is less than the average emissions from a small oil field pneumatic controller. Other gases including CO2, NH3, HDO, ethane, formaldehyde (HCHO), CO, and N2O can be measured by simply changing the dual-comb spectrometer.

Supplementary methods (plasmid construction, mass spectrometry, bioinformatics)

Table S1: Clinicopathologic characteristics of 238 patients with liposarcoma. Table S2: Sources of reagents: antibodies, miRNAs, siRNAs, and inhibitors. Table S3: Primers for MSP, qRT-PCR, and cloning of gene 3'UTR reporters. Table S4: Top 50 differentially expressed miRNAs in DDLS versus normal fat tissues. Table S5: Microarray and SILAC analysis in miRNA-treated liposarcoma cells. Table S6: Identification of miR-193b-targets by integration of transcriptomics, proteomics, and miR-target prediction methods. Table S7: DAVID gene ontology analysis of miR-193b targets.

Well-differentiated and dedifferentiated liposarcomas (WDLS/DDLS) account for approximately 13% of all soft tissue sarcoma in adults and cause substantial morbidity or mortality in the majority of patients. In this study, we evaluated the functions of miRNA (miR-193b) in liposarcoma in vitro and in vivo. Deep RNA sequencing on 93 WDLS, 145 DDLS, and 12 normal fat samples demonstrated that miR-193b was significantly underexpressed in DDLS compared with normal fat. Reintroduction of miR-193b induced apoptosis in liposarcoma cells and promoted adipogenesis in human adipose-derived stem cells (ASC). Integrative transcriptomic and proteomic analysis of miR-193b–target networks identified novel direct targets, including CRK-like proto-oncogene (CRKL) and focal adhesion kinase (FAK). miR-193b was found to regulate FAK–SRC–CRKL signaling through CRKL and FAK. miR-193b also stimulated reactive oxygen species signaling by targeting the antioxidant methionine sulfoxide reductase A to modulate liposarcoma cell survival and ASC differentiation state. Expression of miR-193b in liposarcoma cells was downregulated by promoter methylation, resulting at least in part from increased expression of the DNA methyltransferase DNMT1 in WDLS/DDLS. In vivo, miR-193b mimetics and FAK inhibitor (PF-562271) each inhibited liposarcoma xenograft growth. In summary, miR-193b not only functions as a tumor suppressor in liposarcoma but also promotes adipogenesis in ASC. Furthermore, this study reveals key tyrosine kinase and DNA methylation pathways in liposarcoma, some with immediate implications for therapeutic exploration. Cancer Res; 77(21); 5728–40. ©2017 AACR.

Figure S1, showing that lower miR-193b expression is associated with poor distant recurrence-free survival. Figure S2, showing the effects of miR-193b and miR-365 on liposarcoma cell growth. Figure S3, showing the effects of forced expression of miR-193b on the transcriptome and proteome in liposarcoma cells and selected gene ontology terms enriched among miR-193b targets. Figure S4, showing that CRKL affects cell proliferation, apoptosis, and expression of cell cycle regulators. Figure S5, showing that FAK affects cell proliferation and apoptosis. Figure S6, showing that miR-193b induces loss of mitochondrial membrane potential. Figure S7:, showing that knockdown of MSRA increases ROS levels and protein oxidation. Figure S8, showing hypermethylation of the miR-193b promoter and expression of DNMT1 in liposarcoma. Figure S9, showing the tumor suppressive activity of miR-193b in vivo.

A handheld refractometer (HHR) is a versatile instrument in the chemistry lab or in the workplace. It is also inexpensive enough (

We combine mid-infrared dual-comb spectroscopy with attenuated total reflectance measurements to provide in-situ monitoring of a chemical reaction. The mid-infrared dual-comb spectrometer measures quantitative absorption cross-sections of mesityl oxide and diacetone alcohol in the region of 3300–2700 cm−1 (3.0–3.7 μm). Based on these spectra, the system is then used to monitor the hydration of mesityl oxide to diacetone alcohol from which we extract reaction kinetics values. This work shows the potential of dual comb systems to measure and monitor reactions in the condensed phase.

Open-path dual-comb spectroscopy (DCS) is an emerging technique for long open-path measurements across km-scale paths. It provides both broad spectral coverage over hundreds of wavenumbers with high spectral resolution and negligible instrument lineshape. In this chapter, we discuss the principle of open-path DCS; provide an overview of the necessary technology and analysis techniques; review field applications including near-infrared (NIR) measurements of urban CO2 emissions, CH4 emissions from drilling and agricultural operations, measurements to a unmanned aerial vehicle, and recent measurements of volatile organic compounds in the mid-infrared (MIR); and finally provide an outlook especially on how this technique can move to additional spectral regions beyond the NIR and MIR.

Open-path dual-comb spectroscopy measures multispecies livestock emissions, enabling future field-scale ecological studies., Advances in spectroscopy have the potential to improve our understanding of agricultural processes and associated trace gas emissions. We implement field-deployed, open-path dual-comb spectroscopy (DCS) for precise multispecies emissions estimation from livestock. With broad atmospheric dual-comb spectra, we interrogate upwind and downwind paths from pens containing approximately 300 head of cattle, providing time-resolved concentration enhancements and fluxes of CH4, NH3, CO2, and H2O. The methane fluxes determined from DCS data and fluxes obtained with a colocated closed-path cavity ring-down spectroscopy gas analyzer agree to within 6%. The NH3 concentration retrievals have sensitivity of 10 parts per billion and yield corresponding NH3 fluxes with a statistical precision of 8% and low systematic uncertainty. Open-path DCS offers accurate multispecies agricultural gas flux quantification without external calibration and is easily extended to larger agricultural systems where point-sampling-based approaches are insufficient, presenting opportunities for field-scale biogeochemical studies and ecological monitoring.

The output of a laser frequency comb is composed of 100,000+ perfectly spaced, discrete wavelength elements or comb teeth, that act as a massively parallel set of single frequency (CW) lasers with highly stable, well-known frequencies. In dual-comb spectroscopy, two such frequency combs are interfered on a single detector yielding absorption information for each individual comb tooth. This approach combines the strengths of both cw laser spectroscopy and broadband spectroscopy providing high spectral resolution and broad optical bandwidths, all with a single-mode, high-brightness laser beam and a simple, single photodetector, detection scheme. Here I will touch on the application of this system for open-path measurements of atmospheric trace gases (CH4, CO2, CO, NH3, water, ethane, and N2O) and volatile organic compounds (acetone, isopropanol, propane) with field applications targeting industrial oil and gas monitoring and agriculture.

Open-path measurements of atmospheric gas species over km-scale path lengths are well suited to quantify emissions from sources like oil and gas, forest fires, and industry. is a relatively new technique that combines high-resolution and broad spectral coverage with no instrument lineshape and near perfect frequency calibration. These features have enabled open-path DCS to provide accurate measurements of multiple trace gas species simultaneously in the near-infrared across path lengths ranging from 100 m to several km. However, in order to reach the sensitivity necessary to detect many atmospheric trace constituents, including volatile organic compounds (VOCs), operation in the mid-infrared (or UV/Vis) is required.Here, we show a mid-infrared open-path dual comb spectrometer operating in the 3-4 and 4.5-5 μm spectral regions. We have used this spectrometer to measure methane, ethane, and propane (arising primarily from oil and gas activity) across a 1-km-long path in Boulder, CO for 1 week with an ethane sensitivity of ∼0.1 ppb for a 2-minute time resolution. In addition, we show quantitative measurements of intentionally released acetone and isopropanol with a 1-σ sensitivity of 5.7 ppm·m and 2.4 ppm·m, respectively. In the 4.5-5 μm region, we have used this system to detect N2O, CO, and O3. Finally, we have developed a second-generation instrument in the 3-4 μm region that is more compact and has improved stability. This system was recently deployed in a van at an active oil and gas drilling operation. We present preliminary measurements of methane, ethane, and higher hydrocarbons from this deployment as well as initial efforts at emissions quantification.

We present the first quantitative intercomparison between two open-path dual-comb spectroscopy (DCS) instruments which were operated across adjacent 2 km open-air paths over a 2-week period. We used DCS to measure the atmospheric absorption spectrum in the near infrared from 6023 to 6376 cm−1 (1568 to 1660 nm), corresponding to a 355 cm−1 bandwidth, at 0.0067 cm−1 sample spacing. The measured absorption spectra agree with each other to within 5 × 10−4 in absorbance without any external calibration of either instrument. The absorption spectra are fit to retrieve path-integrated concentrations for carbon dioxide (CO2), methane (CH4), water (H2O), and deuterated water (HDO). The retrieved dry mole fractions agree to 0.14 % (0.57 ppm) for CO2, 0.35 % (7 ppb) for CH4, and 0.40 % (36 ppm) for H2O at ∼ 30 s integration time over the 2-week measurement campaign, which included 24 °C outdoor temperature variations and periods of strong atmospheric turbulence. This agreement is at least an order of magnitude better than conventional active-source open-path instrument intercomparisons and is particularly relevant to future regional flux measurements as it allows accurate comparisons of open-path DCS data across locations and time. We additionally compare the open-path DCS retrievals to a World Meteorological Organization (WMO)-calibrated cavity ring-down point sensor located along the path with good agreement. Short-term and long-term differences between the open-path DCS and point sensor are attributed, respectively, to spatial sampling discrepancies and to inaccuracies in the current spectral database used to fit the DCS data. Finally, the 2-week measurement campaign yields diurnal cycles of CO2 and CH4 that are consistent with the presence of local sources of CO2 and absence of local sources of CH4.

Purpose We conducted a retrospective analysis to assess the safety profile of nivolumab monotherapy in patients with advanced melanoma and describe the management of adverse events (AEs) using established safety guidelines. Patients and Methods Safety data were pooled from four studies, including two phase III trials, with patients who received nivolumab 3 mg/kg once every 2 weeks. We evaluated rate of treatment-related AEs, time to onset and resolution of select AEs (those with potential immunologic etiology), and impact of select AEs and suppressive immune-modulating agents (IMs) on antitumor efficacy. Results Among 576 patients, 71% (95% CI, 67% to 75%) experienced any-grade treatment-related AEs (most commonly fatigue [25%], pruritus [17%], diarrhea [13%], and rash [13%]), and 10% (95% CI, 8% to 13%) experienced grade 3 to 4 treatment-related AEs. No drug-related deaths were reported. Select AEs (occurring in 49% of patients) were most frequently skin related, GI, endocrine, and hepatic; grade 3 to 4 select AEs occurred in 4% of patients. Median time to onset of select AEs ranged from 5 weeks for skin to 15 weeks for renal AEs. Approximately 24% of patients received systemic IMs to manage select AEs, which in most cases resolved. Adjusting for number of doses, objective response rate (ORR) was significantly higher in patients who experienced treatment-related select AEs of any grade compared with those who did not. ORRs were similar in patients who did and patients who did not receive systemic IMs. Conclusion Treatment-related AEs with nivolumab monotherapy were primarily low grade, and most resolved with established safety guidelines. Use of IMs did not affect ORR, although treatment-related select AEs of any grade were associated with higher ORR, but no progression-free survival benefit.

Open-path dual-comb spectroscopy is used to quantify CO2, CH4, H2O and NH3 concentrations adjacent to a cattle feedlot. In all cases except NH3, the data is compared against closed-path cavity ring-down spectroscopy.

Open-path mid-infrared dual-comb spectroscopy is performed over a 2 km- long link with bandwidth spanning the atmospheric transmission window near 4.7 pm. We quantify mixing ratios for CO, CO2, N2O, H2O, and O3. Work of the US Government and not subject to copyright.

We deploy a mid-infrared dual-comb spectrometer in a van for field measurements of volatile organic compounds (VOCs). We also use a similar, laboratory system to measure ambient VOCs over a 2km round-trip path. Work of the US Government and not subject to copyright.

Open-path dual-comb spectroscopy in the 4.5-4.9 pm region is performed over a 300 m- long link to quantify mixing ratios for CO, CO2, N2O, H2O, and O3.

We demonstrate a robust, portable mid-infrared dual-comb spectrometer based on modelocked fiber lasers and difference frequency generation, allowing high resolution, open-path spectroscopy in the 3.1-4 m spectral region. Work of the US Government and not subject to copyright.

We demonstrate a new method for rapid quantification of emissions from point or small area sources via direct flux measurement using open-path dual-comb spectroscopy to a retroflector on a UAV.

We used a MIR dual frequency comb spectroscopy system to measure emissions at a fracking site. We present preliminary measurements of methane, ethane, and higher hydrocarbons. The methane shows good agreement with a co-located point sensor.