56 research outputs found

    Comprehensive quantification of height dependence of entrainment mixing between stratiform cloud top and environment

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    Different entrainment-mixing processes of turbulence are crucial to processes related to clouds; however, only a few qualitative studies have been concentrated on the vertical distributions of entrainment-mixing mechanisms with low vertical resolutions. To quantitatively study vertical profiles of entrainment-mixing mechanisms with a high resolution, the stratiform clouds observed in the Physics of Stratocumulus Top (POST) project are examined. The unique sawtooth flight pattern allows for an examination of the vertical distributions of entrainment-mixing mechanisms with a 5ĝ€¯m vertical resolution. Relative standard deviation of volume mean radius divided by relative standard deviation of liquid water content is introduced to be a new estimation of microphysical homogeneous mixing degree, to overcome difficulties of determining the adiabatic microphysical properties required in existing measures. The vertical profile of this new measure indicates that entrainment-mixing mechanisms become more homogeneous with decreasing altitudes and are consistent with the dynamical measures of Damköhler number and transition scale number. Further analysis shows that the vertical variation of entrainment-mixing mechanisms with decreasing altitudes is due to the increases of turbulent dissipation rate in cloud and relative humidity in droplet-free air and the decrease of size of droplet-free air. The results offer insights into the theoretical understanding and parameterizations of vertical variation of entrainment-mixing mechanisms

    Observations of marine stratocumulus microphysics and implications for processes controlling droplet spectra: Results from the Marine Stratus/Stratocumulus Experiment

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    Journal of Geophysical Research, Vol. 114, D18210The article of record as published may be located at http://dx.doi.org/10.1029/2008JD011035This research was sponsored by the Atmospheric Science Program within the Office of Biological and Environmental Research of U.S. Department of Energy under contract DE-AC02-98CH10886

    Mini-Open Anterior Lumbar Interbody Fusion Combined with Lateral Lumbar Interbody Fusion in Corrective Surgery for Adult Spinal Deformity

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    Study DesignProspective observational study.PurposeTo introduce the techniques and present the surgical outcomes of mini-open anterior lumbar interbody fusion (ALIF) at the most caudal segments of the spine combined with lateral lumbar interbody fusion (LLIF) for the correction of adult spinal deformityOverview of LiteratureAlthough LLIF is increasingly used to correct adult spinal deformity, the correction of sagittal plane deformity with LLIF alone is reportedly suboptimal.MethodsThirty-two consecutive patients with adult spinal deformity underwent LLIF combined with mini-open ALIF at the L5–S1 or L4–S1 levels followed by 2-stage posterior fixation. ALIF was performed for a mean 1.3 levels and LLIF for a mean 2.7 levels. Then, percutaneous fixation was performed in 11 patients (percutaneous group), open correction with facetectomy with or without laminectomy in 16 (open group), and additional pedicle subtraction osteotomy (PSO) in 5 (PSO group). Spinopelvic parameters were compared preoperatively and postoperatively. Hospitalization data and clinical outcomes were recorded.ResultsNo major medical complications developed, and clinical outcomes improved postoperatively in all groups. The mean postoperative segmental lordosis was greater after ALIF (17.5°±5.5°) than after LLIF (8.1°±5.3°, p <0.001). Four patients (12.5%) had lumbar lordosis with a pelvic incidence of ±9° preoperatively, whereas this outcome was achieved postoperatively in 30 patients (93.8%). The total increase in lumbar lordosis was 14.7° in the percutaneous group, 35.3° in the open group, and 57.0° in the PSO group. The ranges of potential lumbar lordosis increase were estimated as 4°–25°, 23°–42°, and 45°–65°, respectively.ConclusionsMini-open ALIF combined with LLIF followed by posterior fixation may be a feasible technique for achieving optimal sagittal balance and reducing the necessity of more extensive surgery

    The Korea–United States Air Quality (KORUS-AQ) field study

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    The Korea–United States Air Quality (KORUS-AQ) field study was conducted during May–June 2016. The effort was jointly sponsored by the National Institute of Environmental Research of South Korea and the National Aeronautics and Space Administration of the United States. KORUS-AQ offered an unprecedented, multi-perspective view of air quality conditions in South Korea by employing observations from three aircraft, an extensive ground-based network, and three ships along with an array of air quality forecast models. Information gathered during the study is contributing to an improved understanding of the factors controlling air quality in South Korea. The study also provided a valuable test bed for future air quality–observing strategies involving geostationary satellite instruments being launched by both countries to examine air quality throughout the day over Asia and North America. This article presents details on the KORUS-AQ observational assets, study execution, data products, and air quality conditions observed during the study. High-level findings from companion papers in this special issue are also summarized and discussed in relation to the factors controlling fine particle and ozone pollution, current emissions and source apportionment, and expectations for the role of satellite observations in the future. Resulting policy recommendations and advice regarding plans going forward are summarized. These results provide an important update to early feedback previously provided in a Rapid Science Synthesis Report produced for South Korean policy makers in 2017 and form the basis for the Final Science Synthesis Report delivered in 2020

    A Nationwide Survey of Lymphangioleiomyomatosis in Korea: Recent Increase in Newly Diagnosed Patients

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    In 2007, the Korean Interstitial Lung Disease Society had collected clinical data of patients who have diagnosed as Lymphangioleiomyomatosis (LAM) since 1990 through nationwide survey, which showed that LAM patients had increased sharply after 2004. The present study was performed to show the clinical features of Korean patients with LAM, and to establish the reason for the recent increase in the diagnosis. All 63 patients were women and the mean age at diagnosis was 36 yr. The most common presenting symptom was dyspnea and 8 patients had tuberous sclerosis complex. The survival rate at 5 yr after diagnosis was 84%. Compared with patients diagnosed after 2004 (n=34), the patients diagnosed before 2004 (n=29) complained with dyspnea more (P=0.016) and had lower FEV1% predicted (P=0.003), and DLco% predicted (P=0.042). The higher proportion of patients diagnosed after 2004 showed the normal chest radiography, and they were detected by routine chest CT screening (P=0.016). This study showed that clinical features of Korean patients with LAM were not different from those reported elsewhere. It is concluded that the reason for the increase of newly diagnosed patients is the result of increase in detection of the early stage LAM by the widespread use of chest CT screening

    The Efficacy of the COMFORT Scale in Assessing Optimal Sedation in Critically Ill Children Requiring Mechanical Ventilation

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    Sedation is often necessary to optimize care for critically ill children requiring mechanical ventilation. If too light or too deep, however, sedation can cause significant adverse reactions, making it important to assess the degree of sedation and maintain its optimal level. We evaluated the efficacy of the COMFORT scale in assessing optimal sedation in critically ill children requiring mechanical ventilation. We compared 12 month data in 21 patients (intervention group), for whom we used the pediatric intensive care unit (PICU) sedation protocol of Asan Medical Center (Seoul, Korea) and the COMFORT scale to maintain optimal sedation, with the data in 20 patients (control group) assessed before using the sedation protocol and the COMPORT scale. Compared with the control group, the intervention group showed significant decreases in the total usage of sedatives and analgesics, the duration of mechanical ventilation (11.0 days vs. 12.5 days) and PICU stay (15.0 days vs. 19.5 days), and the development of withdrawal symptoms (1 case vs. 7 cases). The total duration of sedation (8.0 days vs. 11.5 days) also tended to decrease. These findings suggest that application of protocol-based sedation with the COMPORT scale may benefit children requiring mechanical ventilation

    Generation of double knockout cattle via CRISPR-Cas9 ribonucleoprotein (RNP) electroporation

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    Background Genome editing has been considered as powerful tool in agricultural fields. However, genome editing progress in cattle has not been fast as in other mammal species, for some disadvantages including long gestational periods, single pregnancy, and high raising cost. Furthermore, technically demanding methods such as microinjection and somatic cell nuclear transfer (SCNT) are needed for gene editing in cattle. In this point of view, electroporation in embryos has been risen as an alternative. Results First, editing efficiency of our electroporation methods were tested for embryos. Presence of mutation on embryo was confirmed by T7E1 assay. With first combination, mutation rates for MSTN and PRNP were 57.6% ± 13.7% and 54.6% ± 13.5%, respectively. In case of MSTN/BLG, mutation rates were 83.9% ± 23.6% for MSTN, 84.5% ± 18.0% for BLG. Afterwards, the double-KO embryos were transferred to surrogates and mutation rate was identified in resultant calves by targeted deep sequencing. Thirteen recipients were transferred for MSTN/PRNP, 4 calves were delivered, and one calf underwent an induction for double KO. Ten surrogates were given double-KO embryos for MSTN/BLG, and four of the six calves that were born had mutations in both genes. Conclusions These data demonstrated that production of genome edited cattle via electroporation of RNP could be effectively applied. Finally, MSTN and PRNP from beef cattle and MSTN and BLG from dairy cattle have been born and they will be valuable resources for future precision breeding.This study was financially supported by the National Research Foundation of Korea (NRF-2021R1A5A1033157 for SRC program: 382 Comparative medicine Disease Research Center; NRF-2021R1F1A105195313), the Research Institute of Veterinary Science, the BK21 Four for Future Veterinary Medicine Leading Education and Research Center, and a Seoul National University (SNU) grant (#550e2020005

    Data Descriptor : Collocated observations of cloud condensation nuclei, particle size distributions, and chemical composition

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    Cloud condensation nuclei (CCN) number concentrations alongside with submicrometer particle number size distributions and particle chemical composition have been measured at atmospheric observatories of the Aerosols, Clouds, and Trace gases Research InfraStructure (ACTRIS) as well as other international sites over multiple years. Here, harmonized data records from 11 observatories are summarized, spanning 98,677 instrument hours for CCN data, 157,880 for particle number size distributions, and 70,817 for chemical composition data. The observatories represent nine different environments, e.g., Arctic, Atlantic, Pacific and Mediterranean maritime, boreal forest, or high alpine atmospheric conditions. This is a unique collection of aerosol particle properties most relevant for studying aerosol-cloud interactions which constitute the largest uncertainty in anthropogenic radiative forcing of the climate. The dataset is appropriate for comprehensive aerosol characterization (e.g., closure studies of CCN), model-measurement intercomparison and satellite retrieval method evaluation, among others. Data have been acquired and processed following international recommendations for quality assurance and have undergone multiple stages of quality assessment.Peer reviewe
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