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1.
Nature ; 590(7846): 428-432, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33568809

RESUMEN

The atmospheric concentration of trichlorofluoromethane (CFC-11) has been in decline since the production of ozone-depleting substances was phased out under the Montreal Protocol1,2. Since 2013, the concentration decline of CFC-11 slowed unexpectedly owing to increasing emissions, probably from unreported production, which, if sustained, would delay the recovery of the stratospheric ozone layer1-12. Here we report an accelerated decline in the global mean CFC-11 concentration during 2019 and 2020, derived from atmospheric concentration measurements at remote sites around the world. We find that global CFC-11 emissions decreased by 18 ± 6 gigagrams per year (26 ± 9 per cent; one standard deviation) from 2018 to 2019, to a 2019 value (52 ± 10 gigagrams per year) that is similar to the 2008-2012 mean. The decline in global emissions suggests a substantial decrease in unreported CFC-11 production. If the sharp decline in unexpected global emissions and unreported production is sustained, any associated future ozone depletion is likely to be limited, despite an increase in the CFC-11 bank (the amount of CFC-11 produced, but not yet emitted) by 90 to 725 gigagrams by the beginning of 2020.

2.
Nature ; 586(7828): 248-256, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33028999

RESUMEN

Nitrous oxide (N2O), like carbon dioxide, is a long-lived greenhouse gas that accumulates in the atmosphere. Over the past 150 years, increasing atmospheric N2O concentrations have contributed to stratospheric ozone depletion1 and climate change2, with the current rate of increase estimated at 2 per cent per decade. Existing national inventories do not provide a full picture of N2O emissions, owing to their omission of natural sources and limitations in methodology for attributing anthropogenic sources. Here we present a global N2O inventory that incorporates both natural and anthropogenic sources and accounts for the interaction between nitrogen additions and the biochemical processes that control N2O emissions. We use bottom-up (inventory, statistical extrapolation of flux measurements, process-based land and ocean modelling) and top-down (atmospheric inversion) approaches to provide a comprehensive quantification of global N2O sources and sinks resulting from 21 natural and human sectors between 1980 and 2016. Global N2O emissions were 17.0 (minimum-maximum estimates: 12.2-23.5) teragrams of nitrogen per year (bottom-up) and 16.9 (15.9-17.7) teragrams of nitrogen per year (top-down) between 2007 and 2016. Global human-induced emissions, which are dominated by nitrogen additions to croplands, increased by 30% over the past four decades to 7.3 (4.2-11.4) teragrams of nitrogen per year. This increase was mainly responsible for the growth in the atmospheric burden. Our findings point to growing N2O emissions in emerging economies-particularly Brazil, China and India. Analysis of process-based model estimates reveals an emerging N2O-climate feedback resulting from interactions between nitrogen additions and climate change. The recent growth in N2O emissions exceeds some of the highest projected emission scenarios3,4, underscoring the urgency to mitigate N2O emissions.


Asunto(s)
Óxido Nitroso/análisis , Óxido Nitroso/metabolismo , Agricultura , Atmósfera/química , Productos Agrícolas/metabolismo , Actividades Humanas , Internacionalidad , Nitrógeno/análisis , Nitrógeno/metabolismo
3.
Proc Natl Acad Sci U S A ; 118(33)2021 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-34380737

RESUMEN

In the Arctic and Boreal region (ABR) where warming is especially pronounced, the increase of gross primary production (GPP) has been suggested as an important driver for the increase of the atmospheric CO2 seasonal cycle amplitude (SCA). However, the role of GPP relative to changes in ecosystem respiration (ER) remains unclear, largely due to our inability to quantify these gross fluxes on regional scales. Here, we use atmospheric carbonyl sulfide (COS) measurements to provide observation-based estimates of GPP over the North American ABR. Our annual GPP estimate is 3.6 (2.4 to 5.5) PgC · y-1 between 2009 and 2013, the uncertainty of which is smaller than the range of GPP estimated from terrestrial ecosystem models (1.5 to 9.8 PgC · y-1). Our COS-derived monthly GPP shows significant correlations in space and time with satellite-based GPP proxies, solar-induced chlorophyll fluorescence, and near-infrared reflectance of vegetation. Furthermore, the derived monthly GPP displays two different linear relationships with soil temperature in spring versus autumn, whereas the relationship between monthly ER and soil temperature is best described by a single quadratic relationship throughout the year. In spring to midsummer, when GPP is most strongly correlated with soil temperature, our results suggest the warming-induced increases of GPP likely exceeded the increases of ER over the past four decades. In autumn, however, increases of ER were likely greater than GPP due to light limitations on GPP, thereby enhancing autumn net carbon emissions. Both effects have likely contributed to the atmospheric CO2 SCA amplification observed in the ABR.

4.
Clin Psychol Psychother ; 30(3): 491-509, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36511369

RESUMEN

BACKGROUND: Personal recovery literature has been influential in the conceptualization of emotional distress and service provision. While personal recovery in psychosis has been well-studied, voice hearing literature has not been reviewed to elucidate recovery processes. METHOD: Five databases were systematically searched to identify relevant qualitative recovery literature. Twelve eligible studies were included in this review, and an appraisal tool was applied to assess quality. Thematic synthesis was used to examine the results. RESULTS: Three superordinate themes were found relating to 'Recovery Phases', 'Recovery Facilitators' and 'Barriers to Recovery'. Papers included descriptions of finding voices distressing initially yet moving towards integrating and accepting voices. Searching for meaning versus seeking distance from voices were pivotal processes to recovery pathways. Enabling and disrupting recovery experiences are discussed within a proposed model. CONCLUSIONS: Recovery in voice hearing is an individual and potentially ongoing process. Future research should seek to examine recovery factors in voice hearing longitudinally and add further evidence to the supportive role services can play in recovery and voice hearing.


Asunto(s)
Trastornos Psicóticos , Voz , Humanos , Alucinaciones/psicología , Trastornos Psicóticos/psicología , Emociones , Audición
5.
World J Surg Oncol ; 19(1): 118, 2021 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-33853623

RESUMEN

BACKGROUND: The optimal type of operative drainage following pancreaticoduodenectomy (PD) remains unclear. Our objective is to investigate risk associated with closed drainage techniques (passive [gravity] vs. suction) after PD. METHODS: We assessed operative drainage techniques utilized in patients undergoing PD in the ACS-NSQIP pancreas-targeted database from 2016 to 2018. Using multivariable logistic regression to adjust for characteristics of the patient, procedure, and pancreas, we examined the association between use of gravity drainage and postoperative outcomes. RESULTS: We identified 9665 patients with drains following PD from 2016 to 2018, of which 12.7% received gravity drainage. 61.0% had a diagnosis of adenocarcinoma or pancreatitis, 26.5% had a duct <3 mm, and 43.5% had a soft or intermediate gland. After multivariable adjustment, gravity drainage was associated with decreased rates of postoperative pancreatic fistula (odds ratio [OR] 0.779, 95% confidence interval [CI] 0.653-0.930, p=0.006), delayed gastric emptying (OR 0.830, 95% CI 0.693-0.988, p=0.036), superficial SSI (OR 0.741, 95% CI 0.572-0.959, p=0.023), organ space SSI (OR 0.791, 95% CI 0.658-0.951, p=0.012), and readmission (OR 0.807, 95% CI 0.679-0.958, p=0.014) following PD. CONCLUSIONS: Gravity drainage is independently associated with decreased rates of CR-POPF, DGE, SSI, and readmission following PD. Additional prospective research is necessary to better understand the preferred drainage technique following PD.


Asunto(s)
Drenaje , Fístula Pancreática , Humanos , Fístula Pancreática/epidemiología , Fístula Pancreática/etiología , Pancreaticoduodenectomía/efectos adversos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Pronóstico , Estudios Prospectivos , Factores de Riesgo
6.
Cancer Metastasis Rev ; 38(1-2): 223-236, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30618016

RESUMEN

Mucins (MUC) protect epithelial barriers from environmental insult to maintain homeostasis. However, their aberrant overexpression and glycosylation in various malignancies facilitate oncogenic events from inception to metastasis. Mucin-associated sialyl-Tn (sTn) antigens bind to various receptors present on the dendritic cells (DCs), macrophages, and natural killer (NK) cells, resulting in overall immunosuppression by either receptor masking or inhibition of cytolytic activity. MUC1-mediated interaction of tumor cells with innate immune cells hampers cross-presentation of processed antigens on MHC class I molecules. MUC1 and MUC16 bind siglecs and mask Toll-like receptors (TLRs), respectively, on DCs promoting an immature DC phenotype that in turn reduces T cell effector functions. Mucins, such as MUC1, MUC2, MUC4, and MUC16, interact with or form aggregates with neutrophils, macrophages, and platelets, conferring protection to cancer cells during hematological dissemination and facilitate their spread and colonization to the metastatic sites. On the contrary, poor glycosylation of MUC1 and MUC4 at the tandem repeat region (TR) generates cancer-specific immunodominant epitopes. The presence of MUC16 neo-antigen-specific T cell clones and anti-MUC1 antibodies in cancer patients suggests that mucins can serve as potential targets for developing cancer therapeutics. The present review summarizes the molecular events involved in mucin-mediated immunomodulation, and metastasis, as well as the utility of mucins as targets for cancer immunotherapy and radioimmunotherapy.


Asunto(s)
Mucinas/inmunología , Neoplasias/inmunología , Neoplasias/patología , Animales , Humanos , Inmunomodulación , Metástasis de la Neoplasia
7.
Ann Surg ; 271(2): 296-302, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-30188400

RESUMEN

OBJECTIVE: Comparative analyses of survival and funding statistics in cancers with high mortality were performed to quantify discrepancies and identify areas for intervention. BACKGROUND: Discrepancies in research funding may contribute to stagnant survival rates in pancreatic ductal adenocarcinoma (PDAC). METHODS: The Surveillance, Epidemiology, and End Results database was queried for survival statistics. Funding data were obtained from the National Cancer Institute (NCI). Clinical trial data were obtained from www.clinicaltrials.gov. Cancers with high mortality were included for analyses. RESULTS: Since 1997, PDAC has received lesser funding ($1.41 billion) than other cancers such as breast ($10.52 billion), prostate ($4.93 billion), lung ($4.80 billion), and colorectal ($4.50 billion). Similarly, fewer clinical trials have been completed in PDAC (n = 608) compared with breast (n = 1904), lung (n = 1629), colorectal (n = 1080), and prostate (n = 1055) cancer. Despite this, since 1997, dollars invested in PDAC research produced a greater return on investment with regards to 5-year overall survival (5Y-OS) compared with breast, prostate, uterine, and ovarian cancer. Incremental cost-effectiveness analysis demonstrates that millions (liver, non-Hodgkin lymphoma, and melanoma) and billions (colorectal and lung) of dollars were required for each additional 1% increase in 5Y-OS compared with PDAC. Funding of research towards early diagnosis of PDAC has decreased by 19% since 2007. For nearly all cancers, treatment-related research receives the highest percentage of NCI funding. CONCLUSIONS: Funding of PDAC research is significantly less than other cancers, despite its higher mortality and greater potential to improve 5Y-OS. Increased awareness and lobbying are required to increase funding, promote research, and improve survival.


Asunto(s)
Investigación Biomédica/economía , Carcinoma Ductal Pancreático/mortalidad , Carcinoma Ductal Pancreático/cirugía , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/cirugía , Apoyo a la Investigación como Asunto , Adulto , Anciano , Femenino , Neoplasias de los Genitales Femeninos/mortalidad , Neoplasias de los Genitales Femeninos/cirugía , Humanos , Masculino , Persona de Mediana Edad , National Cancer Institute (U.S.) , Neoplasias de la Próstata/mortalidad , Neoplasias de la Próstata/cirugía , Programa de VERF , Análisis de Supervivencia , Estados Unidos , Neoplasias Pancreáticas
8.
J Surg Oncol ; 120(4): 661-669, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31292967

RESUMEN

BACKGROUND: Anastomotic leak is the most common major complication after esophagectomy. We investigated the 2016 American College of Surgeons National Surgical Quality Improvement Program esophagectomy targeted database to identify risk factors for anastomotic leak. METHODS: Patients who underwent esophagectomy for cancer were included. Patients experiencing an anstomotic leak were identified, and univariate and multivariable logistic regression was performed to identify variables independently associated with anastomotic leak. RESULTS: Of 915 patients included, 83% were male and the median age was 64 years. Patients with anastomotic leak more frequently had additional complications (87% vs 36%, P < .001). Rates of reoperation (64% vs 11%, P < .001) and mortality (8% vs 2%, P = .001) were higher in patients with anastomotic leak. After adjusting for patient and procedure characteristics, prolonged operative time (for each additional 30-minutes; adjusted odds ratios (AOR) 1.068, 95% CI, 1.022-1.115, P = .003), increased preoperative WBC count (for each 3000/µL increase; AOR 1.323, 95% CI, 1.048-1.670, P = .019), pre-existing diabetes (AOR 1.601, 95% CI, 1.012-2.534, P = .045), and perioperative transfusion (AOR 1.777, 95% CI, 1.064-2.965, P = .028) were independently associated with anastomotic leak. CONCLUSION: Both patient and procedure-related factors are associated with anastomotic leak. Though frequently non-modifiable, these findings could facilitate risk stratification and early detection of anastomotic leak to reduce associated morbidity.


Asunto(s)
Adenocarcinoma/cirugía , Fuga Anastomótica/etiología , Carcinoma de Células Escamosas/cirugía , Neoplasias Esofágicas/cirugía , Esofagectomía/efectos adversos , Medición de Riesgo/métodos , Adenocarcinoma/patología , Anciano , Fuga Anastomótica/patología , Carcinoma de Células Escamosas/patología , Neoplasias Esofágicas/patología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico
9.
Proc Natl Acad Sci U S A ; 113(11): 2880-5, 2016 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-26929368

RESUMEN

National-scale emissions of carbon tetrachloride (CCl4) are derived based on inverse modeling of atmospheric observations at multiple sites across the United States from the National Oceanic and Atmospheric Administration's flask air sampling network. We estimate an annual average US emission of 4.0 (2.0-6.5) Gg CCl4 y(-1) during 2008-2012, which is almost two orders of magnitude larger than reported to the US Environmental Protection Agency (EPA) Toxics Release Inventory (TRI) (mean of 0.06 Gg y(-1)) but only 8% (3-22%) of global CCl4 emissions during these years. Emissive regions identified by the observations and consistently shown in all inversion results include the Gulf Coast states, the San Francisco Bay Area in California, and the Denver area in Colorado. Both the observation-derived emissions and the US EPA TRI identified Texas and Louisiana as the largest contributors, accounting for one- to two-thirds of the US national total CCl4 emission during 2008-2012. These results are qualitatively consistent with multiple aircraft and ship surveys conducted in earlier years, which suggested significant enhancements in atmospheric mole fractions measured near Houston and surrounding areas. Furthermore, the emission distribution derived for CCl4 throughout the United States is more consistent with the distribution of industrial activities included in the TRI than with the distribution of other potential CCl4 sources such as uncapped landfills or activities related to population density (e.g., use of chlorine-containing bleach).

10.
J Craniofac Surg ; 30(7): 2014-2017, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31449228

RESUMEN

BACKGROUND: Bleeding is the most common adverse event in patients undergoing cranial vault reconstruction. The authors compare the transfusion rates against a national sample to determine whether the patients experience lower transfusion rates. METHODS: The authors queried the Pediatric National Surgical Quality Improvement Program (Peds-NSQIP) for patients who underwent cranial vault reconstruction (CPT 61559) and compared them to patients who underwent cranial vault reconstruction for sagittal craniosynostosis at Children's Hospital and Medical Center (CHMC) in Omaha, Nebraska. Patients over the age of 24 months were excluded. Binary logistic regression analysis was performed using IBM-SPSS v24.0 to determine factors associated with transfusion at CHMC. RESULTS: Patient demographics, preoperative hematocrit and platelet counts, readmission rates, and reoperation rates did not differ between CHMC (N = 54) and Peds-NSQIP (N = 1320) cohorts. Patients in the CHMC cohort had shorter preincision anesthesia times (47 versus 80 minutes, P < 0.001), shorter operative times (108 versus 175 minutes, P < 0.001), lower transfusion rates (50% versus 73%, P < 0.001), and smaller mean transfusion volumes (16 versus 33 mL/kg, P < 0.001); however mean length of stay was longer (4.1 versus 3.6 days, P < 0.001). Factors independently associated with transfusion at CHMC included preoperative hematocrit (odds ratio [OR] 0.423, P = 0.002), administration of an antifibrinolytic agent (OR 0.004, P = 0.001) and temperature at the time of incision (OR 0.020, P = 0.043). CONCLUSION: Patients at CHMC require less transfused blood and experience low transfusion rates. Preoperative hematocrit, administration of antifibrinolytic agents, and temperature at the time of incision are all modifiable factors associated with perioperative transfusion.


Asunto(s)
Transfusión Sanguínea , Cráneo/cirugía , Antifibrinolíticos/uso terapéutico , Pérdida de Sangre Quirúrgica , Preescolar , Estudios de Cohortes , Craneosinostosis/cirugía , Femenino , Hematócrito , Humanos , Lactante , Masculino , Tempo Operativo , Atención Perioperativa , Procedimientos de Cirugía Plástica , Reoperación
12.
J Biol Chem ; 291(7): 3411-22, 2016 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-26677217

RESUMEN

Bunyaviruses are considered to be emerging pathogens facilitated by the segmented nature of their genome that allows reassortment between different species to generate novel viruses with altered pathogenicity. Bunyaviruses are transmitted via a diverse range of arthropod vectors, as well as rodents, and have established a global disease range with massive importance in healthcare, animal welfare, and economics. There are no vaccines or anti-viral therapies available to treat human bunyavirus infections and so development of new anti-viral strategies is urgently required. Bunyamwera virus (BUNV; genus Orthobunyavirus) is the model bunyavirus, sharing aspects of its molecular and cellular biology with all Bunyaviridae family members. Here, we show for the first time that BUNV activates and requires cellular potassium (K(+)) channels to infect cells. Time of addition assays using K(+) channel modulating agents demonstrated that K(+) channel function is critical to events shortly after virus entry but prior to viral RNA synthesis/replication. A similar K(+) channel dependence was identified for other bunyaviruses namely Schmallenberg virus (Orthobunyavirus) as well as the more distantly related Hazara virus (Nairovirus). Using a rational pharmacological screening regimen, two-pore domain K(+) channels (K2P) were identified as the K(+) channel family mediating BUNV K(+) channel dependence. As several K2P channel modulators are currently in clinical use, our work suggests they may represent a new and safe drug class for the treatment of potentially lethal bunyavirus disease.


Asunto(s)
Antivirales/farmacología , Virus Bunyamwera/efectos de los fármacos , Infecciones por Bunyaviridae/tratamiento farmacológico , Interacciones Huésped-Patógeno/efectos de los fármacos , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio de Dominio Poro en Tándem/antagonistas & inhibidores , Integración Viral/efectos de los fármacos , Aedes , Animales , Virus Bunyamwera/crecimiento & desarrollo , Virus Bunyamwera/fisiología , Infecciones por Bunyaviridae/metabolismo , Infecciones por Bunyaviridae/virología , Línea Celular , Chlorocebus aethiops , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Humanos , Mesocricetus , Nairovirus/efectos de los fármacos , Nairovirus/crecimiento & desarrollo , Nairovirus/fisiología , Orthobunyavirus/efectos de los fármacos , Orthobunyavirus/crecimiento & desarrollo , Orthobunyavirus/fisiología , Canales de Potasio de Dominio Poro en Tándem/genética , Canales de Potasio de Dominio Poro en Tándem/metabolismo , Células Vero
13.
Anal Chem ; 89(22): 12068-12075, 2017 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-29027457

RESUMEN

In this study, standard gas mixtures of SF6 in synthetic air were gravimetrically developed as a suite consisting of 6 mixtures with mole fractions of SF6 ranging from 5 to 15 pmol/mol. For precision in weighing the gas fills, an automatic weighing system coupled with a high sensitivity mass balance was used and a gravimetry precision of 3 mg (2σ) was achieved. Impurity profiles of the raw gases were determined by various analyzers. In particular, sub pmol/mol levels of SF6 in the matrix components (N2, O2, and Ar) were carefully measured, since the mole fraction of SF6 in the final step can be significantly biased by this trace amount of SF6 in the raw gases of the matrix components. Gravimetric dilution of SF6 by purity-assessed N2 was performed in 6 steps to achieve a mole fraction of 440 pmol/mol. In the final step, O2 and Ar were added to mimic the atmospheric composition. Gravimetric fractions of SF6 and the associated standard uncertainty in each step were computed according to the ISO 6142 and JCGM 100:2008, respectively, and validated experimentally. Eventually, the SF6 fraction uncertainty of the standard gas mixtures combined by uncertainties of gravimetric preparation and verification measurements were found to be nominally 0.08% at a 95% confidence interval. A comparison with independent calibration standards from NOAA shows agreement within 0.49%, satisfying the extended WMO compatibility goal, 0.05 ppt.

14.
Nucleic Acids Res ; 43(15): 7480-8, 2015 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-26209133

RESUMEN

On average, mutations are deleterious to proteins. Mutations conferring new function to a protein often come at the expense of protein folding or stability, reducing overall activity. Over the years, a panel of T7 RNA polymerases have been designed or evolved to accept nucleotides with modified ribose moieties. These modified RNAs have proven useful, especially in vivo, but the transcriptional yields tend to be quite low. Here we show that mutations previously shown to increase the thermal tolerance of T7 RNA polymerase can increase the activity of mutants with expanded substrate range. The resulting polymerase mutants can be used to generate 2'-O-methyl modified RNA with yields much higher than enzymes currently employed.


Asunto(s)
ARN Polimerasas Dirigidas por ADN/genética , Mutación , Transcripción Genética , Proteínas Virales/genética , ARN Polimerasas Dirigidas por ADN/química , ARN Polimerasas Dirigidas por ADN/metabolismo , Estabilidad de Enzimas/genética , ARN/biosíntesis , ARN/química , Especificidad por Sustrato , Temperatura , Proteínas Virales/química , Proteínas Virales/metabolismo
15.
Anal Chem ; 88(6): 3376-85, 2016 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-26890890

RESUMEN

The National Institute of Standards and Technology (NIST) recently began to develop standard mixtures of greenhouse gases as part of a broad program mandated by the 2009 United States Congress to support research in climate change. To this end, NIST developed suites of gravimetrically assigned primary standard mixtures (PSMs) comprising carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in a dry-natural air balance at ambient mole fraction levels. In parallel, the National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado, charged 30 aluminum gas cylinders with northern hemisphere air at Niwot Ridge, Colorado. These mixtures, which constitute NIST Standard Reference Material (SRM) 1720 Northern Continental Air, were certified by NIST for ambient mole fractions of CO2, CH4, and N2O relative to NIST PSMs. NOAA-assigned values are also provided as information in support of the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) Program for CO2, CH4, and N2O, since NOAA serves as the WMO Central Calibration Laboratory (CCL) for CO2, CH4, and N2O. Relative expanded uncertainties at the 95% confidence interval are <±0.06% of the certified values for CO2 and N2O and <0.2% for CH4, which represents the smallest relative uncertainties specified to date for a gaseous SRM produced by NIST. Agreement between the NOAA (WMO/GAW) and NIST values based on their respective calibration standards suites is within 0.05%, 0.13%, and 0.06% for CO2, CH4, and N2O, respectively. This collaborative development effort also represents the first of its kind for a gaseous SRM developed by NIST.

16.
Anal Chem ; 86(5): 2580-9, 2014 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-24555659

RESUMEN

Studies of climate change increasingly recognize the diverse influences of hydrocarbons in the atmosphere, including roles in particulates and ozone formation. Measurements of key nonmethane hydrocarbons (NMHCs) suggest atmospheric mole fractions ranging from low picomoles per mol (ppt) to nanomoles per mol (ppb), depending on location and compound. To accurately establish mole fraction trends and to relate measurement records from many laboratories and researchers, it is essential to have accurate, stable, calibration standards. In February of 2008, the National Institute of Standards and Technology (NIST) developed and reported on picomoles per mol standards containing 18 nonmethane hydrocarbon compounds covering the mole fraction range of 60 picomoles per mol to 230 picomoles per mol. The stability of these gas mixtures was only characterized over a short time period (2 to 3 months). NIST recently prepared a suite of primary standard gas mixtures by gravimetric dilution to ascertain the stability of the 2008 picomoles per mol NMHC standards suite. The data from this recent chromatographic intercomparison of the 2008 to the 2011 suites confirm a much longer stability of almost 5 years for 15 of the 18 hydrocarbons; the double-bonded alkenes of propene, isobutene, and 1-pentene showed instability, in line with previous publications. The agreement between the gravimetric values from preparation and the analytical mole fractions determined from regression illustrate the internal consistency of the suite within ±2 pmol/mol. However, results for several of the compounds reflect stability problems for the three double-bonded hydrocarbons. An international intercomparison on one of the 2008 standards has also been completed. Participants included National Metrology Institutes, United States government laboratories, and academic laboratories. In general, results for this intercomparison agree to within about ±5% with the gravimetric mole fractions of the hydrocarbons.

17.
Front Pharmacol ; 15: 1377132, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38783934

RESUMEN

The University of Florida Health Precision Medicine Program plays a crucial role in delivering pharmacogenomics (PGx) result notes to providers who request PGx testing. Despite this, there is currently a lack of a formal assessment of provider needs and established best practice design principles to guide the ongoing development of PGx result notes. This study aims to enhance the content and format of the PGx consult note at UF Health by incorporating valuable feedback from healthcare providers. Through in-depth user sessions involving 11 participants, we evaluated the usability of our consult note template. While overall satisfaction with the content was noted, specific sections, including those addressing phenoconversion and the medication list, were identified for revision to enhance clarity based on insightful provider feedback.

18.
Arch Pathol Lab Med ; 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38190268

RESUMEN

CONTEXT.­: Existing targeted cystic fibrosis screening assays miss important pathogenic CFTR variants in the ethnically diverse US population. OBJECTIVE.­: To evaluate the analytic performance of a multiplex polymerase chain reaction (PCR)/capillary electrophoresis (CE) CFTR assay panel that simultaneously interrogates primary pathogenic variants of different ethnic/ancestral groups. DESIGN.­: Performance characteristic assessment and variant coverage comparison of the panel with a focus on ethnicity-specific CFTR variants were performed. Sample DNA was primarily from whole blood or cell lines. Detection of CFTR carriers was compared across several commercially available CFTR kits and recommended variant sets based on panel content. RESULTS.­: The panel interrogated 65 pathogenic CFTR variants representing 92% coverage from a recent genomic sequencing survey of the US population, including 4 variants with top 5 frequency in African or Asian populations not reflected in other targeted panels. In simulation studies, the panel represented 95% of carriers across the global population, resulting in 6.9% to 19.0% higher carrier detection rate compared with 10 targeted panels or variant sets. Precision and sensitivity/specificity were 100% concordant. Multisite sample-level genotyping accuracy was 99.2%. Across PCR and CE instruments, sample-level genotyping accuracy was 97.1%, with greater than 99% agreement for all variant-level metrics. CONCLUSIONS.­: The CFTR assay achieves 92% or higher coverage of CFTR variants in diverse populations and provides improved pan-ethnic coverage of minority subgroups of the US populace. The assay can be completed within 5 hours from DNA sample to genotype, and performance data exceed acceptance criteria for analytic metrics. This assay panel content may help address gaps in ancestry-specific CFTR genotypes while providing a streamlined procedure with rapidly generated results.

19.
J Phys Chem A ; 117(43): 11049-65, 2013 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-24079521

RESUMEN

The atmospheric processing of (E)- and (Z)-1,2-dichlorohexafluoro-cyclobutane (1,2-c-C4F6Cl2, R-316c) was examined in this work as the ozone depleting (ODP) and global warming (GWP) potentials of this proposed replacement compound are presently unknown. The predominant atmospheric loss processes and infrared absorption spectra of the R-316c isomers were measured to provide a basis to evaluate their atmospheric lifetimes and, thus, ODPs and GWPs. UV absorption spectra were measured between 184.95 to 230 nm at temperatures between 214 and 296 K and a parametrization for use in atmospheric modeling is presented. The Cl atom quantum yield in the 193 nm photolysis of R-316c was measured to be 1.90 ± 0.27. Hexafluorocyclobutene (c-C4F6) was determined to be a photolysis co-product with molar yields of 0.7 and 1.0 (±10%) for (E)- and (Z)-R-316c, respectively. The 296 K total rate coefficient for the O((1)D) + R-316c reaction, i.e., O((1)D) loss, was measured to be (1.56 ± 0.11) × 10(-10) cm(3) molecule(-1) s(-1) and the reactive rate coefficient, i.e., R-316c loss, was measured to be (1.36 ± 0.20) × 10(-10) cm(3) molecule(-1) s(-1) corresponding to a ~88% reactive yield. Rate coefficient upper-limits for the OH and O3 reaction with R-316c were determined to be <2.3 × 10(-17) and <2.0 × 10(-22) cm(3) molecule(-1) s(-1), respectively, at 296 K. The quoted uncertainty limits are 2σ and include estimated systematic errors. Local and global annually averaged lifetimes for the (E)- and (Z)-R-316c isomers were calculated using a 2-D atmospheric model to be 74.6 ± 3 and 114.1 ± 10 years, respectively, where the estimated uncertainties are due solely to the uncertainty in the UV absorption spectra. Stratospheric photolysis is the predominant atmospheric loss process for both isomers with the O((1)D) reaction making a minor, ~2% for the (E) isomer and 7% for the (Z) isomer, contribution to the total atmospheric loss. Ozone depletion potentials for (E)- and (Z)-R-316c were calculated using the 2-D model to be 0.46 and 0.54, respectively. Infrared absorption spectra for (E)- and (Z)-R-316c were measured at 296 K and used to estimate their radiative efficiencies (REs) and GWPs; 100-year time-horizon GWPs of 4160 and 5400 were obtained for (E)- and (Z)-R-316c, respectively. Both isomers of R-316c are shown in this work to be long-lived ozone depleting substances and potent greenhouse gases.

20.
J Pers Med ; 11(11)2021 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-34834578

RESUMEN

A formal assessment of pharmacogenomics clinical decision support (PGx-CDS) by providers is lacking in the literature. The objective of this study was to evaluate the usability of PGx-CDS tools that have been implemented in a healthcare setting. We enrolled ten prescribing healthcare providers and had them complete a 60-min usability session, which included interacting with two PGx-CDS scenarios using the "Think Aloud" technique, as well as completing the Computer System Usability Questionnaire (CSUQ). Providers reported positive comments, negative comments, and suggestions for the two PGx-CDS during the usability testing. Most provider comments were in favor of the current PGx-CDS design, with the exception of how the genotype and phenotype information is displayed. The mean CSUQ score for the PGx-CDS overall satisfaction was 6.3 ± 0.95, with seven strongly agreeing and one strongly disagreeing for overall satisfaction. The implemented PGx-CDS at our institution was well received by prescribing healthcare providers. The feedback collected from the session will guide future PGx-CDS designs for our healthcare system and provide a framework for other institutions implementing PGx-CDS.

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