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1.
Proc Natl Acad Sci U S A ; 119(31): e2200354119, 2022 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-35878021

RESUMEN

Nitrous oxide (N2O) is an important greenhouse gas (GHG) that also contributes to depletion of ozone in the stratosphere. Agricultural soils account for about 60% of anthropogenic N2O emissions. Most national GHG reporting to the United Nations Framework Convention on Climate Change assumes nitrogen (N) additions drive emissions during the growing season, but soil freezing and thawing during spring is also an important driver in cold climates. We show that both atmospheric inversions and newly implemented bottom-up modeling approaches exhibit large N2O pulses in the northcentral region of the United States during early spring and this increases annual N2O emissions from croplands and grasslands reported in the national GHG inventory by 6 to 16%. Considering this, emission accounting in cold climate regions is very likely underestimated in most national reporting frameworks. Current commitments related to the Paris Agreement and COP26 emphasize reductions of carbon compounds. Assuming these targets are met, the importance of accurately accounting and mitigating N2O increases once CO2 and CH4 are phased out. Hence, the N2O emission underestimate introduces additional risks into meeting long-term climate goals.

3.
Artif Organs ; 41(1): 55-65, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28093803

RESUMEN

The objective of this study is to evaluate electrocardiography (ECG)-synchronized pulsatile flow under varying heart rates and different atrial and ventricular arrhythmias in a simulated extracorporeal life support (ECLS) system. The ECLS circuit consisted of an i-cor diagonal pump and console, an iLA membrane ventilator, and an 18 Fr arterial cannula. The circuit was primed with lactated Ringer's solution and packed red blood cells (hematocrit 35%). An ECG simulator was used to trigger pulsatile flow and to generate selected cardiac rhythms. All trials were conducted at a flow rate of 2.5 L/min at room temperature for normal sinus rhythm at 45-180 bpm under non-pulsatile and pulsatile modes. Various atrial and ventricular arrhythmias were also tested. Real-time pressure and flow data were recorded using a custom-based data acquisition system. The energy equivalent pressure (EEP) generated by pulsatile flow was always higher than the mean pressure. No surplus hemodynamic energy (SHE) was recorded under non-pulsatile mode. Under pulsatile mode, SHE levels increased with increasing heart rates (45-120 bpm). SHE levels under a 1:2 assist ratio were higher than the 1:1 and 1:3 assist ratios with a heart rate of 180 bpm. A similar trend was recorded for total hemodynamic energy levels. There was no statistical difference between the two perfusion modes with regards to pressure drops across the ECLS circuit. The main resistance and energy loss came from the arterial cannula. The i-cor console successfully tracked electrocardiographic signals of 12 atrial and ventricular arrhythmias. Our results demonstrated that the i-cor pulsatile ECLS system can be synchronized with a normal heart rate or with various atrial/ventricular arrhythmias. Further in vivo studies are warranted to confirm our findings.


Asunto(s)
Arritmias Cardíacas/fisiopatología , Oxigenación por Membrana Extracorpórea/instrumentación , Frecuencia Cardíaca , Flujo Pulsátil , Electrocardiografía/instrumentación , Diseño de Equipo , Hemodinámica , Humanos , Sistemas de Manutención de la Vida/instrumentación
4.
Artif Organs ; 41(1): 17-24, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27735070

RESUMEN

The objective of this study was to evaluate an alternative neonatal extracorporeal life support (ECLS) circuit with a RotaFlow centrifugal pump and Better-Bladder (BB) for hemodynamic performance and gaseous microemboli (GME) capture in a simulated neonatal ECLS system. The circuit consisted of a Maquet RotaFlow centrifugal pump, a Quadrox-iD Pediatric diffusion membrane oxygenator, 8 Fr arterial cannula, and 10 Fr venous cannula. A "Y" connector was inserted into the venous line to allow for comparison between BB and no BB. The circuit and pseudopatient were primed with lactated Ringer's solution and packed human red blood cells (hematocrit 35%). All hemodynamic trials were conducted at flow rates ranging from 100 to 600 mL/min at 36°C. Real-time pressure and flow data were recorded using a data acquisition system. For GME testing, 0.5 cc of air was injected via syringe into the venous line. GME were detected and characterized with or without the BB using the Emboli Detection and Classification Quantifier (EDAC) System. Trials were conducted at flow rates ranging from 200 to 500 mL/min. The hemodynamic energy data showed that up to 75.2% of the total hemodynamic energy was lost from the circuit. The greatest pressure drops occurred across the arterial cannula and increased with increasing flow rate from 10.1 mm Hg at 100 mL/min to 114.3 mm Hg at 600 mL/min. The EDAC results showed that the BB trapped a significant amount of the GME in the circuit. When the bladder was removed, GME passed through the pump head and the oxygenator to the arterial line. This study showed that a RotaFlow centrifugal pump combined with a BB can help to significantly decrease the number of GME in a neonatal ECLS circuit. Even with this optimized alternative circuit, a large percentage of the total hemodynamic energy was lost. The arterial cannula was the main source of resistance in the circuit.


Asunto(s)
Oxigenación por Membrana Extracorpórea/instrumentación , Velocidad del Flujo Sanguíneo , Dispositivos de Protección Embólica , Diseño de Equipo , Hemodinámica , Humanos , Recién Nacido , Modelos Cardiovasculares , Presión
5.
Artif Organs ; 41(1): 70-75, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27862035

RESUMEN

The objective of this study is to evaluate the impact of an open or closed recirculation line on flow rate, circuit pressure, and hemodynamic energy transmission in simulated neonatal extracorporeal life support (ECLS) systems. The two neonatal ECLS circuits consisted of a Maquet HL20 roller pump (RP group) or a RotaFlow centrifugal pump (CP group), Quadrox-iD Pediatric oxygenator, and Biomedicus arterial and venous cannulae (8 Fr and 10 Fr) primed with lactated Ringer's solution and packed red blood cells (hematocrit 35%). Trials were conducted at flow rates ranging from 200 to 600 mL/min (200 mL/min increments) with a closed or open recirculation line at 36°C. Real-time pressure and flow data were recorded using a custom-based data acquisition system. In the RP group, the preoxygenator flow did not change when the recirculation line was open while the prearterial cannula flow decreased by 15.7-20.0% (P < 0.01). Circuit pressure, total circuit pressure drop, and hemodynamic energy delivered to patients also decreased (P < 0.01). In the CP group, the prearterial cannula flow did not change while preoxygenator flow increased by 13.6-18.8% (P < 0.01). Circuit pressure drop and hemodynamic energy transmission remained the same. The results showed that the shunt of an open recirculation line could decrease perfusion flow in patients in the ECLS circuit using a roller pump, but did not change perfusion flow in the circuit using a centrifugal pump. An additional flow sensor is needed to monitor perfusion flow in patients if any shunts exist in the ECLS circuit.


Asunto(s)
Oxigenación por Membrana Extracorpórea/instrumentación , Velocidad del Flujo Sanguíneo , Centrifugación/instrumentación , Simulación por Computador , Diseño de Equipo , Eritrocitos/citología , Hemodinámica , Humanos , Recién Nacido , Sistemas de Manutención de la Vida/instrumentación , Modelos Cardiovasculares , Presión
6.
Sci Rep ; 13(1): 14564, 2023 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-37666947

RESUMEN

Natural climate solutions provide opportunities to reduce greenhouse gas emissions and the United States is among a growing number of countries promoting storage of carbon in agricultural soils as part of the climate solution. Historical patterns of soil organic carbon (SOC) stock changes provide context about mitigation potential. Therefore, our objective was to quantify the influence of climate-smart soil practices on SOC stock changes in the top 30 cm of mineral soils for croplands in the United States using the DayCent Ecosystem Model. We estimated that SOC stocks increased annually in US croplands from 1995 to 2015, with the largest increase in 1996 of 16.6 Mt C (95% confidence interval ranging from 6.1 to 28.2 Mt CO2 eq.) and the lowest increase in 2015 of 10.6 Mt C (95% confidence interval ranging from - 1.8 to 22.2 Mt C). Most climate-smart soil practices contributed to increases in SOC stocks except for winter cover crops, which had a negligible impact due to a relatively small area with cover crop adoption. Our study suggests that there is potential for enhancing C sinks in cropland soils of the United States although some of the potential has been realized due to past adoption of climate-smart soil practices.

7.
Biochem Biophys Res Commun ; 426(1): 12-7, 2012 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-22902537

RESUMEN

Telomeres protect the ends of linear chromosomes, which if eroded to a critical length can become uncapped and lead to replicative senescence. Telomerase maintains telomere length in some cells, but inappropriate expression facilitates the immortality of cancer cells. Recently, proteins involved in RNA processing and ribosome assembly, such as hnRNP (heterogeneous nuclear ribonucleoprotein) A1, have been found to participate in telomere maintenance in mammals. The Saccharomyces cerevisiae protein Npl3 shares significant amino acid sequence similarities with hnRNP A1. We found that deleting NPL3 accelerated the senescence of telomerase null cells. The highly conserved RNA recognition motifs (RRM) in Npl3 appear to be important for preventing faster senescence. Npl3 preferentially binds telomere sequences in vitro, suggesting that Npl3 may affect telomeres directly. Despite similarities between the two proteins, human hnRNP A1 is unable to complement the lack of Npl3 to rescue accelerated senescence in tlc1 npl3 cells. Deletion of CBC2, which encodes another hnRNP-related protein that associates with Npl3, also accelerates senescence. Potential mechanisms by which hnRNP-related proteins maintain telomeres are discussed.


Asunto(s)
Ribonucleoproteínas Nucleares Heterogéneas/metabolismo , Complejo Proteico Nuclear de Unión a la Caperuza/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Unión al ARN/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiología , Homeostasis del Telómero , Telómero/fisiología , Senescencia Celular/genética , ADN/metabolismo , ADN de Cadena Simple/metabolismo , Ribonucleoproteína Nuclear Heterogénea A1 , Ribonucleoproteína Heterogénea-Nuclear Grupo A-B , Ribonucleoproteínas Nucleares Heterogéneas/genética , Humanos , Complejo Proteico Nuclear de Unión a la Caperuza/genética , Proteínas Nucleares/genética , Proteínas de Unión al ARN/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética
8.
Surg Pract Sci ; 10: 100116, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36540700

RESUMEN

Introduction: During the first surge of the COVID-19 pandemic, healthcare utilization changed. We sought to examine the impact of the first COVID-19 surge on the outcomes of patients whose elective surgeries for diverticulitis were postponed and those who underwent urgent surgery during the surge. Materials and methods: This was a retrospective study from a single tertiary center in the Northeast of the US. Patients whose elective surgeries were delayed, or who underwent urgent surgery for diverticulitis during the first COVID-19 surge (3/16/2020 to 8/1/2020) were included. A cohort from 2019 was used for comparison. Variables were compared between groups including: procedure, death, length of stay, disposition, stoma rate, technique for surgery, and leak rate. Results: Forty-five patients were included in the COVID-19 group and 44 patients in the 2019 group. Twenty-seven patients had elective surgeries delayed during the COVID-19 surge. Ten (37%) required more urgent surgery, 80% with complicated disease. Six (22%) were admitted to the hospital and 13 (48%) required additional antibiotics. Eight (30%) patients postponed their surgeries indefinitely and 7 (26%) had surgery once permitted. There were no observed differences between the two groups in the rate of complicated disease, leaks, technique for surgery or stoma rate. Conclusions: During the first COVID-19 surge, over 1/3 of patients whose elective diverticulitis surgeries were postponed required urgent surgery, a majority of whom had complicated disease. There were no apparent differences in outcomes when compared to a pre-pandemic cohort, highlighting the importance of a triage system with the ability to escalate surgery in a timely manner.

10.
Am J Manag Care ; 13(9): 506-12, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17803364

RESUMEN

OBJECTIVE: To evaluate the impact of a pentavalent combination vaccine on childhood immunization coverage rates and timeliness within a managed care organization. STUDY DESIGN: Retrospective matched-cohort analysis of encounter data from administrative claims and a state immunization registry. METHODS: Children were stratified into 2 demographically matched cohorts (combination and reference), based on receipt of the DTaP/HepB/IPV combination vaccine. Children were followed until 24 months of age, and coverage rates and on-time rates were assessed. Outcomes were measured for the HEDIS Combination 2 vaccine series (4 doses of diphtheria/tetanus/pertussis, 3 doses of polio, 1 dose of measles/mumps/rubella, 3 doses of Haemophilus influenzae type b, 3 doses of hepatitis B, and 1 dose of varicella) and each vaccine series individually. RESULTS: Children in the combination cohort were significantly more likely to be fully vaccinated for the HEDIS Combination 2 series by 2 years of age and to be vaccinated within the recommended age ranges. In the combination cohort 86.9% (752/865) of patients were fully covered compared with only 74.1% (641/865) of the reference cohort (P <.001). In the combination cohort 45.2% (391/865) of patients received vaccinations on time versus 37.5% (324/865) of the reference cohort, P = .001. CONCLUSIONS: Receipt of DTaP/HepB/IPV was associated with improved coverage and age-appropriate immunization in a managed care population.


Asunto(s)
Vacuna contra la Varicela/administración & dosificación , Servicios de Salud del Niño/estadística & datos numéricos , Vacunas contra Haemophilus/administración & dosificación , Vacunas contra Hepatitis B/administración & dosificación , Programas de Inmunización/normas , Esquemas de Inmunización , Programas Controlados de Atención en Salud/normas , Vacuna contra el Sarampión-Parotiditis-Rubéola/administración & dosificación , Vacunación/estadística & datos numéricos , Vacunas Combinadas/administración & dosificación , Servicios de Salud del Niño/organización & administración , Protección a la Infancia/estadística & datos numéricos , Preescolar , Estudios de Cohortes , Femenino , Humanos , Programas de Inmunización/estadística & datos numéricos , Lactante , Recién Nacido , Masculino , Programas Controlados de Atención en Salud/organización & administración , Indicadores de Calidad de la Atención de Salud , Estudios Retrospectivos , Estados Unidos/epidemiología , Vacunas Conjugadas/administración & dosificación
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