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1.
Nature ; 616(7957): 448-451, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36858072

RESUMEN

The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, the secondary of near-Earth binary asteroid (65803) Didymos, and changing the orbital period of Dimorphos. A change in orbital period of approximately 7 min was expected if the incident momentum from the DART spacecraft was directly transferred to the asteroid target in a perfectly inelastic collision1, but studies of the probable impact conditions and asteroid properties indicated that a considerable momentum enhancement (ß) was possible2,3. In the years before impact, we used lightcurve observations to accurately determine the pre-impact orbit parameters of Dimorphos with respect to Didymos4-6. Here we report the change in the orbital period of Dimorphos as a result of the DART kinetic impact to be -33.0 ± 1.0 (3σ) min. Using new Earth-based lightcurve and radar observations, two independent approaches determined identical values for the change in the orbital period. This large orbit period change suggests that ejecta contributed a substantial amount of momentum to the asteroid beyond what the DART spacecraft carried.

2.
Nature ; 616(7957): 443-447, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36858073

RESUMEN

Although no known asteroid poses a threat to Earth for at least the next century, the catalogue of near-Earth asteroids is incomplete for objects whose impacts would produce regional devastation1,2. Several approaches have been proposed to potentially prevent an asteroid impact with Earth by deflecting or disrupting an asteroid1-3. A test of kinetic impact technology was identified as the highest-priority space mission related to asteroid mitigation1. NASA's Double Asteroid Redirection Test (DART) mission is a full-scale test of kinetic impact technology. The mission's target asteroid was Dimorphos, the secondary member of the S-type binary near-Earth asteroid (65803) Didymos. This binary asteroid system was chosen to enable ground-based telescopes to quantify the asteroid deflection caused by the impact of the DART spacecraft4. Although past missions have utilized impactors to investigate the properties of small bodies5,6, those earlier missions were not intended to deflect their targets and did not achieve measurable deflections. Here we report the DART spacecraft's autonomous kinetic impact into Dimorphos and reconstruct the impact event, including the timeline leading to impact, the location and nature of the DART impact site, and the size and shape of Dimorphos. The successful impact of the DART spacecraft with Dimorphos and the resulting change in the orbit of Dimorphos7 demonstrates that kinetic impactor technology is a viable technique to potentially defend Earth if necessary.

3.
Nature ; 616(7957): 457-460, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36858075

RESUMEN

The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of the binary asteroid (65803) Didymos, at 23:14 UTC on 26 September 2022 as a planetary defence test1. DART was the first hypervelocity impact experiment on an asteroid at size and velocity scales relevant to planetary defence, intended to validate kinetic impact as a means of asteroid deflection. Here we report a determination of the momentum transferred to an asteroid by kinetic impact. On the basis of the change in the binary orbit period2, we find an instantaneous reduction in Dimorphos's along-track orbital velocity component of 2.70 ± 0.10 mm s-1, indicating enhanced momentum transfer due to recoil from ejecta streams produced by the impact3,4. For a Dimorphos bulk density range of 1,500 to 3,300 kg m-3, we find that the expected value of the momentum enhancement factor, ß, ranges between 2.2 and 4.9, depending on the mass of Dimorphos. If Dimorphos and Didymos are assumed to have equal densities of 2,400 kg m-3, [Formula: see text]. These ß values indicate that substantially more momentum was transferred to Dimorphos from the escaping impact ejecta than was incident with DART. Therefore, the DART kinetic impact was highly effective in deflecting the asteroid Dimorphos.

4.
J Hand Surg Am ; 48(4): 354-360, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36725391

RESUMEN

PURPOSE: Brachial plexus injuries (BPIs) are devastating to patients not only functionally but also financially. Like patients experiencing other traumatic injuries and unexpected medical events, patients with BPIs are at risk of catastrophic health expenditure (CHE) in which out-of-pocket health spending exceeds 40% of postsubsistence income (income remaining after food and housing expenses). The individual financial strain after BPIs has not been previously quantified. The purpose of this study was to assess the proportion of patients with BPIs who experience risk of CHE after reconstructive surgery. METHODS: Administrative databases were used from 8 states to identify patients who underwent surgery for BPIs. Demographics including age, sex, race, and insurance payer type were obtained. Inpatient billing records were used to determine the total surgical and inpatient facility costs within 90 days after the initial surgery. Due to data constraints, further analysis was only conducted for privately-insured patients. The proportion of patients with BPIs at risk of CHE was recorded. Predictors of CHE risk were determined from a multivariable regression analysis. RESULTS: Among 681 privately-insured patients undergoing surgery for BPIs, nearly one-third (216 [32%]) were at risk of CHE. Black race and patients aged between 25 and 39 years were significant risk factors associated with CHE. Sex and the number of comorbidities were not associated with risk of CHE. CONCLUSIONS: Nearly one-third of privately-insured patients met the threshold for being at risk of CHE after BPI surgery. CLINICAL RELEVANCE: Identifying those patients at risk of CHE can inform strategies to minimize long-term financial distress after BPIs, including detailed counseling regarding anticipated health care expenditures and efforts to optimize access to appropriate insurance policies for patients with BPIs.


Asunto(s)
Plexo Braquial , Gastos en Salud , Humanos , Adulto , Plexo Braquial/lesiones , Renta , Factores de Riesgo , Bases de Datos Factuales
5.
Neurobiol Dis ; 158: 105486, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34450329

RESUMEN

Non-convulsive epileptiform activity is a common and under-studied comorbidity of Alzheimer's disease that may significantly contribute to onset of clinical symptoms independently of other neuropathological features such as ß-amyloid deposition. We used repeated treatment with low dose kainic acid (KA) to trigger sub-threshold epileptiform activity in young (less than 6 months) wild-type (WT) and APP/PSEN1 mice to test the role of disruption to the glutamatergic system in epileptiform activity changes and the development of memory deficits. Short-term repeated low-dose KA (five daily treatments with 5 mg/kg, IP) impaired long-term potentiation in hippocampus of APP/PSEN1 but not WT mice. Long-term repeated low-dose KA (fourteen weeks of bi-weekly treatment with 7.5-10 mg/kg) led to high mortality in APP/PSEN1 mice. KA treatment also impaired memory retention in the APP/PSEN1 mice in a Morris water maze task under cognitively challenging reversal learning conditions where the platform was moved to a new location. Four weeks of bi-weekly treatment with 5 mg/kg KA also increased abnormal spike activity in APP/PSEN1 and not WT mice but did not impact sleep/wake behavioral states. These findings suggest that hyperexcitability in Alzheimer's disease may indeed be an early contributor to cognitive decline that is independent of heavy ß-amyloid-plaque load, which is absent in APP/PSEN1 mice under 6 months of age.


Asunto(s)
Precursor de Proteína beta-Amiloide/genética , Disfunción Cognitiva/genética , Disfunción Cognitiva/metabolismo , Ácido Glutámico/metabolismo , Homeostasis/fisiología , Presenilina-1/genética , Animales , Electroencefalografía , Epilepsia/inducido químicamente , Epilepsia/genética , Femenino , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Ácido Kaínico , Potenciación a Largo Plazo , Aprendizaje por Laberinto/efectos de los fármacos , Trastornos de la Memoria/inducido químicamente , Trastornos de la Memoria/psicología , Ratones , Ratones Endogámicos C57BL , Placa Amiloide/patología
6.
Nature ; 514(7521): 202-4, 2014 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-25297433

RESUMEN

The majority of ultraluminous X-ray sources are point sources that are spatially offset from the nuclei of nearby galaxies and whose X-ray luminosities exceed the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes. Their X-ray luminosities in the 0.5-10 kiloelectronvolt energy band range from 10(39) to 10(41) ergs per second. Because higher masses imply less extreme ratios of the luminosity to the isotropic Eddington limit, theoretical models have focused on black hole rather than neutron star systems. The most challenging sources to explain are those at the luminous end of the range (more than 10(40) ergs per second), which require black hole masses of 50-100 times the solar value or significant departures from the standard thin disk accretion that powers bright Galactic X-ray binaries, or both. Here we report broadband X-ray observations of the nuclear region of the galaxy M82 that reveal pulsations with an average period of 1.37 seconds and a 2.5-day sinusoidal modulation. The pulsations result from the rotation of a magnetized neutron star, and the modulation arises from its binary orbit. The pulsed flux alone corresponds to an X-ray luminosity in the 3-30 kiloelectronvolt range of 4.9 × 10(39) ergs per second. The pulsating source is spatially coincident with a variable source that can reach an X-ray luminosity in the 0.3-10 kiloelectronvolt range of 1.8 × 10(40) ergs per second. This association implies a luminosity of about 100 times the Eddington limit for a 1.4-solar-mass object, or more than ten times brighter than any known accreting pulsar. This implies that neutron stars may not be rare in the ultraluminous X-ray population, and it challenges physical models for the accretion of matter onto magnetized compact objects.

7.
Nature ; 506(7488): 339-42, 2014 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-24553239

RESUMEN

Asymmetry is required by most numerical simulations of stellar core-collapse explosions, but the form it takes differs significantly among models. The spatial distribution of radioactive (44)Ti, synthesized in an exploding star near the boundary between material falling back onto the collapsing core and that ejected into the surrounding medium, directly probes the explosion asymmetries. Cassiopeia A is a young, nearby, core-collapse remnant from which (44)Ti emission has previously been detected but not imaged. Asymmetries in the explosion have been indirectly inferred from a high ratio of observed (44)Ti emission to estimated (56)Ni emission, from optical light echoes, and from jet-like features seen in the X-ray and optical ejecta. Here we report spatial maps and spectral properties of the (44)Ti in Cassiopeia A. This may explain the unexpected lack of correlation between the (44)Ti and iron X-ray emission, the latter being visible only in shock-heated material. The observed spatial distribution rules out symmetric explosions even with a high level of convective mixing, as well as highly asymmetric bipolar explosions resulting from a fast-rotating progenitor. Instead, these observations provide strong evidence for the development of low-mode convective instabilities in core-collapse supernovae.

8.
J Hand Surg Am ; 45(5): 427-432, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32089379

RESUMEN

PURPOSE: The primary objective of this study was to compare incidence, demographic trends, and rates of subsequent fusion between proximal row carpectomy (PRC) and 4-corner fusion (4CF) among patients in the United States. METHODS: A total of 3,636 patients who underwent PRC and 5,047 who underwent 4CF were identified from the years 2005 through 2014 among enrollees in the PearlDiver database. Regional distribution, demographic characteristics, annual incidence, comorbidities, and subsequent wrist fusion were compared between the 2 groups. Of the patients identified, 3,512 from each group were age- and sex-matched and subsequently compared for rates of converted fusion, 30- and 90-day readmission rates, and average direct cost. RESULTS: Patients undergoing 4CF and PRC did not have statistically significant differences in comorbidities. The incidence of the procedures among all subscribers increased for both PRC (1.8 per 10,000 to 2.6 per 10,000) and 4CF (1.2 per 10,000 to 2.0 per 10,000) from 2005 to 2014. Comparing the matched cohorts, patients who underwent 4CF had a higher rate of subsequent fusion than those who underwent PRC (2.67% vs 1.79%). Readmission rates were not significantly different at 30 or 90 days. Average direct cost was significantly greater for 4CF than for PRC. CONCLUSIONS: Both PRC and 4CF have been utilized at increasing rates in the past decade. Wrist fusion rates and average costs are higher in the 4CF group without a significant difference in readmission rates. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.


Asunto(s)
Huesos del Carpo , Artrodesis , Humanos , Incidencia , Rango del Movimiento Articular , Resultado del Tratamiento , Articulación de la Muñeca
9.
J Strength Cond Res ; 34(1): 235-248, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30113919

RESUMEN

Nunes, RFH, Cidral-Filho, FJ, Flores, LJF, Nakamura, FY, Rodriguez, HFM, Bobinski, F, De Sousa, A, Petronilho, F, Danielski, LG, Martins, MM, Martins, DF, and Guglielmo, LGA. Effects of far-infrared emitting ceramic materials on recovery during 2-week preseason of elite futsal players. J Strength Cond Res 34(1): 235-248, 2020-We investigated the effects of far-infrared emitting ceramic materials (cFIR) during overnight sleep on neuromuscular, biochemical and perceptual markers in futsal players. Twenty athletes performed a 2-week preseason training program and during sleep wore bioceramic (BIO; n = 10) or placebo pants (PL; n = 10). Performance (countermovement jump [CMJ]; squat jump [SJ]; sprints 5, 10, and 15-m) and biochemical markers (tumor necrosis factor alpha-TNF-α, interleukin 10-IL-10, thiobarbituric acid-reactive species [TBARS], carbonyl, superoxide dismutase [SOD], catalase [CAT]) were obtained at baseline and after the 1st and 2nd week of training. Delayed-onset muscle soreness (DOMS) and training strain were monitored throughout. Changes in ΔCMJ and ΔSJ were possibly (60/36/4 [week-1]) and likely (76/22/2 [week-2]) higher in BIO. Both groups were faster in 5-m sprint in week 2 compared with baseline (p = 0.015), furthermore, BIO was likely faster in 10-m sprint (3/25/72 [week 1]). Significant group × time interaction in %ΔTNF-α were observed (p = 0.024 [week-1]; p = 0.021 [week-2]) with values possibly (53/44/3 [week 1]) and likely (80/19/1 [week 2]) higher in BIO. The %ΔIL-10 decreased across weeks compared with baseline (p = 0.019 [week-1]; p = 0.026 [week-2]), showing values likely higher in BIO (81/16/3 [week-1]; 80/17/3 [week-2]). Significant weekly increases in %ΔTBARS (p = 0.001 [week-1]; p = 0.011 [week-2]) and %ΔCarbonyl (p = 0.002 [week-1]; p < 0.001 [week-2]) were observed compared with baseline, showing likely (91/5/4 [week-1]) and possibly (68/30/2 [week-2]) higher changes in BIO. Significant weekly decreases in %ΔSOD were observed compared with baseline (p = 0.046 [week 1]; p = 0.011 [week-2]), and between week 2 and week 1 (p = 0.021), in addition to significant decreases in %ΔCAT compared with baseline (p = 0.070 [week 1]; p = 0.012 [week 2]). Training strain (p = 0.021; very -likely [0/2/98]; week 1) and DOMS was lower in BIO (likely; 7 sessions) with differences over time (p = 0.001). The results suggest that the daily use of cFIR clothing could facilitate recovery, especially on perceptual markers during the early phases of an intensive training period.


Asunto(s)
Rendimiento Atlético/fisiología , Rayos Infrarrojos/uso terapéutico , Acondicionamiento Físico Humano/fisiología , Fútbol/fisiología , Adulto , Biomarcadores/sangre , Catalasa/sangre , Cerámica , Vestuario , Método Doble Ciego , Prueba de Esfuerzo , Humanos , Interleucina-10/sangre , Movimiento , Fuerza Muscular/fisiología , Músculo Esquelético/fisiopatología , Mialgia/etiología , Mialgia/terapia , Acondicionamiento Físico Humano/efectos adversos , Recuperación de la Función , Carrera , Sueño , Superóxido Dismutasa/sangre , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Factor de Necrosis Tumoral alfa/sangre , Adulto Joven
10.
Nature ; 494(7438): 449-51, 2013 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-23446416

RESUMEN

Broad X-ray emission lines from neutral and partially ionized iron observed in active galaxies have been interpreted as fluorescence produced by the reflection of hard X-rays off the inner edge of an accretion disk. In this model, line broadening and distortion result from rapid rotation and relativistic effects near the black hole, the line shape being sensitive to its spin. Alternative models in which the distortions result from absorption by intervening structures provide an equally good description of the data, and there has been no general agreement on which is correct. Recent claims that the black hole (2 × 10(6) solar masses) at the centre of the galaxy NGC 1365 is rotating at close to its maximum possible speed rest on the assumption of relativistic reflection. Here we report X-ray observations of NGC 1365 that reveal the relativistic disk features through broadened Fe-line emission and an associated Compton scattering excess of 10-30 kiloelectronvolts. Using temporal and spectral analyses, we disentangle continuum changes due to time-variable absorption from reflection, which we find arises from a region within 2.5 gravitational radii of the rapidly spinning black hole. Absorption-dominated models that do not include relativistic disk reflection can be ruled out both statistically and on physical grounds.

11.
Am J Transplant ; 17(3): 712-723, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27597148

RESUMEN

An unbalanced microbiome may lead to disease by creating aberrant immune responses. A recent association of cellular rejection with the development of interstitial fibrosis and tubular atrophy (IFTA) suggests the role of immune-mediated tissue injury. We hypothesized that developing IFTA correlates with altered urinary tract microbiomes (UMBs). UMBs at two serial time points, 1 and 6-8 months posttransplant, were assessed by 16S microbial ribosomal gene sequencing in 25 patients developing biopsy-proven IFTA compared to 23 transplant patients with normal biopsies and excellent function (TX) and 20 healthy nontransplant controls (HC). Streptococcus, the dominant genera in HC males, was lower in IFTA and TX males at 1 month compared to HCs. At 6-8 months, Streptococcus was further decreased in IFTA males, but normalized in TX. IFTA males and females had increases in number of genera per sample at 6-8 months. UMB composition varied substantially between individuals in all groups. Despite the wide variation in UMBs between individuals, IFTA was associated with a loss in dominant resident urinary microbes in males, and a parallel increase in nonresident, pathogenic bacteria in males and females. UMB changes may contribute to IFTA development by alteration of the host immune response.


Asunto(s)
Atrofia/orina , Biomarcadores/orina , Fibrosis/orina , Rechazo de Injerto/orina , Trasplante de Riñón/efectos adversos , Túbulos Renales/patología , Enfermedades Pulmonares Intersticiales/orina , Microbiota/genética , Atrofia/etiología , Biopsia , Estudios de Casos y Controles , Femenino , Fibrosis/etiología , Estudios de Seguimiento , Tasa de Filtración Glomerular , Rechazo de Injerto/etiología , Rechazo de Injerto/patología , Supervivencia de Injerto , Humanos , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/cirugía , Pruebas de Función Renal , Túbulos Renales/metabolismo , Enfermedades Pulmonares Intersticiales/etiología , Masculino , Persona de Mediana Edad , Pronóstico , ARN Ribosómico 16S/genética , Factores de Riesgo
12.
Am J Transplant ; 17(8): 2103-2116, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28188669

RESUMEN

We performed orthogonal technology comparisons of concurrent peripheral blood and biopsy tissue samples from 69 kidney transplant recipients who underwent comprehensive algorithm-driven clinical phenotyping. The sample cohort included patients with normal protocol biopsies and stable transplant (sTx) function (n = 25), subclinical acute rejection (subAR, n = 23), and clinical acute rejection (cAR, n = 21). Comparisons between microarray and RNA sequencing (RNA-seq) signatures were performed and demonstrated a strong correlation between the blood and tissue compartments for both technology platforms. A number of shared differentially expressed genes and pathways between subAR and cAR in both platforms strongly suggest that these two clinical phenotypes form a continuum of alloimmune activation. SubAR is associated with fewer or less expressed genes than cAR in blood, whereas in biopsy tissues, this clinical phenotype demonstrates a more robust molecular signature for both platforms. The discovery work done in this study confirms a clear ability to detect gene expression profiles for sTx, subAR, and cAR in both blood and biopsy tissue, yielding equivalent predictive performance that is agnostic to both technology and platform. Our data also provide strong biological insights into the molecular mechanisms underlying these signatures, underscoring their logistical potential as molecular diagnostics to improve clinical outcomes following kidney transplantation.


Asunto(s)
Biomarcadores/metabolismo , Perfilación de la Expresión Génica , Rechazo de Injerto/diagnóstico , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Fallo Renal Crónico/genética , Trasplante de Riñón/efectos adversos , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Rechazo de Injerto/sangre , Rechazo de Injerto/epidemiología , Rechazo de Injerto/genética , Supervivencia de Injerto , Humanos , Fallo Renal Crónico/cirugía , Masculino , Persona de Mediana Edad , Prevalencia , Pronóstico , Estudios Prospectivos , Adulto Joven
13.
Eur Spine J ; 26(4): 1236-1245, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-27885477

RESUMEN

PURPOSE: With growing older population and increasing rates of cervical spinal surgery, it is vital to understand the value of cervical surgery in this population. We set forth to determine the cost utility following anterior cervical decompression and fusion (ACDF) for degenerative disease in older patients. METHODS: Patients undergoing ACDF for degenerative diseases were enrolled into prospective longitudinal registry. Patient-reported outcomes (PROs) were recorded at baseline, 1-year, and 2-year postoperatively. Two-year medical resource utilization, missed work, and health-state values [quality-adjusted life years (QALYs)] were assessed to compute cost per QALY gained. Patients were dichotomized based on age: <65 years (younger) and ≥65 years (older) to compare the cost utility in these age groups. RESULTS: Total 218 (87%) younger patients and 33 (13%) older patients who underwent ACDF were analyzed. Both the groups demonstrated a significant improvement in PROs 2-year following surgery. The older patients had a lower mean cumulative gain in QALYs compared to younger patients at 1 year (0.141 vs. 0.28, P = 0.05) and 2 years (0.211 vs. 0.424, P = 0.04). There was no significant difference in the mean total 2-year cost between older [$21,041 (95% CI $18,466-$23,616)] and younger [$22,669 (95% CI $$21,259-$24,079)] patients (P = 0.27). Two-year cost per QALY gained in older vs. younger patients was ($99,720/QALYs gained vs. ($53,464/QALYs gained, P = 0.68). CONCLUSION: ACDF surgery provided a significant gain in health-state utility in older patients with degenerative cervical pathology, with a mean cumulative 2-year cost per QALY gained of $99,720/QALY. While older patients have a slightly higher cost utility compared to their younger counterparts, surgery in the older cohort does provide a significant improvement in pain, disability, and quality-of-life outcomes.


Asunto(s)
Discectomía , Desplazamiento del Disco Intervertebral/cirugía , Medición de Resultados Informados por el Paciente , Fusión Vertebral , Estenosis Espinal/cirugía , Espondilosis/cirugía , Factores de Edad , Anciano , Análisis Costo-Beneficio , Evaluación de la Discapacidad , Discectomía/economía , Femenino , Humanos , Desplazamiento del Disco Intervertebral/economía , Estudios Longitudinales , Masculino , Estudios Prospectivos , Años de Vida Ajustados por Calidad de Vida , Sistema de Registros , Fusión Vertebral/economía , Estenosis Espinal/economía , Espondilosis/economía , Estados Unidos
14.
Eur Spine J ; 25(3): 843-9, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26310840

RESUMEN

PURPOSE: Evaluate the factors associated with postoperative ICU admission in patients undergoing surgical management of degenerative lumbar spine disease. METHODS: Patients undergoing surgery for degenerative lumbar spine disease were enrolled into a prospective registry over a 2-year period. Preoperative variables (age, gender, ASA grade, ODI%, CAD, HTN, MI, CHF, DM, BMI, depression, anxiety) and surgical variables (instrumentation, arthrodesis, estimated blood loss, length of surgery) were collected prospectively. Postoperative ICU admission details were retrospectively determined from the electronic medical record. Student's t test (continuous variables) and Chi-square test (categorical variables) were used to determine the association of each preoperative and surgical variable with ICU admission. RESULTS: 808 Patients (273 laminectomy, 535 laminectomy and fusion) were evaluated. Forty-one (5.1%) patients were found to have postoperative ICU admissions. Reasons for admission included blood loss (12.2%), cardiac (29.3%), respiratory (19.5%), neurologic (31.7%), and other (7.3%). For preoperative variables, female gender (P < 0.001), history of CAD (P = 0.003), history of MI (P = 0.008), history of CHF (P = 0.001), age (P = 0.025), and ASA grade (P = 0.008) were significantly associated with ICU admission. For surgical variables, estimated blood loss (P < 0.001) and length of surgery (P < 0.001) were significantly associated with ICU admission. CONCLUSIONS: Age, female gender, ASA grade, cardiac comorbidities, intraoperative blood loss, and length of surgery were associated with increased risk of postoperative ICU admission. Knowledge of these factors can aid surgeons in patient selection and preoperative discussion with patients about potential need for unexpected admission to the ICU.


Asunto(s)
Unidades de Cuidados Intensivos , Vértebras Lumbares/cirugía , Admisión del Paciente/estadística & datos numéricos , Cuidados Posoperatorios , Enfermedades de la Columna Vertebral/cirugía , Adulto , Factores de Edad , Anciano , Pérdida de Sangre Quirúrgica , Enfermedades Cardiovasculares/epidemiología , Comorbilidad , Femenino , Humanos , Laminectomía , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Tempo Operativo , Estudios Prospectivos , Sistema de Registros , Factores Sexuales , Fusión Vertebral , Estados Unidos/epidemiología
15.
J Surg Orthop Adv ; 25(1): 49-53, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27082888

RESUMEN

The purpose of this study was to investigate operative costs and postoperative complication rates in relation to utilization of locking versus nonlocking implants in isolated, lower limb fractures. Seventy-seven patients underwent plate fixation of isolated bicondylar tibial plateau, bimalleolar ankle, and trimalleolar ankle fractures at a large tertiary care center. Fixation with locking versus nonlocking implants was compared to incidence of postsurgical complications. Costs of these implants were directly compared. No significant correlation was found between locking versus nonlocking implants and incidence of complications. However, the cost of fixation with locking implants was significantly greater than nonlocking for all fractures. Utilization of more costly locking implants was not associated with reduced postoperative complications compared with nonlocking implants. More attention must be dedicated toward maximizing cost efficiency, since uniform usage of nonlocking implants has the potential to reduce surgical costs without compromising patient outcomes in isolated lower extremity fractures.


Asunto(s)
Fracturas de Tobillo/cirugía , Placas Óseas/economía , Fijación Interna de Fracturas/instrumentación , Costos de la Atención en Salud , Traumatismos de la Rodilla/cirugía , Complicaciones Posoperatorias , Fracturas de la Tibia/cirugía , Adolescente , Adulto , Anciano , Estudios de Cohortes , Femenino , Fijación Interna de Fracturas/economía , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
16.
Opt Express ; 23(11): A582-93, 2015 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-26072883

RESUMEN

This study evaluates the capability of atmospheric CO2 column measurements under cloudy conditions using an airborne intensity-modulated continuous-wave integrated-path-differential-absorption lidar operating in the 1.57-µm CO2 absorption band. The atmospheric CO2 column amounts from the aircraft to the tops of optically thick cumulus clouds and to the surface in the presence of optically thin clouds are retrieved from lidar data obtained during the summer 2011 and spring 2013 flight campaigns, respectively. For the case of intervening thin cirrus clouds with an average cloud optical depth of about 0.16 over an arid/semi-arid area, the CO2 column measurements from 12.2 km altitude were found to be consistent with the cloud free conditions with a lower precision due to the additional optical attenuation of the thin clouds. The clear sky precision for this flight campaign case was about 0.72% for a 0.1-s integration, which was close to previously reported flight campaign results. For a vegetated area and lidar path lengths of 8 to 12 km, the precision of the measured differential absorption optical depths to the surface was 1.3 - 2.2% for 0.1-s integration. The precision of the CO2 column measurements to thick clouds with reflectance about 1/10 of that of the surface was about a factor of 2 to 3 lower than that to the surface owing to weaker lidar returns from clouds and a smaller CO2 differential absorption optical depth compared to that for the entire column.

17.
J Hand Surg Am ; 40(3): 505-7, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25618844

RESUMEN

PURPOSE: To determine the incidence and reasons for hardware removal after operative fixation of distal radius fractures. METHODS: We retrospectively reviewed 33 patients who underwent removal of a volar distal radius plate from 2007 to 2013. We recorded the primary reason for plate removal, patient sex, body mass index, AO fracture type, and plate manufacturer. The total number of both distal radius plating procedures and implant removals was analyzed. RESULTS: Of the 33 patients who underwent implant removal, the most common reasons for removal were pain (30%), tenosynovitis (27%), malunion (24%), infection (12%), nonunion (6%), and tendon rupture (3%). The most common AO fracture types requiring plate removal were A2, C2, and C3 (7 each). A total of 517 distal radius fractures received plate fixation at our institution from 2007 to 2009, a number that rose to 610 from 2010 to 2012. The number of distal radius plate removals over that same time was relatively constant at 17 and 16, respectively. CONCLUSIONS: We advise continued review of reasons for implant removal to limit future hardware complications related to volar plating of distal radius fractures. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.


Asunto(s)
Placas Óseas/efectos adversos , Remoción de Dispositivos/estadística & datos numéricos , Fijación Interna de Fracturas/instrumentación , Fracturas del Radio/cirugía , Traumatismos de la Muñeca/cirugía , Adulto , Anciano , Estudios de Cohortes , Intervalos de Confianza , Remoción de Dispositivos/métodos , Femenino , Fijación Interna de Fracturas/efectos adversos , Fijación Interna de Fracturas/métodos , Humanos , Incidencia , Puntaje de Gravedad del Traumatismo , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/fisiopatología , Complicaciones Posoperatorias/cirugía , Pronóstico , Radiografía , Fracturas del Radio/diagnóstico por imagen , Estudios Retrospectivos , Medición de Riesgo , Resultado del Tratamiento , Traumatismos de la Muñeca/diagnóstico por imagen
18.
Gene Ther ; 21(6): 618-28, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24784447

RESUMEN

Effective gene therapy strategies for the treatment of kidney disorders remain elusive. We report an optimized kidney-targeted gene delivery strategy using recombinant adeno-associated virus (rAAV) administered via retrograde renal vein injection in mice. Renal vein injection of rAAV consistently resulted in superior kidney transduction compared with tail vein injection using as little as half the tail vein dose. We compared rAAV5, 6, 8 and 9, containing either green fluorescent protein (GFP) or luciferase reporter genes driven by the Cytomegalovirus promoter. We demonstrated that although rAAV6 and 8 injected via renal vein transduced the kidney, transgene expression was mainly restricted to the medulla. Transgene expression was systematically low after rAAV5 injection, attributed to T-cell immune response, which could be overcome by transient immunosuppression. However, rAAV9 was the only serotype that permitted high-transduction efficiency of both the cortex and medulla. Moreover, both the glomeruli and tubules were targeted, with a higher efficiency within the glomeruli. To improve the specificity of kidney-targeted gene delivery with rAAV9, we used the parathyroid hormone receptor 'kidney-specific' promoter. We obtained a more efficient transgene expression within the kidney, and a significant reduction in other tissues. Our work represents the first comprehensive and clinically relevant study for kidney gene delivery.


Asunto(s)
Dependovirus/genética , Vectores Genéticos/administración & dosificación , Venas Renales/efectos de los fármacos , Animales , Terapia Genética/métodos , Inyecciones , Riñón/efectos de los fármacos , Riñón/fisiología , Ratones Endogámicos C57BL , Regiones Promotoras Genéticas , Receptor de Hormona Paratiroídea Tipo 1/genética , Cola (estructura animal) , Transducción Genética , Transgenes
19.
Opt Express ; 22 Suppl 6: A1634-40, 2014 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-25607320

RESUMEN

A new modulation technique for Continuous Wave (CW) Lidar is presented based on Binary Phase Shift Keying (BPSK) using orthogonal carriers closely spaced in frequency, modulated by Maximum Length (ML) sequences, which have a theoretical autocorrelation function with no sidelobes. This makes it possible to conduct multi-channel atmospheric differential absorption measurements in the presence of thin clouds without the need for further processing to remove errors caused by sidelobe interference while sharing the same modulation bandwidth. Flight tests were performed and data were collected using both BPSK and linear swept frequency modulation. This research shows there is minimal or no sidelobe interference in the presence of thin clouds for BPSK compared to linear swept frequency with significant sidelobe levels. Comparisons between of CO(2) optical depth Signal to Noise (SNR) between the BPSK and linear swept frequency cases indicate a 21% drop in SNR for BPSK experimentally using the instrument under consideration.


Asunto(s)
Artefactos , Atmósfera/química , Dióxido de Carbono/análisis , Fotometría/instrumentación , Tecnología de Sensores Remotos/instrumentación , Procesamiento de Señales Asistido por Computador/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , Almacenamiento y Recuperación de la Información/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
20.
Opt Lett ; 39(20): 6078-81, 2014 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-25361160

RESUMEN

An interpolation method is described for range measurements of high precision and altimetry using repeating intensity-modulated continuous wave (IM-CW) lidar waveforms, where the range is determined by means of a cross-correlation between the digital form of the transmitted signal and the digitized return signal collected by the lidar receiver. This method uses reordering of the array elements in the frequency domain to convert a repeating synthetic pulse signal to single highly interpolated pulse. The computation of this processing is marginally greater than the correlation itself, as it only involves reordering of the correlation in the frequency domain, which makes it possible to implement this in a real time application. It is shown through theoretical arguments and flight-testing that this is a viable method for high-speed interpolated range measurements. Standard deviation is 0.75 m over water with only 350 mw of transmitted power at 2600 m.

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