Complicaciones de la laringectomía total: experiencia de 7 años en un hospital universitario de Paraguay / Complications of total laryngectomy: a 7-year experience in a university hospital in Paraguay

Introducción: El cáncer de laringe es la neoplasia maligna más común de las vías aerodigestivas superiores. La laringectomía total es el tratamiento de elección en casos avanzados, pero se asocia a una alta tasa de complicaciones. Objetivos: Conocer la prevalencia de las complicaciones posquirúrgicas de la laringectomía total y los factores asociados en pacientes con cáncer de laringe. Materiales y métodos: Estudio observacional, descriptivo, retrospectivo, de corte transversal, revisando el comportamiento de la laringectomía total y sus principales complicaciones en la Cátedra y Servicio de Otorrinolaringología del Hospital de Clínicas de la Facultad de Ciencias Médicas de la Universidad Nacional de Asunción, Paraguay, de 2015 a 2022. Se incluyeron pacientes mayores de 18 años, de ambos sexos, postoperados de laringectomía total, con diagnóstico anatomopatológico de neoplasia de laringe. Se excluyeron pacientes no operados, con fichas incompletas o que abandonaron el tratamiento. Se analizaron variables demográficas, clínicas, quirúrgicas y anatomopatológicas. Resultados: Se incluyeron 10 pacientes, todos varones, con edad media de 56,3 ± 10,2 años. El 90% presentaba hábitos tóxicos. La complicación más frecuente fue la fístula faringocutánea (70%), seguida por infección del sitio quirúrgico (10%) y sangrado posoperatorio (10%). El 71,4% de las fístulas se resolvieron con medidas conservadoras. El 30% tenía afectación supraglótica y el 57,1% de los que presentaron complicaciones recibieron radioterapia previa. Conclusión: Las complicaciones de la laringectomía total son frecuentes, principalmente la fístula faringocutánea. La afectación supraglótica y la radioterapia previa se asociaron a mayor tasa de complicaciones. Se requieren estudios prospectivos con muestras más grandes para confirmar estos hallazgos.

Introduction: Laryngeal cancer is the most common malignant neoplasm of the upper aerodigestive tract. Total laryngectomy is the treatment of choice in advanced cases, but it is associated with a high rate of complications. Objectives: To determine the prevalence of postoperative complications of total laryngectomy and associated factors in patients with laryngeal cancer. Materials and methods: Observational, descriptive, retrospective, cross-sectional study, reviewing the behavior of total laryngectomy and its main complications in the Department of Otorhinolaryngology of the Hospital de Clínicas, Faculty of Medical Sciences, National University of Asunción, Paraguay, from 2015 to 2022. Patients over 18 years of age, of both sexes, who underwent total laryngectomy, with anatomopathological diagnosis of laryngeal neoplasm were included. Non-operated patients, those with incomplete records or who abandoned treatment were excluded. Demographic, clinical, surgical and anatomopathological variables were analyzed. Results: Ten patients were included, all male, with a mean age of 56.3 ± 10.2 years. Ninety percent had toxic habits. The most frequent complication was pharyngocutaneous fistula (70%), followed by surgical site infection (10%) and postoperative bleeding (10%). Conservative measures resolved 71.4% of the fistulas. Thirty percent had supraglottic involvement and 57.1% of those who presented complications received previous radiotherapy. Conclusion: Complications of total laryngectomy are frequent, mainly pharyngocutaneous fistula. Supraglottic involvement and previous radiotherapy were associated with a higher rate of complications. Prospective studies with larger samples are required to confirm these findings.

Implementation of a bundle to improve HIV testing during hospitalization for people who inject drugs.

Background: Increased HIV testing is essential to ending the HIV epidemic. People who inject drugs (PWID) are among the highest risk for HIV infection. Previous research at Tufts Medical Center identified low HIV testing rates in hospitalized PWID. Our research team aimed to identify and overcome barriers to inpatient HIV screening of PWID using implementation science methods. Methods: Stakeholders were engaged to gather perspectives on barriers and facilitators of HIV testing. A PWID care bundle was developed and implemented, which included (1) HIV screening; (2) hepatitis A, B, and C testing and vaccination; (3) medications for opioid use disorder; and (4) naloxone prescription. Strategies from all nine Expert Recommendations for Implementing Change (ERIC) clusters guided the implementation plan. Stakeholder feedback was gathered throughout implementation, and implementation outcomes of acceptability and feasibility were assessed. Results: PWID overall felt comfortable with HIV testing being offered while hospitalized. Clinicians cited that the main barriers to HIV testing were discomfort and confusion around consenting requirements. Many resident physicians surveyed reported that, at times, they forgot HIV testing for PWID. Overall, though, resident physicians felt that the PWID bundle was useful and did not distract from other patient care responsibilities. Conclusions: Engagement of key stakeholders to increase HIV testing in an inpatient setting led to the implementation of a PWID bundle, which was feasible and acceptable. Bundling evidence-informed care elements for inpatient PWID should be investigated further.

People who inject drugs (PWID) are at an increased risk of contracting HIV. HIV testing is a key strategy to stop the spread of HIV. Our study created a bundle of services and tests to offer to all PWID who were admitted to the hospital. The bundle included HIV testing; hepatitis A, B, and C testing and vaccination; medications for opioid use disorder; and prescription for Narcan, a medication that can reverse opioid overdose. We then asked doctors and patients how they felt about the bundle and any barriers and facilitators that they predicted for expanding HIV testing to PWID while admitted to the hospital. Patients were accepting of expanding HIV testing, and resident physicians felt it was important as well and was a manageable addition to their list of responsibilities. However, the most likely part of the bundle to be forgotten was HIV testing. This study lays the groundwork for bundling services for PWID while they are hospitalized. We also highlight areas for future exploration.

Quantification of glycated hemoglobin and glucose in vivo using Raman spectroscopy and artificial neural networks.

Undiagnosed type 2 diabetes (T2D) remains a major public health concern. The global estimation of undiagnosed diabetes is about 46%, being this situation more critical in developing countries. Therefore, we proposed a non-invasive method to quantify glycated hemoglobin (HbA1c) and glucose in vivo. We developed a technique based on Raman spectroscopy, RReliefF as a feature selection method, and regression based on feed-forward artificial neural networks (FFNN). The spectra were obtained from the forearm, wrist, and index finger of 46 individuals. The use of FFNN allowed us to achieve an error in the predictive model of 0.69% for HbA1c and 30.12 mg/dL for glucose. Patients were classified according to HbA1c values into three categories: healthy, prediabetes, and T2D. The proposed method obtained a specificity and sensitivity of 87.50% and 80.77%, respectively. This work demonstrates the benefit of using artificial neural networks and feature selection techniques to enhance Raman spectra processing to determine glycated hemoglobin and glucose in patients with undiagnosed T2D.

Trends in risk behaviors and sexually transmitted infections among youth presenting to a sexually transmitted infection clinic in the United States, 2013-2017.

Background: Sexually transmitted infections (STIs) are increasing among adolescents and young adults (AYA) across the United States. However, data are scarce on trends in condom use, number of partners, and other STI risk factors among AYA. The present study evaluated associations between sexual behaviors and STI diagnoses over time among AYA. Methods: We evaluated linked encounters of AYA aged 13-26 attending an urban Northeast public STI clinic from 2013-2017. Demographics, risk behaviors, self-reported past year and lifetime STI, and STI diagnosis during clinic encounter (positive test for urine, oral, or anal chlamydia; urine, oral, or anal gonorrhea; urine trichomonas; HIV; and syphilis) were extracted from electronic health records. We estimated prevalence and performed trend analyses of the repeated cross-sectional data. Cochran-Armitage and Kruskal-Wallis trend test were conducted for categorical and continuous variables, respectively. Results: Among 3822 encounters, clinical STIs demonstrated statistically significant increases including chlamydia (+9%, p = 0.001), gonorrhea (+5%, p = 0.008), and syphilis (+3%, p = 0.006) all of which significantly increased over time, as did any STI (+10%, p < 0.001). HIV and trichomonas rates remained low and unchanged. Self-reported STI increased as well, both past year (+9%) and lifetime (+14%). Greater proportions of AYA reported multiple partners (+9%, p < 0.001), and condomless oral (+12%, p = 0.001) and vaginal/anal (+7%, p = 0.001) sex. Conclusion: Among AYA presenting to a STI clinic, the proportion who engaged in condomless sex and had multiple partners increased over a 5 year period, which corresponded to increased STI prevalence during this period. Preventions efforts for AYA should continue to emphasize the importance of condoms and partner selection.

Pharmacogenomic polygenic risk score for clopidogrel responsiveness among Caribbean Hispanics: A candidate gene approach.

This multicenter clinical study was aimed at conducting a targeted pharmacogenomic association analysis of residual on-clopidogrel platelet reactivity in 474 Caribbean Hispanic patients. Platelet reactivity was measured using the VerifyNow P2Y12 assay and clopidogrel resistance was defined as P2Y12 reaction units (PRUs) greater than or equal to 208. Genotyping was performed using the whole-genome Infinium MEGA BeadChip array. An ancestry-adjusted, weighted polygenic risk score (wPGxRS) was developed to account for the effect of multiple variants on PRU and compared between clopidogrel responders and nonresponders. The mean PRU across the study cohort was 173.8 ± 68.5 and 33.5% of patients were defined as clopidogrel resistant. Multivariate linear regression showed that 19% of PRU variability was attributed to nine independent predictors, with CYP2C19*2 (rs4244285) accounting for ~ 7% of observed PRU variation (p < 0.001). PON1 rs662, ABCB1/MDR1 rs2032582, PEAR1 rs12041331 carrier status, and the interaction between African ancestry and rs12041331 carriers also predicted PRU among the participants (p ≤ 0.05). A clear gene-dose effect was detected between PRU and CYP2C19*2 genotype, consistent with previous studies in European patient populations, as well as rs12777823. Importantly, a significant positive correlation was detected between our novel wPGxRS (4 variants) and PRU among the Hispanic patient population (rp  = 0.35, p < 0.001). Moreover, the wPGxRS discriminated between nonresponders and responders (p = 0.003), indicating that this multigene-based score is a useful predictor of clopidogrel resistance among Caribbean Hispanics. Taken together, these results help close the gap of knowledge on clopidogrel pharmacogenomics and its potential clinical implementation in this under-represented population.

Almacenamiento de carbono en sistemas agroforestales en los Llanos Orientales de Colombia / Carbon storage in agroforestry systems in Colombia's Eastern Plains

Introducción: Los cultivos de café, cacao y pasturas para la ganadería son actividades agropecuarias de interés económico en Colombia. Cuando estas actividades se desarrollan bajo sistemas agroforestales (SAF) promueven la conservación e incrementan la fijación de carbono y, por ende, la mitigación del cambio climático. Objetivo: El estudio estimó el almacenamiento de carbono en la biomasa aérea, necromasa y carbono orgánico del suelo bajo SAF con cacao (SAF cacao), SAF con café (café SAF), sistemas silvopastoriles (SSP) y bosque en el municipio de Mesetas, Meta (Colombia). Métodos: Se establecieron 44 parcelas de muestreo, en donde se tomaron medidas dasométricas a individuos con un diámetro del tronco a la altura del pecho (dap) ≥ 2.5 cm (latizales, fustales y fustales grandes), cuyos valores fueron transformados a carbono con modelos de biomasa y una fracción de carbono default. En los tres sistemas agropecuarios, se contó el número de árboles de cacao, café, plantas asociadas y se identificó el tipo de uso (maderable, alimento, combustión). Resultados: El almacenamiento de carbono presentó diferencias significativas (P < 0.0001) entre usos del suelo. La mayor acumulación se encontró en bosque, con 216.6 t C ha-1, superando en 59, 72 y 73 % a SAF cacao, SSP y SAF café, respectivamente. Fabaceae, Lauraceae y Primulaceae presentaron el mayor almacenamiento de carbono. En SAF cacao, la mayor acumulación de carbono fue encontrada en especies para alimento humano; en SAF café y SSP, el mayor almacenamiento fue presentado en las especies maderables. Conclusión: Estos resultados resaltan el potencial de almacenamiento de carbono en los sistemas productivos de mayor importancia en el departamento del Meta, lo cual es importante para el diseño de estrategias que permitan integrar acciones de mitigación de emisiones de gases de efecto invernadero y promover la economía campesina local.

Introduction: Coffee, cocoa crops and pastures for livestock are agricultural activities of economic interest in Colombia. When these activities are developed under agroforestry systems (AFS), they promote conservation and increase carbon fixation and, therefore, climate change mitigation. Objective: The study estimated carbon storage in aboveground biomass, necromass and soil organic carbon under SAF with cocoa (SAF cocoa), SAF with coffee (SAF coffee), silvopastoral systems (SPS) and forest in Mesetas, Meta (Colombia). Methods: Forty-four sampling plots were established, where dasometric measurements were taken from individuals with a trunk diameter at breast height (dbh) ≥ 2.5 cm (saplings, trees and large trees), whose values were transformed to carbon with biomass models and a default carbon fraction. In the three agricultural systems, the number of cocoa and coffee trees and associated plants was counted, and the type of use (timber, food, combustion) was identified. Results: Carbon storage showed significant differences (P < 0.0001) among land uses. The highest accumulation was found in forest, with 216.6 t C ha-1, exceeding in 59, 72 and 73 % to SAF cocoa, SSP and SAF coffee, respectively. The botanical families Fabaceae, Lauraceae and Primulaceae presented the greatest carbon storage. In SAF cocoa, the greatest accumulation of carbon was found in species for human food; in SAF coffee and SSP, the greatest storage was presented by timber species. Conclusion: These results highlight the potential for carbon storage in the most important productive systems in the Meta department, which is important for designing strategies that allow for integrating actions to mitigate greenhouse gas emissions and to promote the local peasant economy.

Implementing a pharmacogenetic-driven algorithm to guide dual antiplatelet therapy (DAPT) in Caribbean Hispanics: protocol for a non-randomised clinical trial.

INTRODUCTION: Minority populations in the USA are disproportionately affected by cardiovascular conditions. Reduced responsiveness to clopidogrel among carriers of CYP2C19 variants has been reported in patients with either coronary artery disease (CAD) or acute coronary syndrome (ACS) after the percutaneous coronary intervention (PCI). Previous studies have evaluated CYP2C19 genotyping-guided antiplatelet therapy in selected populations; however, this has yet to be tested among Hispanics. Given the paucity of clinical research on CYP2C19 and antiplatelet clinical outcomes in Hispanics, our study will test the safety and efficacy of a genetic-driven treatment algorithm to guide dual antiplatelet therapy (DAPT) in Caribbean Hispanics. METHODS AND ANALYSIS: This is a multicentre, prospective, non-randomised clinical trial that proposes an assessment of pharmacogenomic-guided DAPT in post-PCI Caribbean Hispanic patients with ACS or CAD. We will recruit 250 patients to be compared with a matched non-concurrent cohort of 250 clopidogrel-treated patients (standard-of-care). Major adverse cardiovascular events (MACEs) such as all-cause death, myocardial infarction (MI), stroke, coronary revascularisation, stent thrombosis and bleedings over 6 months will be the study endpoints. Among the recruited, high-risk patients will be escalated to ticagrelor and low-risk patients will remain on clopidogrel. The primary objective is to determine whether genetic-guided therapy is superior to standard of care. The secondary objective will determine if clopidogrel treatment in low-risk patients is not associated with a higher rate of MACEs compared with escalated antiplatelet therapy in high-risk patients. Patients will be enrolled up to the group's completion. ETHICS AND DISSEMINATION: Approval was obtained from the Institutional Review Board of the University of Puerto Rico Medical Sciences Campus (protocol # A4070417). The study will be carried out in compliance with the Declaration of Helsinki and International Conference on Harmonization Good Clinical Practice Guidelines. Findings will be published in a peer-reviewed journal and controlled access to experimental data will be available. TRIAL REGISTRATION NUMBER: NCT03419325; Pre-results.

Do Patients with Pre-Existing Psychiatric Illness Have an Increased Risk of Infection after Injury?

BACKGROUND: Trauma remains a leading cause of death and long term-morbidity. We have shown that patients who sustain traumatic injuries are at increased risk for the development of infectious complications. Psychiatric illnesses (PIs) are also noted to occur frequently among the general population. The presence of a PI has been shown to be a risk factor for the development of infections. Despite the prevalence of both traumatic injuries and psychiatric diseases, there are little data relating the impact of PI on the outcome of patients with trauma. We hypothesize that the presence of a PI will be associated with an increased risk of an infection developing after injury. PATIENTS AND METHODS: This is a five year retrospective chart review of all admitted patients with trauma age 18 years and older. Patients with and without a major psychiatric illness were compared. Demographic data, mechanism of injury and Injury Severity Score (ISS) were reviewed. Co-morbidities included diabetes mellitus, obesity, pre-injury steroid use, and International Classification of Diseases, 9th edition, based psychiatric illness. All infections were diagnosed by microbiologic criteria (urinary tract infection [UTI], ventilator-associated pneumonia) or Centers for Disease Control and Prevention criteria for clinically evident infections (surgical site infection). RESULTS: Of the 11,147 admitted trauma patients, 14.5% had a pre-injury PI diagnosis. The PI patients were older (61.5 ± 0.5 vs. 54.3; p < 0.001), more often female (56% vs. 39.1%; p < 0.001), and had no difference in blunt mechanism rates (88.4% vs. 89.9%; p = 0.06) or median ISS (9 vs. 9; p = 0.06). There was no difference between PI and non-PI patients in pre-injury diabetes mellitus (13.4% vs. 12.7%; p = 0.4), steroid use (2.5% vs. 1.9%; p = 0.1), but patients with PI were more likely to be obese (15.7% vs. 13.6%; p = 0.03). Patients with PI were more likely to have an infection develop (10.4% vs. 7.5%; p < 0.001). The most common infection in both groups was UTI (6.9% vs. 4.2%; p < 0.001). Compared with non-PI patients, adjusting for age, gender, ISS, diabetes mellitus, and obesity, patients with PI were more likely to have an infection develop (odds ratio 1.3, 95% confidence interval = 1.1-1.5) Conclusions: Patients with an underlying PI are at increased risk of having a UTI after traumatic injury. This study identifies a previously unknown independent risk factor for UTIs in patients with trauma. This stresses the need for increased awareness and attention to this vulnerable population.

Effect of the influence function of deformable mirrors on laser beam shaping.

The continuous membrane stiffness of a deformable mirror propagates the deformation of the actuators beyond their neighbors. When phase-retrieval algorithms are used to determine the desired shape of these mirrors, this cross-coupling-also known as influence function (IF)-is generally disregarded. We study this problem via simulations and bench tests for different target shapes to gain further insight into the phenomenon. Sound modeling of the IF effect is achieved as highlighted by the concurrence between the modeled and experimental results. In addition, we observe that the actuators IF is a key parameter that determines the accuracy of the output light pattern. Finally, it is shown that in some cases it is possible to achieve better shaping by modifying the input irradiance of the phase-retrieval algorithm. The results obtained from this analysis open the door to further improvements in this type of beam-shaping systems.

Trauma patients who present in a delayed fashion: a unique and challenging population.

BACKGROUND: A proportion of trauma patients present for evaluation in a delayed fashion after injury, likely due to a variety of medical and nonmedical reasons. There has been little investigation into the characteristics and outcomes of trauma patients who present delayed. We hypothesize that trauma patients who present in a delayed fashion are a unique population at risk of increased trauma-related complications. MATERIALS AND METHODS: This was a retrospective review from 2010-2015 at a Level I trauma center. Patients were termed delayed if they presented >24 hours after injury. Patients admitted within 24 hours of their injury were the comparison group. Charts were reviewed for demographics, mechanism, comorbidities, complications and outcomes. A subgroup analysis was done on patients who suffered falls. RESULTS: During the 5-y period, 11,705 patients were admitted. A total of 588 patients (5%) presented >24 h after their injury. Patients in the delayed group were older (65 versus 55 y, P < 0.001) and more likely to have psychiatric comorbidities (33% vs. 24%, P = 0.0001) than the control group. They were also more likely to suffer substance withdrawal (8.9% vs. 4.1%, P < 0.001) but had toxicology testing for drugs and alcohol done at significantly lower rates. Patients that presented delayed after falls were similar in age and injury severity score (ISS) but more likely to suffer substance withdrawal when compared to those with falls that presented within 24 hours. Patients with falls that presented delayed had toxicology testing at significantly lower rates than the comparison group. CONCLUSIONS: Trauma patients that present to the hospital in a delayed fashion have unique characteristics and are more likely to suffer negative outcomes including substance withdrawal. Future goals will include exploring strategies for early intervention, such as automatic withdrawal monitoring and social work referral for all patients who present in a delayed fashion.

Transforming the canonical piecewise-linear model into a smooth-piecewise representation.

A smoothed representation (based on natural exponential and logarithmic functions) for the canonical piecewise-linear model, is presented. The result is a completely differentiable formulation that exhibits interesting properties, like preserving the parameters of the original piecewise-linear model in such a way that they can be directly inherited to the smooth model in order to determine their parameters, the capability of controlling not only the smoothness grade, but also the approximation accuracy at specific breakpoint locations, a lower or equal overshooting for high order derivatives in comparison with other approaches, and the additional advantage of being expressed in a reduced mathematical form with only two types of inverse functions (logarithmic and exponential). By numerical simulation examples, this proposal is verified and well-illustrated.

Impact of Type of Health Insurance on Infection Rates among Young Trauma Patients.

BACKGROUND: Many studies have described the detrimental effect of lack of health insurance on trauma-related outcomes. It is unclear, though, whether these effects are related to pre-injury health status, access to trauma centers, or differences in quality of care after presentation. The aim of this study was to determine if patient and insurance type affect outcomes after trauma surgery. METHODS: We conducted a retrospective chart review of prospectively collected data at the American College of Surgeons level 1 trauma registry in Rhode Island. All blunt trauma patients aged 18-45 observed from 2004 to 2014 were included. Patients were divided into one of four groups on the basis of their type of insurance: Private/commercial, Medicare, Medicaid, and uninsured. Co-morbidities and infections were recorded. Analysis of variance or the Mann-Whitney U test, as appropriate, was used to analyze the data. RESULTS: A total of 8,018 patients were included. Uninsured patients were more likely to be male and younger, whereas the Medicare patient group had significantly fewer male patients. Rates of co-morbidities were highest in the Medicare group (28.1%) versus the private insurance (16.7%), Medicaid (19.9%), and uninsured (12.9%) groups (p < 0.05). However, among patients with any co-morbidity, there was no difference in the average number of co-morbidities between insurance groups. The rate of infection was highest in Medicaid patients (7.7%) versus private (5.6%), Medicare (6.3%), and uninsured (4.3%) patients (p < 0.05). Only Medicaid was associated with a significantly greater risk of developing a post-injury infection (odds ratio 1.6; 95% confidence interval 1.1-2.3). CONCLUSION: The presence of insurance, namely Medicaid, does not equate to diagnosis and management of conditions that affect trauma outcomes. Medicaid is associated with worse pre-trauma health maintenance and a greater risk of infection.

Preoperative Myocardial Injury as a Predictor of Mortality in Emergency General Surgery: An Analysis Using the American College of Surgeons NSQIP Database.

BACKGROUND: Recent studies have linked postoperative serum troponin elevation to mortality in a range of different clinical scenarios. To date, there has been no investigation into the significance of preoperative troponin elevation in emergency general surgery (EGS) patients. We define this as preoperative myocardial injury (PMI). We hypothesize that PMI seen in EGS patients may predict postoperative morbidity and mortality. STUDY DESIGN: Using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database, we performed a retrospective review of all EGS cases between 2008 and 2014. Patients with preoperative troponin I drawn were compared. RESULTS: There were 464 EGS patients who had troponin I measurements preoperatively. Eighty-two (18%) had preoperative troponin elevations. Patients with PMI were more likely to have the following preoperative physiologic derangements: acute renal failure (18% vs 4%; p = 0.002) and septic shock (40% vs 13%; p < 0.001). Patient comorbidities associated with PMI included congestive heart failure (13% vs 3%; p = 0.007), dialysis dependence (16% vs 3%; p = 0.002), and American Society of Anesthesiologists (ASA) class ≥ 4 (52% vs 29%; p < 0.001). Compared with controls, patients with PMI had higher rates of postoperative events (77% vs 52%; p < 0.001) and mortality (34% vs 13%; p = 0.009). Univariate analysis showed that patients with PMI had an increased risk of postoperative events (odds ratio [OR] 3.02; 95% CI 1.74 to 5.25) and mortality (OR 3.53; 95% CI 1.66 to 7.47). Multivariate analysis revealed preoperative troponin I elevation was an independent predictor of mortality (OR 3.03; 95% CI 1.19 to 7.72, p = 0.020). CONCLUSIONS: Emergency general surgery patients with PMI are at increased risk for postoperative events and death. Preoperative myocardial injury is an independent predictor of mortality and has prognostic utility that can prepare surgical teams for adverse events so that they can be recognized, evaluated, and treated earlier.

Bioenergy Development Policy and Practice Must Recognize Potential Hydrologic Impacts: Lessons from the Americas.

Large-scale bioenergy production will affect the hydrologic cycle in multiple ways, including changes in canopy interception, evapotranspiration, infiltration, and the quantity and quality of surface runoff and groundwater recharge. As such, the water footprints of bioenergy sources vary significantly by type of feedstock, soil characteristics, cultivation practices, and hydro-climatic regime. Furthermore, water management implications of bioenergy production depend on existing land use, relative water availability, and competing water uses at a watershed scale. This paper reviews previous research on the water resource impacts of bioenergy production-from plot-scale hydrologic and nutrient cycling impacts to watershed and regional scale hydro-economic systems relationships. Primary gaps in knowledge that hinder policy development for integrated management of water-bioenergy systems are highlighted. Four case studies in the Americas are analyzed to illustrate relevant spatial and temporal scales for impact assessment, along with unique aspects of biofuel production compared to other agroforestry systems, such as energy-related conflicts and tradeoffs. Based on the case studies, the potential benefits of integrated resource management are assessed, as is the need for further case-specific research.

Beam shaping for laser-based adaptive optics in astronomy.

The availability and performance of laser-based adaptive optics (AO) systems are strongly dependent on the power and quality of the laser beam before being projected to the sky. Frequent and time-consuming alignment procedures are usually required in the laser systems with free-space optics to optimize the beam. Despite these procedures, significant distortions of the laser beam have been observed during the first two years of operation of the Gemini South multi-conjugate adaptive optics system (GeMS). A beam shaping concept with two deformable mirrors is investigated in order to provide automated optimization of the laser quality for astronomical AO. This study aims at demonstrating the correction of quasi-static aberrations of the laser, in both amplitude and phase, testing a prototype of this two-deformable mirror concept on GeMS. The paper presents the results of the preparatory study before the experimental phase. An algorithm to control amplitude and phase correction, based on phase retrieval techniques, is presented with a novel unwrapping method. Its performance is assessed via numerical simulations, using aberrations measured at GeMS as reference. The results predict effective amplitude and phase correction of the laser distortions with about 120 actuators per mirror and a separation of 1.4 m between the mirrors. The spot size is estimated to be reduced by up to 15% thanks to the correction. In terms of AO noise level, this has the same benefit as increasing the photon flux by 40%.

Pupil aberrations in Offner spectrometers.

The light path function (LPF) of an Offner spectrometer is presented. The evaluation of the LPF of this spectrometer enables its imaging properties to be studied for arbitrary object and image positions, while avoiding the more complicated analysis of intermediate images generated by the diffraction grating, which is often involved. A power series expansion of the LPF on the grating coordinates directly determines pupil aberrations of the generated spectrum and facilitates the search for configurations with small low-order aberrations. This analysis not only confirms the possibility of reducing low-order aberrations in Rowland-type mounts, namely astigmatism and coma, as predicted in previous studies, but also proves that all third-order terms in the series expansion of the aberration function can be canceled at the image of the design point and for the corresponding design wavelength, when the design point is located on a plane orthogonal to the optical axis. Furthermore, fourth-order terms are computed and shown to represent the most relevant contribution to image blurring. Third- and fourth-order aberrations are also evaluated for Rowland mounts with the design point located outside the aforementioned plane. The study described in this manuscript is not restricted to small angles of incidence, and, therefore, it goes beyond Seidel and Buchdahl aberrations.

Administration of high doses of copper to capuchin monkeys does not cause liver damage but induces transcriptional activation of hepatic proliferative responses.

Liver cells respond to copper loading upregulating protective mechanisms. However, to date, except for liver content, there are no good indicators that identify individuals with excess liver copper. We hypothesized that administering high doses of copper to young (5.5 mg Cu · kg⁻¹ . d⁻¹) and adult (7.5 mg Cu · kg⁻¹ . d⁻¹) capuchin monkeys would induce detectable liver damage. Study groups included adult monkeys (2 females, 2 males) 3-3.5 y old at enrollment treated with copper for 36 mo (ACu); age-matched controls (1 female, 3 males) that did not receive additional copper (AC); young monkeys (2 female, 2 males) treated from birth with copper for 36 mo (YCu); and young age-matched controls (2 female, 2 males) that did not receive additional copper (YC). We periodically assessed clinical, blood biochemical, and liver histological indicators and at 36 mo the hepatic mRNA abundance of MT2a, APP, DMT1, CTR1, HGF, TGFß, and NFκΒ only in adult monkeys. After 36 mo, the liver copper concentration was 4-5 times greater in treated monkeys relative to controls. All monkeys remained healthy with normal routine serum biochemical indices and there was no evidence of liver tissue damage. Relative mRNA abundance of HGF, TGFß and NFκB was significantly greater in ACu than in AC monkeys. In conclusion, capuchin monkeys exposed to copper at doses up to 50 times the current upper level enhanced expression of genes related to inflammation and injury without clinical, blood biochemical, or histological evidence of liver damage.

Design of Dyson imaging spectrometers based on the Rowland circle concept.

We aim to show that Dyson imaging spectrometers can be easily designed by applying the concept of the Rowland circle to refracting surfaces. This allows us to conceive an analytical procedure that is based on the removal of astigmatism at two wavelengths. Following this procedure, high-optical-quality spectrometers can be designed even for high speeds. Root-mean-square spot radii less than 2.5 µm are obtained for speeds as high as f/1.5, slit lengths of 15 mm, and wavelength ranges of 0.4-1.7 µm. Design examples are presented for classical Dyson spectrometers in which the detector is glued to the glass plane surface and for spectrometers with an air gap between this surface and the image plane.

Off-plane anastigmatic imaging in Offner spectrometers.

In this paper, the imaging performance of an Offner concentric imaging spectrometer is analyzed when the spectrometer entrance slit is disposed arbitrarily on the plane that is parallel to the grating grooves and contains the common center of curvature. Astigmatism-corrected designs are obtained for off-plane incidence on the grating if one point on the slit is located on the Rowland circle of the primary mirror. In this case, the combined system of primary mirror plus diffraction grating provides two astigmatic line images oriented parallel and orthogonal to the plane of diffraction, with the former located on the same plane as the slit. Consequently, these images can be brought to a single focus on this plane by the tertiary mirror if its radius of curvature is chosen properly. In addition, coma aberration is simultaneously removed. These results can be applied to the design of two-mirror or three-mirror spectrometers, generalizing the concept of the best imaging circle and providing solutions to get anastigmatic imaging for two object points and two wavelengths.