10,411 research outputs found
A Unified Model For Developmental Robotics
We present the architecture and distributed
algorithms of an implemented system called
NeuSter, that unifies learning, perception and action
for autonomous robot control. NeuSter comprises
several sub-systems that provide online
learning for networks of million neurons on machine
clusters. It extracts information from sensors,
builds its own representations of the environment
in order to learn non-predefined goals
Ácidos orgânicos e seus efeitos na dessorção de metais pesados em solo contaminado
Phytoremediation of heavy metals is a biotechnology that extracts metals from soils and transfer them to plant. As hyperaccumulator species have demonstrated low potential for commercial phytoextraction, synthetic chelates have been successfully used to induce accumulation of metals by high-biomass plants. However, they pose serious environmental drawbacks regarding excessive amount of metals solubilized. In search for synthetic chelate-alternatives, this paper evaluate the performance of DTPA, EDTA, citric acid, oxalic acid, vanillic acid, and gallic acid in desorbing Cd, Pb, Zn, Cu, and Ni from soil. DTPA and EDTA were highly effective in desorbing Cd, Pb, Zn, Cu, and Ni from soil. However, the excessively high concentration of metals brought in solution by such chelates limits their application in the field. Citric and oxalic acids desorbed substantial quantities of Zn, Cu, and Ni if applied at 10 or 20 mmol kg-1. At the 20 mmol kg-1 dose, vanillic and gallic acids solubilized significant amounts of Zn, Ni, and Cd from soil. None of the tested low molecular weight organic acids substantially increased the Pb concentration in soil solution.Fitoremediação de metais pesados é uma biotecnologia que usa plantas para extrair metais pesados de solos e transferi-los para a parte aérea. Como espécies naturalmente hiperacumuladoras de metais têm demonstrado baixo potencial para fitoextração comercial, agentes quelantes sintéticos são utilizados para induzir acumulação de metais em plantas de alta produção de biomassa. Esses quelantes, entretanto, apresentam a limitação ambiental de solubilizarem quantidades excessivamente altas de metais. Em busca de alternativas para o uso de quelantes sintéticos, o trabalho avaliou a capacidade de seis quelantes (DTPA, EDTA, ácido cítrico, ácido oxálico, ácido vanílico e ácido gálico) na dessorção de Cd, Pb, Zn, Cu e Ni de um solo contaminado. DTPA e EDTA foram eficientes na dessorção de Cd, Pb, Zn, Cu e Ni. No entanto, a alta solubilização de metais provocada por esses ácidos limita sua aplicação em condições de campo. Os ácidos cítrico e oxálico desorveram quantidades substanciais de Zn, Cu e Ni quando aplicados nas doses de 10 e 20 mmol kg-1. Os ácidos vanílico e gálico na dose de 20 mmol kg-1 desorveram significantes quantidades de Zn, Ni e Cd do solo. Nenhum dos ácidos naturais estudados foi eficiente na dessorção de Pb do solo
Fitoextração: uma revisão sobre disponibilidade induzida e acumulação de metais em plantas
Phytoextraction has emerged as a novel approach to clean up metal-polluted soils in which plants are used to transfer toxic metals from soils to shoots. This review provides a synthesis of current knowledge on phytoextraction of metals from soils and their accumulation in plants. The objective is to integrate soil-related (root exudates and chemical amendments) and biological advances to suggest research needs and future directions. As far as can be deduced from the literature, it will be some time before phytoextraction may be established as a commercial technology. For chemically-assisted phytoextraction, research has not shown easily biodegradable compounds to overcome the risks associated with the use of EDTA for poorly available metals in soils. On the other hand, significant progress has been made on the physiological and molecular aspects regarding tolerance and phytoaccumulation of metals in plants. A multidisciplinary approach is warranted to make phytoextraction a feasible commercial technology to remediate metal-polluted soils.A fitoextração é uma tecnologia emergente para despoluição de solos contaminados por metais pesados que usa plantas para transferir metais do solo para a parte aérea, a qual pode ser removida da área poluída. Esta revisão apresenta uma síntese do atual conhecimento sobre fitoextração de metais pesados do solo e sua acumulação em plantas. O objetivo é integrar em uma mesma discussão os avanços relacionados à química do solo (exsudação radicular e adição de agentes quelantes para aumentar a absorção) e à biologia (tolerância a metais e melhoramento genético) visando sugerir futuras pesquisas na área. Embora promissor, o atual estado de desenvolvimento da fitoextração ainda não permite estabelecê-la como uma tecnologia comercial. A pesquisa ainda não encontrou agentes quelantes facilmente biodegradáveis que possam substituir o EDTA na solubilização de metais pouco disponíveis em solos. Entretanto, significativos progressos têm sido feitos no entendimento dos mecanismos fisiológicos e moleculares de tolerância e acumulação de metais em plantas. Uma abordagem multidisciplinar dos vários aspectos que envolvem a fitoextração poderá tornar essa tecnologia econômica e ambientalmente viável a médio prazo
Near-Infrared Variability Study of the Central 2.3 arcmin x 2.3 arcmin of the Galactic Centre I. Catalog of Variable Sources
We used four-year baseline HST/WFC3 IR observations of the Galactic Centre in
the F153M band (1.53 micron) to identify variable stars in the central
~2.3'x2.3' field. We classified 3845 long-term (periods from months to years)
and 76 short-term (periods of a few days or less) variables among a total
sample of 33070 stars. For 36 of the latter ones, we also derived their periods
(<3 days). Our catalog not only confirms bright long period variables and
massive eclipsing binaries identified in previous works, but also contains many
newly recognized dim variable stars. For example, we found \delta Scuti and RR
Lyrae stars towards the Galactic Centre for the first time, as well as one BL
Her star (period < 1.3 d). We cross-correlated our catalog with previous
spectroscopic studies and found that 319 variables have well-defined stellar
types, such as Wolf-Rayet, OB main sequence, supergiants and asymptotic giant
branch stars. We used colours and magnitudes to infer the probable variable
types for those stars without accurately measured periods or spectroscopic
information. We conclude that the majority of unclassified variables could
potentially be eclipsing/ellipsoidal binaries and Type II Cepheids. Our source
catalog will be valuable for future studies aimed at constraining the distance,
star formation history and massive binary fraction of the Milky Way nuclear
star cluster.Comment: has been accepted to be published in MNRAS, 64 pages, 26 figures. The
complete lists of table 3, 4, 8 and 9 will be published onlin
Factors associated with attendance at the postpartum blood pressure visit in pregnancies complicated by hypertension.
OBJECTIVES: Women with hypertensive disorders of pregnancy should have a blood pressure evaluation no later than 7-10 days after delivery. The objective of this study was to identify the factors associated with patient attendance at the postpartum blood pressure follow-up visit.
STUDY DESIGN: This was a retrospective cohort study of postpartum women who had a hypertensive disorder of pregnancy. Postpartum follow-up rates were recorded, and characteristics of women who attended a postpartum visit for blood pressure evaluation were compared to women who did not return for the visit. Multiple logistic regression was performed.
MAIN OUTCOME MEASURES: Characteristics of women who returned for a blood pressure visit.
RESULTS: There were 378 women who met inclusion criteria; 193(51.1%) attended the blood pressure visit. Women who returned were older and more likely to have preeclampsia, severe features, magnesium sulfate use, or severe hypertension during hospitalization. They were less likely to have gestational hypertension. Adjusted analysis demonstrated that black/non-Hispanic women (OR 0.53, 95% CI 0.34-0.83), the presence of any preeclampsia diagnosis (OR 2.19, 95% CI 1.03-4.81), and whether the woman underwent a cesarean delivery (OR 3.06, 95% CI 1.85-5.14) remained significant factors in predicting adherence.
CONCLUSIONS: Women who returned for a blood pressure visit were more likely to have had significant hypertensive disease or a cesarean delivery. Non-Hispanic black women had the lowest rate of follow-up. Given black women have the highest rates of maternal morbidity and mortality nationwide, effective interventions to increase follow-up for them are needed
A Review of Organ/Tissue Donation in Out of Hospital Cardiac Arrest Patients at an Academic Community Hospital
A Review of Organ/Tissue Donation in Out of Hospital Cardiac Arrest Patients at an Academic Community Hospital
Jordan Williams, Amanda Broderick, Alexandra Maryashina, James Wu, MD
Department of Surgery, Division of Cardiothoracic Surgery
Abstract
Objective This study sought to review organ/tissue donation statistics in out of hospital cardiac arrest patients.
Background While OHCA patients who are not revived in the emergency department are generally disqualified from donating organs, these patients are sometimes still able to donate tissue. However the fact remains that there is an organ shortage in the United States healthcare system as the need exceeds the donation rate, and thus other avenues to increase the donation rate need to be explored.
Methods A retrospective chart review was performed on 378 patient records with OHCA from January 2011 to May 2015. From these records, the eligibility of the patients to donate, reasons behind their ineligibility, number of patients who donated, reasons for eligible patients who didn’t donate, and a comparison of number of arrests and number of donations by age were extracted.
Results It was found that while 72% of patients were eligible to donate, only 41% of these patients went on to donate tissue and/or organs. For those patients that were ineligible the most common reason was being medically unsuitable, and for the eligible patients who didn’t donate the most common reason was their family withholding consent. In the age comparison of number of arrest and number of organ/tissue donations it was found that the rates by which these groups changed did not match, especially in patients over the age of 50.
Conclusion While no formal conclusion can necessarily be drawn from this data, it does offer some suggestions and ideas for further research. One possible area of study could be increasing education about organ donation in the community surrounding the hospital. Another area of study could be in ways of lengthening organ viability time in OCHA patients that proceed to donate.
Keywords
Out of Hospital Cardiac Arrest, Organ Donation, ECMO, “Education in Organ Donation”
Introduction
The national survival to discharge rate in out of hospital cardiac arrest (OHCA) remains low, currently 9.5% as of 2013 according to the American Heart Association (American Heart Assocation, 2012). One potential solution to this problem might be extracorporeal membrane oxygenation (ECMO) for these patients assuming they match certain criteria such as age, comorbidities, presenting rhythm, time to advanced care, etc. However, another aspect of ECMO could be to prolong organ viability in potential organ donors (Magliocca, et al., 2005) (Munjal, et al., 2012).
According to the US Organ Procurement and Transplantation Network, the percent of national eligible deaths that resulted in donation of at least one organ was 71.3% in 2013 (U.S. Department of Health and Human Services, 2015). However, the amount of organs available for transplant currently does not meet the demand. For example, at the end of 2013 there were 60,189 candidates on the waiting list for a kidney transplant, while there were only 17,654 transplants performed that year. Similar trends were noted for liver, heart, and lung donations (U.S. Department of Health and Human Services, 2015).
Current US organ donation policy on deceased donors states that organ donation can only be considered when the potential donor has died from neurological death or controlled circulatory death (Wall, Plunkett, & Caplan, 2015). OHCA patients that are not successfully revived in the emergency department are considered to have died from an uncontrolled form of death, and thus many of these patients are only eligible to donate tissue (instead of organs). However, an OHCA patient could go on to become a donor if they are revived in the field, or in the emergency department, and are subsequently taken off life continuing measures such as ventilators, ECMO, etc., as this would now be considered a controlled form of circulatory death or neurological death if applicable. Even in a case where a patient has died from a controlled form of death, and is eligible to donate organs and/or tissue, a donation might not occur due to the family of the patient withholding consent. Legislation, such as the revised Uniformed Anatomical Gift Act of 2006, has been introduced which would eliminate the need to gain consent from the family, if the patient in question was listed in their state’s donation registry. However it has not been enacted in Pennsylvania, along with Delaware, Florida and New York (Uniform Law Commission, 2015). This study stands to serve as a review of organ/tissue donation information at an academic community hospital in order to generate interest for further research investigating ways to increase organ donation rates.
Methods
A retrospective chart review was utilized for patients with OHCA over the time period from January 2011 to May 2015. Patients were then sorted by age at time of admission, and were excluded if they were over the age of 70 or under 18, yielding 434 records. An arrest was classified as out of hospital if it occurred before arrival in the emergency department, or occurred in the emergency department. A database was created which encompassed many aspects of OHCA patients; however this study focused primarily on organ donation information. Specifically, the patients’ eligibility for organ/tissue donation was recorded, as well as the reason for their ineligibility, if applicable. The reasons for ineligibility were gained from the Gift of Life (our hospital’s organ procurement organization) form in the patient’s chart. Other data included were if the patient actually donated, reason(s) for not donating, and the specific tissue and/or organs donated. Based off of this information, patients were then excluded from the study if they did not have both eligibility data, and donation data. From this cohort of 378 patients, descriptive statistics were utilized to depict aspects of patient eligibility and donation information.
Results
Out of the 378 patients studied, 72% (272/378) were eligible to donate (see figure 1). For the other 28% (106/378), 33 patients survived to discharge, leaving 73 patients who were ineligible due to some other reason. The most common reason for their ineligibility was being medically unsuitable, with 48 out of the 73 falling into this category (figure 2). The next most common reason was that the medical examiner/coroner determined that they were ineligible (10/73). Finally being ineligible due to previous drug use (8/73), and being marked as ineligible without any reasoning (7/73) were the least common reasons.
The next point viewed was the percent of eligible patients that actually went on to donate organs/tissue. Out of the 272 eligible patients, only 41% (112 patients) actually went on to donate, leaving 59% (160 patients), who, while eligible, didn’t donate (figure 3). The reason behind the lack of donation was then examined. The most frequent reason was family declining to give consent, with 91 of the 160 patients who were eligible but didn’t donate falling into this category (figure 4). For 65 of the 160 patients, the reasons for not donating were undocumented, 3 out of the 160 didn’t donate due to the hospital staff not gaining consent from the family within the organ viability timeframe, and 1 patient who was previously deemed eligible, was later deemed ineligible to donate.
For those patients that were eligible and donated (112/378), the most common tissue donated was corneas, with 82 patients donating these, and the most common organ was the kidney, with 4 patients donating at least one of these (figure 5). An interesting trend to note is how the number of arrests for a given age group differs from the amount of organ donations in that category (figure 6). The number of arrests peak in the 59-62 years age range, while the number of donations peak in the 51-54 range. This would suggest that the rate at which organ/tissue donations are occurring differs from the rate that OHCA’s are occurring.
Discussion
Due to the fact that this study was done at one academic community hospital, formal conclusions cannot be drawn from this study. However, from this review of 378 OHCA patients, it can still be seen that the number of organ/tissue donations does not match the number of arrests. It can also be seen that the most common reason for eligible patients not donating is that their family did not give consent. While there is a law currently being introduced to the Pennsylvania state government that would remove the need to gain consent from the family if the patient was a known donor, other solutions should be pursued. It has been suggested that education on organ donation may serve to play an important role in increasing organ donation rates (Martinez, et al., 2001). Perhaps the families in this study might have benefited from more education on organ donation, before the sudden event of an OHCA in a loved one. This way they would be able to discuss with their loved one what their wishes were beforehand, to prevent the stressful decision from having to be made suddenly in the hospital setting. Considering that many of the patients in this study would not have been eligible to donate organs simply due to their death being classified as an uncontrolled form of death, further research in this hospital could be pursued in expanding organ donor criteria to include more OHCA patients. Along this line, research could be pursued in using ECMO or other organ preservation measures in OHCA patients in order to increase the rates of organ/tissue donation.
Acknowledgements
James Wu, MD
Hope Kincaid, MPH, CPH
Jane Scott
Lynsey Biondi, MD
Hubert Huang, PhD References
American Heart Assocation. (2012, December 12). Heart Disease and Stroke Statistics-2013 Update. Dallas, Texas, United States. Retrieved from http://www.heart.org/HEARTORG/General/Cardiac-Arrest-Statistics_UCM_448311_Article.jsp
Magliocca, J. F., Magee, J. C., Rowe, S. A., Gravel, M. T., Chenault, R. H., Merion, R. M., . . . Hemmila, M. R. (2005). Extracorporeal Support for Organ Donation after Cardiac Death Effectively Expands the Donor Pool. The Journal of Trauma: Injury, Infection and Critical Care, 1095-1102.
Martinez, J. M., Lopez, J. S., Martin, A., Martin, M. J., Scandroglio, B., & Martin, J. M. (2001). Organ Donation and Family Decision-Making within the Spanish Donation System. Social Science and Medicine, 405-421. doi:10.1016/S0277-9536(00)00345-2
Munjal, K. G., Wall, S. P., Goldfrank, L. R., Gilbert, A., Kaufman, B. J., & Dubler, N. N. (2012). A Rationale in Support of Uncontrolled Donation After Circulatory Determination of Death. The Hastings Center Report , 19-26.
U.S. Department of Health and Human Services. (2015, January ). OPTN/SRTR Annual Data Report 2013. American Journal of Transplantation, 15(S2), 1-13. doi:10.1111/ajt.13202
Uniform Law Commission. (2015). Anatomical Gift Act (2006). Retrieved from UniformLaws: http://uniformlaws.org/Act.aspx?title=Anatomical%20Gift%20Act%20%282006%29
Wall, S. P., Plunkett, C., & Caplan, A. (2015). A Potential Solution to the Shortage of Solid Organs for Transplantation. The Journal of the American Medical Assocation, 313(23). doi:doi:10.1001/jama.2015.5328
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