213 research outputs found
Estimación de la captura de carbono en plantaciones de álamo clon 1-63/51 de la comuna de retiro, región del Maule
58 p.Actualmente en el mundo existe una gran preocupación por el calentamiento de la tierra debido al aumento de las concentraciones de gases de efecto invernadero. Uno de los principales responsables del efecto invernadero es el CO2 en la atmosfera, originado principalmente por las actividades antropicas. Los bosques y plantaciones son unos de los grandes sumideros del CO2, que contribuyen al secuestro de carbono atmosférico por medio de la fotosíntesis y la acumulación de biomasa.
El objetivo del presente estudio fue cuantificar la fijación de carbono en una plantación de álamos del clon I-63/51 presente en la comuna de Retiro, región del Maule. Para la estimación del carbono fijado en las fuentes de la biomasa aérea, raíz, hojarasca y suelo, se utilizaron parcelas circulares de 500 m2. En cada parcela se midieron la altura total del árbol y su diámetro a la altura del pecho (1.3 m).
Dentro de la parcela, se ubicaron subparcelas de 1 m2, donde se tomaron muestras de hojarasca y suelo (profundidad de 0 – 30 cm). Para la estimación de la biomasa aérea, se utilizaron ecuaciones generales. Para el caso de la hojarasca, se estimó la biomasa seca a través del peso húmedo y seco. La biomasa de las raíces, se estimo en base a un porcentaje (24%) con respecto a la biomasa aérea. Para el cálculo de carbono orgánico de la biomasa aérea, hojarasca y raíces, se utilizó un factor de 0.531.
El carbono orgánico del suelo, se determinó en el laboratorio de suelo de la Universidad Austral de Chile. Entre los rodales estudiados, el rodal el Calabozo presentó la mayor cantidad de carbono fijado en sus diferentes fuentes (120.8 tC/ha), siguiéndole el rodal San Juan con 90.1 tC/ha y por último el rodal las Lenguas con 61.1 tC/ha.
El componente fuste representó entre el 67.9 a 73.6 % de carbono almacenado en el sistema, siguiéndole la biomasa de la raíz de 16.4 al 17.6 %, el suelo de 6.6 a 11.6 % y por último la hojarasca de 2.1 a 4.1 %./SUMMARY: Currently in the world, there is a concern for the global warming of the earth, due to the increase in the concentrations of greenhouse gases. One of the main responsible for the greenhouse effect is the dioxide of carbon in the atmosphere, mainly due to human activities. Forests and plantations are one of the large sinks of carbon dioxide, which contributes to the abduction of atmospheric carbon in carrying out their photosynthesis and biomass accumulation. The objective of this study was to quantify the fixation of carbon in a poplar plantation of the clone I-63/51 present at the commune of Retiro, region Maule. For the estimation of the carbon fixed in the component of biomass aerial, root, leaf litter and soil, were used circular plots of 500 m2. In each plot, proceeded to inventory, were measured the total height of the tree and its diameter at breast height (1.3 m). Within the plot a subplot of 1 m2 was located, where samples were taken from leaf litter and soil (depth of 0 - 30 cm). For the estimation of the aerial biomass, were used general equations. In the case of the leaf litter, were estimate by the dry and humid samples. The biomass roots were estimate in base of the 24% of the biomass aerial. For the calculation of organic carbon from the biomass aerial, leaf litter and roots, were estimate by the factor defect of 0.531. Organic carbon in the soil, it was determined in the laboratory of soil of the Universidad Austral de Chile.
Among the stands studied stand the Calabozo presented the greatest amount of carbon fixed in their different sources (120.8 tC/ha), followed by stand San Juan with 90.1 tC/ha and finally the stand the Lenguas with 61.1 tC/has. The component stem represent between 67.9 to 73.6 % of carbon stored in the system, followed by the biomass from the root of 16.4 to 17.6 %, the soil from 6.6 to 11.6 % and finally the leaf litter of 2.1 to 4.1 %
Laparoscopic Sleeve Gastrectomy Improves Reproductive Hormone Levels in Morbidly Obese Males -A Series of 28 Cases
Rezumat Gastrectomia longitudinalã laparoscopicã îmbunãtãåeaete nivelul hormonilor reproductivi la bãrbaåii cu obezitate morbidã -o serie de 28 cazuri Introducere: Bãrbaåii obezi prezintã frecvent reduceri ale hormonilor androgeni ce pot fi modificate dupã scãderea ponderalã obåinutã prin chirurgie bariatricã. Gastrectomia longitudinalã laparoscopicã (GLL) a fost folositã frecvent în ultimul deceniu pentru tratarea obezitãåii severe. Scopul studiului a fost evaluarea modificãrilor hormonilor reproductivi dupã GLL
Early Improvement in Glycemic Metabolism after Laparoscopic Sleeve Gastrectomy in Obese Patients -A Prospective Study
Rezumat Ameliorarea rapidã a metabolismului glucidic dupã gastrectomia longitudinalã laparoscopicã la pacienåii cu obezitate -studiu prospectiv Introducere: Conform Organizaåiei Mondiale a Sãnãtãåii, existau în 2014 peste 600 de milioane de adulåi cu obezitate (mai mult decât dublu faåã de anul 1980) care prezintã un risc crescut de dezvoltare a sindromului metabolic, deci inclusiv pentru diabetul zaharat de tip 2. Datoritã controlului slab glicemic în urma tratamentului conservator al DZ tip 2, chirurgia metabolicã a fost capabilã sã câaetige un rol important în managementul pacientului cu DZ tip 2 aei obezitate, cu remisii sau îmbunãtãåiri semnificative raportate în literatura de specialitate. Obiectiv: studierea efectelor gastrectomiei longitudinale laparoscopice (LSG) asupra metabolismului glucidic la pacienåii cu obezitate, cu sau fãrã DZ tip 2. Metodã: 60 de pacienåi consecutivi, operaåi în spitalul Ponderas pentru obezitate prin gastrectomie longitudinalã laparoscopicã, au fost incluaei într-un studiu prospectiv, în perioada FebruarieMartie 2013. IMC-ul (indicele de masã corporalã), circumferinåã abdominalã aei parametrii glicemici au fost studiaåi pre-operator, la 10 zile aei 6 luni postoperator. Rezultate: controlul glicemic a fost semnificant îmbunãtãåit începând cu ziua 10 postoperatorie. Imbunãtãåiri semnificative statistic au fost notate la 6 luni postoperator în valorile IMCului (p<0.0001), circumferinåa abdominalã (p<0.0001), glicemie (p<0.0001), insulinemie (p<0.0001), peptid C (p<0.0001) aei HOMA. Concluzii: o îmbunãtãåire rapidã a metabolismului glucidic, atât la pacienåii cu obezitate aei DZ tip 2 cât aei la cei fãrã DZ tip 2, se regãseaete înaintea scãderii ponderale semnificative (10 zile postoperator). La 6 luni postoperator, când se asociazã aei o scãdere ponderalã semnificativã, atât pacienåii diabetici cât aei cei nediabetici prezintã o îmbunãtãåire suplimentarã a metabolismului glicemic, care poate susåine ideea ca gastrectomia longitudinalã laparoscopicã este o metodã eficientã pentru tratamentul pacienåilor cu obezitate aei sindrom metabolic. Aceste modificãri benefice pot explica atât remisia DZ tip 2 dar aei prevenåia acestuia la pacienåii cu obezitate supuaei tratamentului chirurgical metabolic. Cuvinte cheie: obezitate, metabolism glucidic, gastrectomie longitudinalã laparoscopicã, remisia aei prevenåia diabetului zaharat tip 2 Abstract Background: according to W.H.O. in 2014 more than 600 million adults were obese, (more than doubled since 1980), and face a major risk for the onset of metabolic syndrome, including T2DM. Due to the poor control of glycemic imbalance for the conservative treatment of T2DM, the metabolic surgery was able to gain an important role in modern management of T2DM, with significant reported improvements or remissions for these patients. Objective: to study the effects of laparoscopic sleeve gastrec- BMI, waist circumference and glycemic parameters were studied at the moment of entering the study, 10 days after surgery and at 6 months follow up. Results: the glycemic control was significantly improved starting with postoperative day 10. Statistically significant improvements were noticed after six months postoperatively in BMI values (p<0,0001), waist circumference (p<0,0001), glycemic levels (p<0,0001), insulin (p<0,0001), C-peptide (p<0,0001) and HOMA. Conclusions: a rapid induced improvement of glucose metabolism in both diabetic and non-diabetic patients occurs before a significant weight loss (POD 10). At 6 months, when associated with an important weight loss, both diabetic and non-diabetic patients present a furthermore improvement in glycemic metabolism, that enables us to consider that sleeve gastrectomy is an efficient method for a sustained improvement in the metabolic status of patients with obesity. These beneficial changes that can explain the remission of T2DM can also explain the prevention of T2DM after metabolic surgery
Frontiers in Precision Medicine IV: Artificial Intelligence, Assembling Large Cohorts, and the Population Data Revolution
Large cohort studies and more recently electronic medical records (EMR) are being used to collect massive amounts of genetic information. Implementation of artificial intelligence has become increasingly necessary to interpret this data with the goal of augmenting patient care. While it is impossible to predict what the future holds, policy makers are challenged to create guiding principles and responsibly roll out these new technologies. On March 22, 2019, the University of Utah hosted its fourth annual Precision Medicine Symposium focusing on artificial intelligence, assembling large cohorts, and the population data revolution. The symposium brought together experts in medicine, science, law and ethics to discuss and debate these emerging issues
Amphotericin B deoxycholate prescription and adverse events in a Chilean university hospital
Amphotericin B deoxycholate is associated with infusion-related toxicity and renal toxicity. Purpose: To evaluate
medical indications of this compound in a tertiary care center, analyze adverse reactions, infusion protocols and outcome of treated patients. Patients and methods: Retrospective analysis of 39 treatments indicated in 33 patients during 2007, exploring indications, infusion protocols and renal protective measures, infusion-related adverse reactions, nephrotoxicity, hypokalemia and outcomes. Results: On average, therapy lasted 12 days (2 to 39) and reached 600 mg of accumulated dose (100 to 1950) respectively. 24-hours infusions were applied in 63.2% of prescriptions and 35.9% received a 4-6 hour infusion schedule. In addition, 36.8% received daily a saline infusion before amphotericin. Adverse reactions were observed in 40% of treatments, predominating fever (25%). Nonetheless, nephrotoxicity was infrequent (9.4%), of low magnitude, only affecting patients without previous renal disease, and not requiring dialysis. Hypokalemia developed in 21.6% of treatments. More than half of medical indications were empirical (59%), for presumed infections either by filamentous fungi or yeasts. In the subgroup with microbiological information, main indications were invasive aspergillosis (15.4% of total), systemic candidiasis (12.8%) or meningeal cryptococcosis (10.3%). A favorable response was registered in 41%, and only 48.5% of patients survived. In a multivariate analysis, only age > 60 years remained as an independent factor for developing infusion-related adverse reactions. In the same manner, a SOFA score > 3 and corticosteroids administration
at the same time than amphotericin B, were independently associated to a fatal outcome. Conclusion: infusion-related adverse reactions are frequent during amphotericin B deoxycholate therapy, but renal toxicity is occasionally observed. Amphotercin B was used mainly as empirical therapy in this study
Acute gastroenteritis caused by a Vibrio cholerae non-O1, non-O139 strain harboring a genetic region homologous to the VpaI-7 pathogenicity island
Pathogenic Vibrio cholerae isolates, the etiologic agents of cholera, generally express one of two O antigens (O1
or O139). Most environmental isolates are nonpathogenic and are referred to as “non-O1, non-O139”. However
some V. cholerae non-O1, non-O139 strains are clearly pathogenic and have caused outbreaks or sporadic cases
of gastroenteritis and extraintestinal infections in humans. We report a case of acute gastroenteritis by a V. cholerae
non-O1, non-O139 harboring a genetic region homologous to a segment of the VpaI-7 V. parahaemolyticus
pathogenicity island.Cepas patogénicas de Vibrio cholerae, el agente causal
del cólera, expresan generalmente uno de dos antígenos
O (denominados O1 u O139). La mayoría de las cepas
ambientales son no patogénicas y corresponden al tipo
denominado “no-O1, no-O139”. Sin embargo, algunas
cepas de este tipo son claramente patogénas y han causado
brotes de gastroenteritis e infecciones extra-intestinales
en humanos. Se reporta un caso clínico de gastroenteritis
aguda causado por una cepa de V. cholerae no-O1, no-
O139 que contiene en su genoma una región homóloga a
un segmento de la isla de patogenicidad VpaI-7 descrita
previamente en V. parahaemolyticus
De novo variants in the RNU4-2 snRNA cause a frequent neurodevelopmental syndrome
Around 60% of individuals with neurodevelopmental disorders (NDD) remain undiagnosed after comprehensive genetic testing, primarily of protein-coding genes1. Large genome-sequenced cohorts are improving our ability to discover new diagnoses in the non-coding genome. Here we identify the non-coding RNA RNU4-2 as a syndromic NDD gene. RNU4-2 encodes the U4 small nuclear RNA (snRNA), which is a critical component of the U4/U6.U5 tri-snRNP complex of the major spliceosome2. We identify an 18 base pair region of RNU4-2 mapping to two structural elements in the U4/U6 snRNA duplex (the T-loop and stem III) that is severely depleted of variation in the general population, but in which we identify heterozygous variants in 115 individuals with NDD. Most individuals (77.4%) have the same highly recurrent single base insertion (n.64_65insT). In 54 individuals in whom it could be determined, the de novo variants were all on the maternal allele. We demonstrate that RNU4-2 is highly expressed in the developing human brain, in contrast to RNU4-1 and other U4 homologues. Using RNA sequencing, we show how 5′ splice-site use is systematically disrupted in individuals with RNU4-2 variants, consistent with the known role of this region during spliceosome activation. Finally, we estimate that variants in this 18 base pair region explain 0.4% of individuals with NDD. This work underscores the importance of non-coding genes in rare disorders and will provide a diagnosis to thousands of individuals with NDD worldwide
High mortality within 90 days of diagnosis in patients with Cushing's syndrome: Results from the ERCUSYN Registry
Objective: Patients with Cushing's syndrome (CS) have increased mortality. The aim of this study was to evaluate the causes and time of death in a large cohort of patients with CS and to establish factors associated with increased mortality. Methods: In this cohort study, we analyzed 1564 patients included in the European Registry on CS (ERCUSYN); 1045 (67%) had pituitary-dependent CS, 385 (25%) adrenal-dependent CS, 89 (5%) had an ectopic source and 45 (3%) other causes. The median (IQR) overall follow-up time in ERCUSYN was 2.7 (1.2-5.5) years. Results: Forty-nine patients had died at the time of the analysis; 23 (47%) with pituitary-dependent CS, 6 (12%) with adrenal-dependent CS, 18 (37%) with ectopic CS and two (4%) with CS due to other causes. Of 42 patients whose cause of death was known, 15 (36%) died due to progression of the underlying disease, 13 (31%) due to infections, 7 (17%) due to cardiovascular or cerebrovascular disease and 2 due to pulmonary embolism. The commonest cause of death in patients with pituitary-dependent CS and adrenal-dependent CS were infectious diseases (n?=?8) and progression of the underlying tumor (n?=?10) in patients with ectopic CS. Patients who had died were older and more often males, and had more frequently muscle weakness, diabetes mellitus and ectopic CS, compared to survivors. Of 49 deceased patients, 22 (45%) died within 90 days from start of treatment and 5 (10%) before any treatment was given. The commonest cause of deaths in these 27 patients were infections (n?=?10; 37%). In a regression analysis, age, ectopic CS and active disease were independently associated with overall death before and within 90 days from the start of treatment. Conclusion: Mortality rate was highest in patients with ectopic CS. Infectious diseases were the commonest cause of death soon after diagnosis, emphasizing the need for careful clinical vigilance at that time, especially in patients presenting with concomitant diabetes mellitus
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