1,584 research outputs found
Chemical investigation of a biologically active schinus molle L. leaf extract
The pepper tree Schinus molle L. is an evergreen ornamental plant belonging to the Anacardiaceae family, native to South America and widespread throughout the world. It has biological activities and is used in folk medicine. This paper aims to contribute to a deeper knowledge of its chemical composition and biological properties. S. molle leaf extracts were obtained by sequential extraction with solvents of different polarities and subsequently tested on the HL-60 human leukaemia cell line to define a possible cytotoxic activity. Among the investigated extracts, the petroleum ether extract revealed a high cytotoxic activity, and its chemical composition was further investigated. By a silica column chromatography, eight fractions were obtained, and their compositions were determined by GC-MS analysis. Compounds and relative abundance differed widely among the fractions; sesquiterpenes resulted the main component and alcoholic sesquiterpenes the most abundant
Dramatic mitigation of capacity decay and volume variation in vanadium redox flow batteries through modified preparation of electrolytes
Electrolyte imbalance caused by the undesired vanadium-ions cross-over and water transport through the membrane is one of the main critical issues of vanadium redox flow batteries, leading to battery capacity loss and electrolytes volume variation. In this work, the evolution of discharged capacity and electrolyte volume variation were firstly investigated adopting commercial electrolyte for hundreds of charge-discharge cycles in vanadium redox flow batteries employing different membranes, varying thickness and equivalent weight. Subsequently, with the support of a 1D physics-based model, the origin of the main phenomena regulating capacity decay and volume variation has been identified and different modifications in the preparation of electrolytes have been proposed. Electrolytes characterized by an equal proton concentration between the two tanks at the beginning of cycling operation turned out to limit capacity decay, while increasing electrolyte proton concentration was effective also in the mitigation of volume variation. The most promising electrolyte preparation combined the effect of high proton concentration and null osmotic pressure gradient between the two tanks: compared to commercial electrolyte this preparation reduced the capacity decay from 47.7% to 20.9%, increased the coulombic efficiency from 96.2% to 98.9% and the energy one from 79.9% to 83.4%, and also implied a negligible volume variation during cycles. The effectiveness of this electrolyte preparation has been verified with different membranes, increasing the range of validity of the results, that could be thus applied in a real system regardless of the adopted membrane
Benford's law: what does it say on adversarial images?
Convolutional neural networks (CNNs) are fragile to small perturbations in
the input images. These networks are thus prone to malicious attacks that
perturb the inputs to force a misclassification. Such slightly manipulated
images aimed at deceiving the classifier are known as adversarial images. In
this work, we investigate statistical differences between natural images and
adversarial ones. More precisely, we show that employing a proper image
transformation and for a class of adversarial attacks, the distribution of the
leading digit of the pixels in adversarial images deviates from Benford's law.
The stronger the attack, the more distant the resulting distribution is from
Benford's law. Our analysis provides a detailed investigation of this new
approach that can serve as a basis for alternative adversarial example
detection methods that do not need to modify the original CNN classifier
neither work on the raw high-dimensional pixels as features to defend against
attacks
Contrato de prestación médica
Fil: Zago, Jorge A. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Contratos Civiles y Comerciales. Buenos Aires, Argentin
The meaning of religious beliefs for a group of cancer patients during rehabilitation
Este estudo exploratório teve o objetivo de identificar como a religião influencia a sobrevivência de um grupo de pacientes oncológicos. Consistiu em estudo de caso etnográfico, com a participação de seis laringectomizados, de ambos os sexos, na faixa etária de 51 a 72 anos, operados de dois a cinco anos. Os dados foram coletados por entrevistas semi-estruturadas e analisados segundo os conceitos de cultura e religião. Sintetizou-se os resultados em três categorias descritivas: a representação moral do câncer, as crenças religiosas na trajetória do câncer e a negociação com a religião para a sobrevivência. O significado que emerge - "a expectativa por uma segunda chance" - enfatiza a importância da religião como parte das redes de apoio que se articulam com o enfrentamento do estigma do câncer, com a expectativa da cura e com as formas de organizar a vida cotidiana, na sobrevivência.La finalidad de este estudio exploratorio fue identificar cómo la religión influencia la supervivencia de un grupo de pacientes oncológicos. Consistió en un estudio de caso etnográfico con la participación de seis laringectomizados, de ambos sexos, con edad de 51 a 72 años, que habían sido operados de dos a cinco años antes. Los datos fueron recogidos por entrevistas semi-estructuradas y analizados según los conceptos de cultura y religión. Sintetizamos los resultados en tres categorias descriptivas: la representación moral del cáncer, las creencias religiosas en el trayecto del cáncer y la negociación con la religión por la supervivencia. El significado que resulta - "la expectativa por una segunda oportunidad" - enfatiza la importancia de la religión como parte de las redes de apoyo que se encadenan con la conciliación con el estigma del cáncer, con la expectativa de cura y con las formas de arreglar la vida cotidiana, en la supervivenvia.The objective of this exploratory study was to identify how religion influences the survival of a group of cancer patients. The study consisted of an ethnographic case with the participation of six laryngectomized male and female patients between 51 and 72 years old, who had been operated on two to five years earlier. Data were collected by semistructured interviews and analyzed on the basis of the concepts of culture and religion. The results were synthesized into three descriptive categories: the moral representation of cancer, religious beliefs about the cancer trajectory, and negotiation with religion for survival. These categories give rise to the meaning "the hope for a second chance", which emphasizes the importance of religion as part of the support networks that articulate with the patient's coping with the stigma of cancer, with the hope for cure, and with the ways of organizing everyday life, during survival
Uso de produtos naturais para proteção de mudas na arborização de pastagens.
Os sistemas de produção convencional têm esgotado os recursos ambientais, o que torna o agroecossistema frágil e insustentável. Sistemas silvipastoris podem ser alternativas viáveis na recuperação de pastagens degradadas. Este estudo foi desenvolvido com o objetivo de avaliar produtos naturais na implantação de espécies arbóreas em pastagens com presença constante de bovinos, sem proteção física das mudas. O experimento foi conduzido na Embrapa Gado de Corte, Campo Grande, MS, no período de 02/02/2005 a 28/03/2005. O delineamento utilizado foi de parcelas subdivididas inteiramente ao acaso, com dez repetições. As parcelas foram: 1) fezes bovinas ao redor da muda, 2) sangue bovino seco, 3) ovo sem casca e 4) testemunha sem proteção. As subparcelas foram cinco especies arbóreas: Myroxylon peruiferum (Bálsamo), Dipteryx alata (Cumbaru), Schizolobium parahyba (Guapuruvu), Genipa americana (Jenipapo) e Mimosa caesalpineaefolia (Sansão do campo). A herbivoria foi intensa em todos os tratamentos. A S. parahyba apresentou taxa de sobrevivência de 72,5%, enquanto 100% das plantas da M. caesalpineafolia morreram. Há indícios de que a maior proteção, embora parcial, foi dada pela aplicação de fezes ao redor da muda. As aspersões de sangue ou de ovo não ofereceram proteção às árvores jovens. A concentração e a freqüência de aplicação das fezes é uma alternativa que merece maiores estudos
Influence of biological maturation on postural control in young soccer players
Biological maturation does not follow a linear development path; the process presents inter- individual differences concerning the timing of psychophysical development. The nonlinear nature of the biological maturation process often results in sudden and rapid modifications that can influence the sensorimotor functions, in particular when the peak height velocity (PHV) is approaching. Static standing balance and postural control are fundamental skills, both for daily living and sport performance, that can be strongly affected by PHV. We examined the influence of biological maturation on the performance of static standing balance, an index for sensorimotor control. Two-hundred and 38 young healthy soccer players (U9 to U17), playing in a sub-\ue9lite club (at least two training sessions and an official match per week), were evaluated. After anthropometric measurement, standing balance was assessed using a baropodometric platform (BTS P-Walk, Italy). Subjects stood barefooted on the platform and were recorded at 20 Hz during two 30-s tests, the first with eyes open and the second keeping eyes closed. Participants were split into six groups based on the Maturity Offset (MO), representing the estimated time to/from the PHV and calculated according to Mirwald et al1. The body center of pressure (CoP) sway area and velocity were calculated. Differences between MO groups were tested using a 2-factor (MO and condition) ANOVA with repeated measures on the condition factor (eyes open/closed). The sway area showed a decreasing trend as the MO increased, in particular in MO<-1.5 was higher than in MO>0.5 (p<0.001). Likewise, CoP velocity presented a similar pattern (p<0.001), with a marked decline in groups with MO>0.5. The results suggest that biological maturation is associated with changes in standing balance control. The reduction of CoP sway area and velocity as the MO increase represents the improved efficiency of the postural control system
Management of perforated diverticulitis with generalized peritonitis. a multidisciplinary review and position paper
La diverticolite perforata è una condizione clinica emergente e la sua gestione è impegnativa e ancora dibattuta. Lo scopo di questo documento di posizione era di rivedere criticamente le prove disponibili sulla gestione della diverticolite perforata e della peritonite generalizzata al fine di fornire suggerimenti basati sull'evidenza per una strategia di gestione. Quattro società scientifiche italiane (SICCR, SICUT, SIRM, AIGO), esperti selezionati che hanno identificato 5 temi clinicamente rilevanti nella gestione della diverticolite perforata con peritonite generalizzata che trarrebbero beneficio da una revisione multidisciplinare. Sono state affrontate le seguenti 5 problematiche: 1) Criteri per decidere tra trattamento conservativo e chirurgico in caso di diverticolite perforata con peritonite; 2) Criteri o sistema di punteggio per scegliere l'opzione chirurgica più appropriata quando è confermata la peritonite diffusa 3); La procedura chirurgica appropriata in pazienti emodinamicamente stabili o stabilizzati con peritonite diffusa; 4) La procedura chirurgica appropriata per i pazienti con peritonite generalizzata e shock settico e 5) Terapia medica ottimale in pazienti con peritonite generalizzata da perforazione diverticolare prima e dopo l'intervento chirurgico. Nella diverticolite perforata la chirurgia è indicata in caso di peritonite diffusa o fallimento della gestione conservativa e la decisione di operare non è basata sulla presenza di aria extraluminale. Se la peritonite diffusa è confermata, la scelta della tecnica chirurgica si basa sui risultati intraoperatori e sulla presenza o il rischio di shock settico grave. Ulteriori fattori prognostici da considerare sono lo squilibrio fisiologico, l'età, le comorbidità e lo stato immunitario. Nei pazienti emodinamicamente stabili, la laparoscopia di emergenza presenta vantaggi rispetto alla chirurgia a cielo aperto. Le opzioni includono resezione e anastomosi, procedura di Hartmann o lavaggio laparoscopico. Nella peritonite generalizzata con shock settico, è preferibile un approccio chirurgico aperto. La resezione non restaurativa e / o la chirurgia per il controllo del danno sembrano essere le uniche opzioni praticabili, a seconda della gravità dell'instabilità emodinamica. La gestione medica multidisciplinare dovrebbe essere applicata con gli obiettivi principali di controllare l'infezione, alleviare il dolore postoperatorio e prevenire e / o trattare ileo postoperatorio. In conclusione, la complessità e la diversità dei pazienti con perforazione diverticolare e peritonite diffusa richiede una strategia personalizzata, che preveda un'accurata classificazione dello squilibrio fisiologico, la stadiazione dell'infezione intra-addominale e la scelta della procedura chirurgica più appropriata.Perforated diverticulitis is an emergent clinical condition and its management is challenging and still debated. The aim of this position paper was to critically review the available evidence on the management of perforated diverticulitis and generalized peritonitis in order to provide evidence-based suggestions for a management strategy. Four Italian scientific societies (SICCR, SICUT, SIRM, AIGO), selected experts who identified 5 clinically relevant topics in the management of perforated diverticulitis with generalized peritonitis that would benefit from a multidisciplinary review. The following 5 issues were tackled: 1) Criteria to decide between conservative and surgical treatment in case of perforated diverticulitis with peritonitis; 2) Criteria or scoring system to choose the most appropriate surgical option when diffuse peritonitis is confirmed 3); The appropriate surgical procedure in hemodynamically stable or stabilized patients with diffuse peritonitis; 4) The appropriate surgical procedure for patients with generalized peritonitis and septic shock and 5) Optimal medical therapy in patients with generalized peritonitis from diverticular perforation before and after surgery. In perforated diverticulitis surgery is indicated in case of diffuse peritonitis or failure of conservative management and the decision to operate is not based on the presence of extraluminal air. If diffuse peritonitis is confirmed the choice of surgical technique is based on intraoperative findings and the presence or risk of severe septic shock. Further prognostic factors to consider are physiological derangement, age, comorbidities, and immune status. In hemodynamically stable patients, emergency laparoscopy has benefits over open surgery. Options include resection and anastomosis, Hartmann’s procedure or laparoscopic lavage. In generalized peritonitis with septic shock, an open surgical approach is preferred. Non-restorative resection and/or damage control surgery appear to be the only viable options, depending on the severity of hemodynamic instability. Multidisciplinary medical management should be applied with the main aims of controlling infection, relieving postoperative pain and preventing and/or treating postoperative ileus. In conclusion, the complexity and diversity of patients with diverticular perforation and diffuse peritonitis requires a personalized strategy, involving a thorough classification of physiological derangement, staging of intra-abdominal infection and choice of the most appropriate surgical procedure
- …