الملخص
Objetivo: Presentar dos casos de isquemia anastomótica tardía por bevacizumab y compararlo con la literatura actual. Casos clínicos: Se exponen dos pacientes con cáncer de recto metastásico, con manejo neoadyuvante, quirúrgico y adyuvancia que incluye bevacizumab, que presentan complicaciones isquémicas anastomóticas, evidenciadas con endoscopia, imágenes más biopsias dirigidas, resolviéndose en forma quirúrgica y biopsiando sitios perianastomóticos con cambios isquémicos. Discusión: Existe evidencia en la literatura que reporta isquemias y filtraciones anastomóticas tardías con el uso de bevacizumab. Parece prudente considerar y sospechar en forma oportuna esta complicación, especialmente, en pacientes con factores de riesgo. Conclusiones: Se debe considerar eventos isquémicos en territorios quirúrgicos, al uso de Bevacizumab. Mayor hincapié en pacientes con factores de riesgo como malnutrición, irradiación o sexo masculino. Considerar estudio dirigido anastomótico previo al inicio de bevacizumab. Dar relevancia a los tiempos de suspensión y reinicio de bevacizumab para evaluación de posibles complicaciones isquémicas.
Objective: To present two cases of late anastotomotic breakdown by bevacizumab and compare it with the current literature. Case report: Two patients with metastatic rectal cancer, with neoadjuvant, surgical and adjuvant management including bevacizumab, presenting anastomotic ischemic complications, evidenced with endoscopy, images and directed biopsies, surgically resolved and taking biopsy of perianastomotic sites with ischemic changes. Discussion: There is evidence in the literature reporting late anastomotic ischemia and leaks with the use of bevacizumab. It seems prudent to consider and suspect this complication in a timely manner, especially in patients with risk factors. Conclusions: Ischemic events in surgical territories should be considered when using bevacizumab. Greater emphasis on patients with risk factors such as malnutrition, irradiation or male sex. Anastomotic-directed study prior to initiation of bevacizumab should be considered. To highlight bevacizumab suspension and restart times for the evaluation of possible ischemic complications.
الملخص
Abstract Xanthomonas oryzae pv. oryzae (Xoo), a pathogen responsible for rice bacterial leaf blight, produces biofilm to protect viable Xoo cells from antimicrobial agents. A study was conducted to determine the potency of Acacia mangium methanol (AMMH) leaf extract as a Xoo biofilm inhibitor. Four concentrations (3.13, 6.25, 9.38, and 12.5 mg/mL) of AMMH leaf extract were tested for their ability to inhibit Xoo biofilm formation on a 96-well microtiter plate. The results showed that the negative controls had the highest O.D. values from other treatments, indicating the intense formation of biofilm. This was followed by the positive control (Streptomycin sulfate, 0.2 mg/mL) and AMMH leaf extract at concentration 3.13 mg/mL, which showed no significant differences in their O.D. values (1.96 and 1.57, respectively). All other treatments at concentrations of 6.25, 9.38, and 12.5 mg/mL showed no significant differences in their O.D. values (0.91, 0.79, and 0.53, respectively). For inhibition percentages, treatment with concentration 12.5 mg/mL gave the highest result (81.25%) followed by treatment at concentrations 6.25 and 9.38 mg/mL that showed no significant differences in their inhibition percentage (67.75% and 72.23%, respectively). Concentration 3.13 mg/mL resulted in 44.49% of biofilm inhibition and the positive control resulted in 30.75% of biofilm inhibition. Confocal laser scanning microscopy (CLSM) analysis of Xoo biofilm inhibition and breakdown showed the presence of non-viable Xoo cells and changes in aggregation size due to increase in AMMH leaf extract concentration. Control slides showed the absence of Xoo dead cells.
Resumo Xanthomonas oryzae pv. oryzae (Xoo), um patogênico responsável pela influência bacteriana na folha do arroz, produz biofilme para proteger células Xoo viáveis de agentes antimicrobianos. Foi conduzido um estudo para determinar a potência do extrato de folha de Acacia mangium methanol (AMMH) como um inibidor de biofilme Xoo. Quatro concentrações (3,13, 6,25, 9,38 e 12,5 mg/mL) de extrato de folha de AMMH foram testadas quanto à sua capacidade de inibir a formação de biofilme Xoo em uma placa de microtitulação de 96 poços. Os resultados mostraram que os controles negativos tiveram o maior valor de OD do que os outros tratamentos, indicando a intensa formação de biofilme. Isso foi seguido do controle positivo (sulfato de estreptomicina, com concentração de 0,2 mg/mL, e extrato de folha de AMMH, com concentração de 3,13 mg/mL), que não apresentou diferenças significativas nos seus valores OD (1,96 e 1,57, respectivamente). Todos os outros tratamentos com concentrações de 6,25, 9,38, e 12,5 mg/mL não tiveram diferenças significativas nos seus valores OD (0,91, 0,79, e 0,53, respectivamente). Para percentagens de inibição, o tratamento com concentração 12,5 mg/mL apresentou o maior resultado (81,25%), seguido do tratamento em concentrações de 6,25 e 9,38 mg/mL, que não mostraram diferenças significativas na sua percentagem de inibição (67,75 e 72,23%, respectivamente). Concentração 3,13 mg/mL resultou em 44,49% de inibição do biofilme, e o controle positivo resultou em 30,75% de inibição do biofilme. Análise por microscopia confocal de leitura a laser de inibição e separação de biofilme Xoo revelou a presença de células Xoo não viáveis e alterações no tamanho da agregação por causa do aumento na concentração de extrato de folha de AMMH. Slides de controle mostraram a ausência de células Xoo mortas.
الموضوعات
Oryza , Acacia , Plant Diseases , Xanthomonas , Plant Extracts/pharmacology , Biofilms , Methanolالملخص
Both primary biliary cholangitis and Sjögren's syndrome belong to chronic autoimmune epithelitis, and they often occur at the same time. This article reviews the general features, clinical manifestations, serological features, pathogenesis, treatment regimens, and common features of primary biliary cholangitis and Sjögren's syndrome and explores the common pathogenesis of the two diseases, so as to provide ideas for developing new therapies and management strategies for patients.
الملخص
Both primary biliary cholangitis and Sjögren's syndrome belong to chronic autoimmune epithelitis, and they often occur at the same time. This article reviews the general features, clinical manifestations, serological features, pathogenesis, treatment regimens, and common features of primary biliary cholangitis and Sjögren's syndrome and explores the common pathogenesis of the two diseases, so as to provide ideas for developing new therapies and management strategies for patients.
الملخص
Isomers are widely distributed in Chinese herbal medicines,and can be discriminated by energy-resolved mass spectrometry( ER-MS). However,ER-MS was performed through direct injection of reference compounds with syringe pump,which encountered a significant technical barrier for high-throughput and automated measurements. Herein,online ER-MS was conducted using LC-MS platform,and a pair of isomers,kaempferol vs luteolin,were employed as a case study to illustrate and assess the utility of online ER-MS for isomeric discrimination. High-resolution tandem mass spectrometry data of both flavonoids were acquired on LC-QE-Orbitrap-MS,and the fragmentation pathways responsible for the primary fragment ions were proposed. The primary signal in MS1 occurred at m/z 285( [M-H]-),and the primary signals of either compound generated by retro-Diels-Alder fragmentation were observed at m/z 151 and 133. The spectral information was subsequently transferred onto LC-Qtrap-MS platform to carry out online ER-MS. Two precursor-to-product ion transition candidates were constructed as m/z 285>151 and 285>133,and either afterward derived a set of pseudo-ion transitions( PITs) and so forth,exactly corresponding to a series of progressive collision energies( eg-5,-8,-11 e V,and so on). All PITs were typed into the monitoring list of multiple reaction monitoring program to generate the peak area datasets. Either dataset was normalized using the highest values in the set and imported into Graph Pad Prism software to plot the Gaus-sian-shaped curve that was termed as the break-down graph. The apex of the regressive curve was termed as optimal collision energy( OCE). The OCE values corresponding to m/z 285>151 were calculated as-29. 06 e V and-35. 71 e V for kaempferol and luteolin,respectively. In the case of m/z 285>133,the OCEs were yielded as-44. 15 e V for kaempferol and-49. 01 e V for luteolin. With re-ference to their chemical structures,the location of hydroxyl group was regarded to be responsible for the differences of either m/z 285>151 or 285>133 between the isomers,attributing to their different bond properties. Above all,online ER-MS offers an eligible tool for isomeric discrimination,and provides meaningful information for the accurate chemical composition characterization based on LC-MS,which is not limited to Chinese herbal medicines.
الموضوعات
Chromatography, Liquid , Flavonoids , Kaempferols , Luteolin , Tandem Mass Spectrometryالملخص
Background: It is essential for any health-care facility, regardless of its size, to implement a maintenance programme for medical equipment. The maintenance not only has a positive impact on the safety and effectiveness of healthcare technology, but also increases the lifetime of equipment and thus helps to save scarce investment resources. It also enhances the demand for health services. Demand for services availability is crucial of functioning healthcare technology.Methods: A comprehensive descriptive study of the maintenance of equipment at a tertiary care corporate hospital in India from January 2012 to May 2012. A convenient sampling method was used to capture data from Key Participants which included two categories of staff viz technicians and managers/administrators. There were 40 technicians and 10 managers who responded to the questionnaire. Both the primary and secondary sources of data were used.Results: Breakdown data analysis showed that the major cause of breakdown was human errors. About 40% of breakdown that occurred in the hospital was mainly because of manual errors followed by electrical and mechanical issues. Average down time for the time period of 5 months came to around 19 hours, which was quite high. Analysis of KAP questionnaire showed that about 55% technicians were not having the educational qualification required for handling the medical equipment, about 15% were not given training at the time of purchase of the equipment. Similarly, few managers were not aware about maintenance practices and importance of maintenance management for smooth and efficient functioning.Conclusions: Good and effective maintenance practices can reduce the cost of maintenance of equipment that arises due to breakdown. The training of equipment users and maintenance managers reduces the equipment downtime. To reduce the possibility of equipment malfunction following service or repair, all personnel involved in maintaining and servicing equipment should be trained.
الملخص
Laser-induced breakdown spectroscopy (LIBS) is a sensitive optical technique that is capable of rapid multi-elemental analysis. The development of this technique for elemental analysis of pharmaceutical products may eventually revolutionize the field of human health. Under normal circumstances, the elemental analysis of pharmaceutical products based on chemical methods is time-consuming and complicated. In this investigation, the principal aim is to develop an LIBS-based methodology for ele-mental analysis of pharmaceutical products. This LIBS technique was utilized for qualitative as well as quantitative analysis of the elements present in Ca-based tablets. All the elements present in the tablets were detected and their percentage compositions were verified in a single shot, using the proposed instrument. These elements (e.g., Ca, Mg, Fe, Zn, and others) were identified by the wavelengths of their spectral lines, which were verified using the NIST database. The approximate amount of each element was determined based on their observed peaks and the result was in exact agreement with the content specification. The determination of the composition of prescription drug for patients is highly important in numerous circumstances. For example, the exploitation of LIBS may facilitate elemental decomposition of medicines to determine the accuracy of the stated composition information. Moreover, the approach can provide element-specific, meaningful, and accurate information related to pharmaceutical products.
الملخص
Percutaneous transluminal angioplasty is a well-known treatment for arteriovenous fistula stenosis. Balloon rupture during endovascular procedures is a rare but possible complication. The bursting balloon itself does not cause a serious problem, but it can occasionally cause entrapment, especially in case of breakdown of the balloon catheter tip. Here, we present four cases of balloon rupture during angioplasty in the hemodialysis circuit. In three cases, the ruptured balloon catheter was removed by cutdown of access conduit, while in one case, tip of ruptured balloon catheter was migrated into the pulmonary artery and was removed surgically. The operator must attempt to reduce the risk of balloon rupture by gradually expanding the balloons under bursting pressure. If the balloon bursts, it should not be removed excessively and attempt should be made to remove it using endovascular techniques. Surgical removal is considered after careful evaluation of the condition of the balloon and vessel.
الموضوعات
Angioplasty , Arteriovenous Fistula , Catheters , Constriction, Pathologic , Embolism , Endovascular Procedures , Pulmonary Artery , Renal Dialysis , Ruptureالملخص
Abstract Macroinvertebrate shredders have been widely recognized as an important functional feeding group that contributes to leaf decomposition in temperate streams, but little is known about their role in upland Neotropical streams. In this study, we investigated the effect of macroinvertebrate exclusion on leaf breakdown rates in two upland streams in Colombia. The study was carried out between January and April of 2009, including the dry season and the beginning of the wet season. We measured leaf mass loss using coarse- (15 mm; accessible to macroinvertebrates) and fine- (200 µm; macroinvertebrates excluded) mesh litter bags that were anchored with wood stakes to the bottom of each stream and recovered after 7, 14, 21, 28, and 56 days. We selected leaves from two dominant plant species and used three leaf treatments: two single species (Palicourea cuatrecasasii and Critoniopsis ursicola) and mixed-species (P. cuatrecasasii and C. ursicola). We compared leaf breakdown rates between the Peña Bonita and Marianela stream, mesh-sizes, and leaf treatments. Macroinvertebrates that colonized the litter bags were measured for density and biomass and categorized in functional feeding groups. In general, there were no significant differences in breakdown rates between the streams and the mesh-sizes. In contrast, leaf breakdown rates had significant differences between all leaf species, where C. ursicola had higher breakdown rates than mixed-species, and P. cuatrecasasii. Macroinvertebrate exclusion did not affect leaf breakdown rates and their assemblages were composed by high densities of collectors (mainly Chironomidae) and few shredders with a large body size. The similar macroinvertebrate colonization between leaf species, the relatively slow breakdown rates, and the shredder scarcity, suggest that leaves were a refractory substrate. Further studies should include leaf species with different nutritional qualities and larger spatial-temporal scales to test the hypothesis of shredder presence and its role on leaf decomposition in upland Colombian streams. Rev. Biol. Trop. 66(1): 457-467. Epub 2018 March 01.
Resumen Los macroinvertebrados fragmentadores han sido ampliamente reconocidos como un importante grupo funcional alimenticio que contribuye a la descomposición de la hojarasca en quebradas del hemisferio norte, pero poco se sabe sobre su papel en quebradas de montaña neotropicales. En el presente estudio investigamos el efecto de la exclusión de los macroinvertebrados sobre las tasas de fragmentación de la hojarasca en dos quebradas de montaña en Colombia. Nuestra hipótesis es que la fragmentación de la hojarasca es mediada principalmente por macroinvertebrados fragmentadores en quebradas de montaña en Colombia. Este estudio fue llevado a cabo entre enero y abril 2009, incluyendo la época seca y el comienzo de la época de lluvias. Se midieron las pérdidas de masa de hojarasca usando bolsas de malla gruesa (15 mm; accesible a macroinvertebrados) y fina (200 µm; macroinvertebrados excluidos); estas fueron atadas con estacas de madera al fondo de cada quebrada y recuperadas transcurridos 7, 14, 21, 28 y 56 días. Se seleccionó hojarasca de dos especies dominantes en los sitios de estudio y se usaron tres tratamientos para las bolsas de hojarasca: Critoniopsis ursicola, Palicourea cuatrecasasii y una mezcla de estas dos especies. Se compararon las tasas de fragmentación de la hojarasca entre las dos quebradas, los dos tipos de malla y las especies de hojarasca. Los macroinvertebrados que colonizaron las bolsas de hojarasca fueron medidos en términos de densidad, biomasa y categorizados en grupos funcionales alimenticios. En general, nuestros resultados no mostraron diferencias significativas en las tasas de fragmentación de la hojarasca entre las quebradas y entre los tipos de malla. En contraste, las tasas de fragmentación presentaron diferencias significativas entre las especies de hojarasca; específicamente, C. ursicola tuvo tasas más altas de fragmentación que las especies mezcladas y que P. cuatrecasasii. Con respecto a los macroinvertebrados, el presente estudio encontró que su exclusión no tuvo un efecto sobre las tasas de fragmentación y los ensamblajes estuvieron compuestos por una alta densidad de recolectores (principalmente de la familia Chironomidae) y pocos fragmentadores con gran tamaño corporal. La colonización similar de macroinvertebrados entre las especies de hojarasca, las relativamente lentas tasas de fragmentación, sugieren que las hojas fueron un sustrato refractario. Futuros estudios deberían incluir especies de hojarasca con diferentes calidades nutricionales y una mayor escala espacio-temporal para estudiar la hipótesis de la presencia de fragmentadores en quebradas de montaña en Colombia.
الملخص
It is one of the necessary work in oil and gas exploration and development to record the logging of different depth cuttings.In this study, a laser induced breakdown spectrometer ( LIBS-Trace) developed by our research group was used for the lithology logging in the field of oil and gas exploration and development.A total of 60 samples from a drilling site in the Southwest China were divided into training set and test set, and then element quantitative analysis model of eight elements of Si, Al, Ca, K, Mg, Mn, Ti and Fe was established based on support vector machine regression ( SVR).The results showed that the mean percentage prediction errors (MPE) predicted by this method were Si 5.68%, Al 7.22%, Ca 7.45%, K 9.76%, Mg 8.79%, Mn 11.9%, Ti 11.4% and Fe 10.4%, which met the requirements of logging work.In addition, according to the logging process and demand, the instrument hardware and software were modified, and the quantitative model integrated in the instrument was optimiZed.The results showed that the algorithm model combined with the instrument could quickly complete the quantitative analysis of rock debris samples, and exhibited potential application value and broad application prospect in oil and gas exploration and development.
الملخص
Laser-induced breakdown spectroscopy (LIBS) was used for analysis of the distribution of S,Mn,Fe,Cr,Mo,Si,Al in a 34CrNiMo6 steel sample cut from a main shaft of wind driven generator.The MnS inclusion area in each ablation craters cover zone was extracted in the way of comparing the metallograph captured by optical microscopy before and after LIBS scanning ablation.The statistic relation between MnS inclusion area and signal intensity of S and Mn was analyzed.The result showed that the abnormal signal of S and Mn occurred at the same position with the existence of MnS inclusion,and their signal intensity showed linear relationship.The abnormal signal of S and Mn were triggered mainly by MnS inclusion.The statistic result also showed linear relationship between signal intensity and MnS inclusion area both for S and Mn.It was possible to determine the inclusion type,size and distribution by analyzing abnormal signal.A simplified ablation model was established to calculate the relation of S and Mn content to MnS inclusion area.The arithmetic result showed a linear relation between the content and MnS inclusion area both for S and Mn.The calculation confirmed the linear relationship between signal intensity and inclusion area observed in experiment.The linear relationship could be interfered by macro-segregation,micro-segregation,deviation in measuring inclusion area,and inclusion spatter in pre-ablation.
الملخص
Laser induced breakdown spectroscopy ( LIBS ) was proposed to rapidly discriminate microbe species. Ten species of microbes were prepared in lab. Filter papers were selected as substrate for enriching bacteria and enhancing the quality of LIBS. The images of plasma were collected by ICCD camera and LIBS spectra were obtained by spectrometers. The results displayed that the images and spectra were different from 10 bacteria. It was demonstrated that this method was feasible to discriminate bacteria species by analyzing image and/or spectroscopy. Furthermore, nine smooth and multiple scattering correction ( MSC) were utilized to preprocess the LIBS full-spectrum data in the wavelength range of 200-420 nm and 560-680 nm. And principal component analysis ( PCA) and PCA-RF ( Random forest) were compared to validate the accuracy of discrimination. The investigation showed that the PCA-RF model coupled with suitable methods in preprocessing data could identify bacteria. The accuracy was 99. 6% for ten species of microbes by evaluating LIBS spectra in training set, and 96. 7% in predicting set. This report indicated that it is feasible to differentiate bacteria species by analyzing LIBS spectra.
الملخص
Resumo Aos 44 anos, após sofrer um colapso em Turim, o filósofo Friedrich Nietzsche recebeu o diagnóstico médico de neurossífilis. Devido à ausência de autópsia em seu corpo, tal diagnóstico médico vem sendo questionado historicamente. Realizou-se a revisão da literatura disponível sobre o diagnóstico médico de Nietzsche. Destacam-se três gêneros patográficos que emergiram sucessivamente como explicações para o colapso de Turim: (1) narrativas sobre a sífilis ("demoníaco-patológicas"); (2) narrativas sobre as psicoses funcionais ("heroico-proféticas"); (3) narrativas sobre outras doenças orgânicas, distintas da sífilis ("científico-realistas"). Estas últimas - que correspondem ao nosso objeto de estudo propriamente dito neste trabalho - empreendem diagnósticos retrospectivos, buscando extrair a "verdade" subjacente à doença e elucidar o "caso Nietzsche". Questionamos tal ímpeto detetivesco, exponenciado atualmente pela "medicina baseada em evidência", e denunciamos seu anacronismo. A sífilis tornou-se um fato científico somente após a morte de Nietzsche. Conclui-se que o diagnóstico por ele recebido mostra-se consistente com a racionalidade médica oitocentista e com o estatuto da sífilis como um fato cultural naquela época.
Abstract At age 44, after suffering a breakdown in Turin, philosopher Friedrich Nietzsche was diagnosed with neurosyphilis. There was no necropsy on his body, so this medical diagnosis has been questioned over the time. We conducted a literature review on the medical diagnosis of Nietzsche, which emphasizes three genres of pathographies that emerged successively as alternatives explanations for Nietzsche's breakdown in Turin: (1) narratives about syphilis ("demoniac-pathological"); (2) narratives about functional psychosis ("heroic-prophetic"); (3) other narratives about organic diseases, other than syphilis ("scientific-realistic"). The latter - which correspond to our study object in this work - undertake retrospective diagnostics, attempting to retrieve the "truth" underlying the disease and elucidate "Nietzsche's affair". We inquire this detective-like impetus, currently taken to the extreme by "evidence-based medicine", and we denounce its anachronism. Syphilis has become a scientific fact only after the death of Nietzsche. We conclude that the diagnosis he received is shown to be consistent with the nineteenth-century medical rationality and the syphilis status as a cultural fact at that time.
الموضوعات
Humans , Evidence-Based Medicine , Neurosyphilis/history , Famous Persons , Italy , Neurosyphilis/diagnosisالملخص
ResumenLas condiciones ecológicas de los ríos altoandinos tropicales estan amenazadas por numerosas actividades humanas que incluyen aquellas derivadas del cambio de la cobertura y uso del suelo de la cuenca. Para su evaluación se han propuesto protocolos que diagnostican el estado de la estructura pero no del funcionamiento de estos ecosistemas fluviales. En este trabajo se propone una herramienta de evaluación adaptada a las condiciones locales, incluyendo la metodología y los valores umbrales, utilizando el proceso de descomposición de la hojarasca como una medida del funcionamiento y salud de los ríos altoandinos del sur del Ecuador. Se seleccionaron 15 tributarios distribuidos en tres microcuencas (Mazán, Llaviuco y Matadero) dentro o en las adyacencias del Parque Nacional Cajas. En cada tributario se incubaron bolsas de descomposición elaboradas con dos tipos de malla (gruesa y fina) para separar la contribución de macroinvertebrados y microorganismos en el proceso. Como substrato vegetal se emplearon hojas de Alnus acuminata y Miconia bracteolata. Las bolsas fueron colocadas en los ríos y mantenidas durante 15, 28 y 64 días. Las tasas de descomposición (-K) fueron obtenidas a partir del período de tiempo en el cual se produjo la pérdida de aproximadamente el 50 % de la masa seca libre de ceniza. En cada período de recolección se determinaron parámetros físicos y químicos. Adicionalmente, se aplicaron los índices de calidad de ribera (QBR-And) y de habitat fluvial (IHF). Para la elaboración de los umbrales de condición funcional se utilizaron las métricas Ktotal y el cociente entre la tasa de descomposición en malla gruesa y malla fina (Kg/Kf). Para probar la sensibilidad de las métricas se emplearon métodos gráficos, Anova de una vía y se calculó la eficiencia discriminativa (ED) de las mismas. Los resultados del análisis de usos y coberturas del suelo revelaron un gradiente de intervención Matadero ≥ Llaviuco > Mazán. La composición de las variables ambientales de las corrientes de la microcuenca Mazán resultaron diferentes con respecto a las de Llaviuco y Matadero, cuyos valores parecen ser más semejantes entre sí. La evaluación de la calidad de ribera mediante el índice QBR-And muestra un gradiente importante desde valores muy bajos en las corrientes de Matadero (27.5), valores medios a altos en Llaviuco (66.5) y valores más altos en los tributarios de Mazán (87). Las tasas de descomposición de la hojarasca de los tributarios de la microcuenca del Río Mazán resultaron significativamente más rápidas que en los tributarios de los Ríos Matadero y Llaviuco para las hojas de A. acuminata pero no para las hojas de Miconia. La métrica Kg/Kf se consideró sensible y suficiente para discriminar los impactos en las áreas estudiadas. Los valores del cociente Kg/Kf resultaron significativamente mayores en Mazán en comparación a Llaviuco y Matadero, que no resultaron diferentes entre sí. Nuestros resultados apoyan la utilización del proceso de descomposición de la hojarasca como una herramienta adecuada para evaluar la condición ecológica funcional, complementando las evaluaciones estructurales, de los ríos altoandinos.
Abstract:The ecological condition of tropical Andean rivers are threatened by many human activities including changes in land use and cover in watersheds. Current protocols diagnose the structural condition of streams but not their function. In this study we proposed an assessment tool using the leaf-litter breakdown as a measure of the functional condition and health of high Andean streams in Southern Ecuador, including methodology and threshold values adapted to local conditions. We selected 15 streams in three micro-basins (Mazán, Llaviuco and Matadero) within or in the vicinity of Cajas National Park where we deployed litterbags for 15, 28 and 64 days. We used two types of mesh (coarse and fine) for the litterbags in order to separate the contribution of macro-invertebrates and microorganisms in the decomposition process and also tested two different leaf substrates: Alder (Alnus acuminata) and Miconia (Miconia bracteolata). In each collection period we determined physical and chemical parameters, applied the riparian quality index (QBR-And) and river habitat index (IHF). Decomposition rates (-k) were determined from the time period at which approximately 50 % ash-free mass would have been lost. We used Ktotal and the ratio of the rate of decomposition between coarse and fine mesh (Kg/Kf) to define the functional condition thresholds. To test the metrics sensitivity we used graphical methods, one-way ANOVA and discriminative efficiency (ED). The analysis of watershed land-use and cover showed a gradient of intervention: Matadero ≥ Llaviuco > Mazán. The composition of the environmental variables of Mazán streams were different with respect to Llaviuco and Matadero, whose values were similar to each other. The QBR-And index showed a significant gradient from very low levels in Matadero (27.5), moderately high values in Llaviuco (66.5) to high values in Mazán (87). Alder leaf-litter breakdown rates were significantly faster in Mazán than in Matadero and Llaviuco streams, while breakdown rates of Miconia were not significantly different among watersheds. The Kg/Kf ratio was significantly higher in Mazán compared to Llaviuco and Matadero, which did not differ. We consider the Kg/Kf metric sensitive enough to discriminate impacts in the studied areas. Our results support the use of the leaf-litter breakdown as an appropriate tool to assess functional ecological condition, complementing the structural assessments of these Andean rivers. Rev. Biol. Trop. 65 (1): 321-334. Epub 2017 March 01.
الموضوعات
Biodegradation, Environmental , Ecosystem , Plant Leaves/metabolism , Rivers/chemistry , Reference Values , Water Quality/standards , Reproducibility of Results , Analysis of Variance , Conservation of Natural Resources/methods , Ecuadorالملخص
The blending end-point determination of Angong Niuhuang Wan (AGNH) is a key technology problem. The control strategy based on quality by design (QbD) concept proposes a whole blending end-point determination method, and provides a methodology for blending the Chinese materia medica containing mineral substances. Based on QbD concept, the laser induced breakdown spectroscopy (LIBS) was used to assess the cinnabar, realgar and pearl powder blending of AGNH in a pilot-scale experiment, especially the whole blending end-point in this study. The blending variability of three mineral medicines including cinnabar, realgar and pearl powder, was measured by moving window relative standard deviation (MWRSD) based on LIBS. The time profiles of realgar and pearl powder did not produce consistent results completely, but all of them reached even blending at the last blending stage, so that the whole proposal blending end point was determined. LIBS is a promising Process Analytical Technology (PAT) for process control. Unlike other elemental determination technologies such ICP-OES, LIBS does not need an elaborate digestion procedure, which is a promising and rapid technique to understand the blending process of Chinese materia medica (CMM) containing cinnabar, realgar and other mineral traditional Chinese medicine. This study proposed a novel method for the research of large varieties of traditional Chinese medicines..
الملخص
Regulation of blood glucose levels and body fat is critical for survival. Leptin circulates freely in blood and controls body weight and food intake mainly through hypothalamic receptors and regulates glucose metabolism in the liver both directly through leptin receptors and indirectly via the hypothalamic receptors of central nervous system. Leptin affects food intake regulation and eventually glucose metabolism, lipometabolism, endocrine and immune functions, reproductive function, adipose tissue metabolism and energy expenditure. Leptin also exerts peripheral effects directly on glucose metabolism and gluconeogenesis. Most of obese human subjects have elevated plasma levels of leptin associated to the size of their total adipose tissue mass. Hence gluconeogenic function may be an essential factor in the regulation of nutritional intake and weight gain. The aim of this review is therefore to identify and module the possible effects of leptin with special application in gluconeogenesis. In addition, this review includes the study of fat consumption and energy expenditure in the body. Specific modulation of leptin receptors and adipose tissues functioning could have important inference on therapeutic strategies.
الملخص
Heavy metal residue in vegetables is a big concern in the whole world.The aim of this work is to explore the effect of multivariable selection on analyzing Cd in Chinese cabbage polluted in lab by collecting the spectra of laser induced breakdown spectroscopy (LIBS) from the samples.At the same time,the actual Cd content in samples was obtained by anodic stripping voltammetry (ASV).The LIBS spectral range in partial least square (PLS) model was screened by standard normal variable transformation (SNV),first derivative (FD),second derivative (SD) and center treatment (CT) for preprocessing spectra and the optimized method was used for the analysis of interval partial least square (iPLS) and synergy interval partial least square (SiPLS).The results indicated that the method of CT was the best as a comparison with PLS,iPLS and SiPLS.And the intervals of wavelength were 214.72-215.82 nm,215.88-216.97 nm and 225.08 -226.35 nm by utilizing the optimized SiPLS.Here the root mean square error of cross validation (RMSECV) between real content and predicted ones was 1.487,the root mean squared error of prediction (RMSEP) was 1.094,the correlation coefficient (R) was 0.9942,and the average relative error (ARE) was 11.60％.The results displayed that LIBS could predict Cd in vegetables by multivariable selection of SiPLS and the accuracy could meet the requirement of rapid and green analysis of Cd in vegetables.
الملخص
Laser-induced breakdown spectroscopy has become a very attractive technique in the field of chemical analysis.The technique utilizes a laser focused on a small spot to create a micro-plasma on the sample surface.In recent years, laser-induced breakdown spectroscopy (LIBS) is a frontier analysis technique in spectrometric analysis, with the advantages such as real-time, online and non-contact analysis.The research and development of various instruments based on this technology has attracted great attention of researchers.In the article, we reviewed the research progress of LIBS instrument from the components and field equipment in recent years, mainly including portable LIBS, handheld LIBS and remote LIBS.
الملخص
There are many noise signals in original laser induced breakdown spectroscopy (LIBS) spectra.To explore the effect of spectral pretreatment on LIBS information by different filter methods, the LIBS spectra of Pb-polluted cabbage in wavelength range of 400.45-410.98 nm was investigated and preprocessed by adjacent averaging, Savitzky-Golay (S-G) and fast Fourier transformation (FFT).Then partial least square (PLS) model was established for evaluating the spectral treatment effect.The result showed that the root mean square error of prediction (RMSEP) and average relative error of S-G method were 0.26 and 3.7%, suggesting a superior smoothing effect than other methods.Experimental results indicated that an appropriate filtering method could help to improve the spectral quality and raise the precision of model checkout.
الملخص
Abstract Xanthomonas oryzae pv. oryzae (Xoo), a pathogen responsible for rice bacterial leaf blight, produces biofilm to protect viable Xoo cells from antimicrobial agents. A study was conducted to determine the potency of Acacia mangium methanol (AMMH) leaf extract as a Xoo biofilm inhibitor. Four concentrations (3.13, 6.25, 9.38, and 12.5 mg/mL) of AMMH leaf extract were tested for their ability to inhibit Xoo biofilm formation on a 96-well microtiter plate. The results showed that the negative controls had the highest O.D. values from other treatments, indicating the intense formation of biofilm. This was followed by the positive control (Streptomycin sulfate, 0.2 mg/mL) and AMMH leaf extract at concentration 3.13 mg/mL, which showed no significant differences in their O.D. values (1.96 and 1.57, respectively). All other treatments at concentrations of 6.25, 9.38, and 12.5 mg/mL showed no significant differences in their O.D. values (0.91, 0.79, and 0.53, respectively). For inhibition percentages, treatment with concentration 12.5 mg/mL gave the highest result (81.25%) followed by treatment at concentrations 6.25 and 9.38 mg/mL that showed no significant differences in their inhibition percentage (67.75% and 72.23%, respectively). Concentration 3.13 mg/mL resulted in 44.49% of biofilm inhibition and the positive control resulted in 30.75% of biofilm inhibition. Confocal laser scanning microscopy (CLSM) analysis of Xoo biofilm inhibition and breakdown showed the presence of non-viable Xoo cells and changes in aggregation size due to increase in AMMH leaf extract concentration. Control slides showed the absence of Xoo dead cells.
Resumo Xanthomonas oryzae pv. oryzae (Xoo), um patogênico responsável pela influência bacteriana na folha do arroz, produz biofilme para proteger células Xoo viáveis de agentes antimicrobianos. Foi conduzido um estudo para determinar a potência do extrato de folha de Acacia mangium methanol (AMMH) como um inibidor de biofilme Xoo. Quatro concentrações (3,13, 6,25, 9,38 e 12,5 mg/mL) de extrato de folha de AMMH foram testadas quanto à sua capacidade de inibir a formação de biofilme Xoo em uma placa de microtitulação de 96 poços. Os resultados mostraram que os controles negativos tiveram o maior valor de OD do que os outros tratamentos, indicando a intensa formação de biofilme. Isso foi seguido do controle positivo (sulfato de estreptomicina, com concentração de 0,2 mg/mL, e extrato de folha de AMMH, com concentração de 3,13 mg/mL), que não apresentou diferenças significativas nos seus valores OD (1,96 e 1,57, respectivamente). Todos os outros tratamentos com concentrações de 6,25, 9,38, e 12,5 mg/mL não tiveram diferenças significativas nos seus valores OD (0,91, 0,79, e 0,53, respectivamente). Para percentagens de inibição, o tratamento com concentração 12,5 mg/mL apresentou o maior resultado (81,25%), seguido do tratamento em concentrações de 6,25 e 9,38 mg/mL, que não mostraram diferenças significativas na sua percentagem de inibição (67,75 e 72,23%, respectivamente). Concentração 3,13 mg/mL resultou em 44,49% de inibição do biofilme, e o controle positivo resultou em 30,75% de inibição do biofilme. Análise por microscopia confocal de leitura a laser de inibição e separação de biofilme Xoo revelou a presença de células Xoo não viáveis e alterações no tamanho da agregação por causa do aumento na concentração de extrato de folha de AMMH. Slides de controle mostraram a ausência de células Xoo mortas.