Elevated CO2 concentration improves functional traits and early growth of the widespread species Enterolobium contortisiliquum (Vell. ) Morong / Elevada concentração de CO2 melhora as características funcionais e o crescimento inicial da espécie generalista Enterolobium contortisiliquum (Vell. ) Morong

Enterolobium contortisiliquum is a neotropical widespread species that occurs in native AtlanticForest, Cerrado and Caatinga vegetation in Brazil. Outside Brazil, it occurs in Argentina, Bolivia, Paraguay, and Uruguay. The objective of this study was to investigate the influence of high carbon dioxide concentration [CO2] on leaf gas exchange, chlorophyll content, chlorophyll a fluorescence, growth, and biomass allocation among roots, stems, and leaves in young plants of E. contortisiliquum. After germination, twenty days old individuals of E. contortisiliquum were grown in open-top chambers (OTC) at two different [CO2] (400 ppm and 700 ppm). Physiological measurements were made when the plants had been grown in OTC for 170, 200, 230, and 260 days. The higher [CO2] favored the early growth of E. contortisiliquum by increasing maximum net photosynthesis (PN) and water use efficiency. Under high [CO2], root dry mass increased in E. contortisiliquum, which might be a trait that will benefit this species by enhancing water uptake, particularly in seasonally dry environments.

Enterolobium contortisiliquum é uma espécie neotropical generalista, encontrada na vegetação nativa da Mata Atlântica do Brasil, no Cerrado e na Caatinga. Fora do país, também pode ser encontrada empaíses como Argentina, Bolívia, Paraguai e Uruguai. O objetivo deste estudo foi investigar a influência da alta concentração de dióxido de carbono [CO2] nas trocas gasosas foliares, no teor de clorofila, na fluorescência da clorofila a, no crescimento e alocação de biomassa entre raízes, caules e folhas em plantas jovens de E. contortisiliquum. Após a germinação, indivíduos de E. contortisiliquum de 20 dias de idade foram cultivados em câmaras de topo aberto (CTA), em duas diferentes [CO2] (400 ppm e 700 ppm). Asmedições fisiológicas foram realizadas no momento do cultivo das plantas em CTA por 170, 200, 230 e 260 dias. A alta [CO2] favoreceu o crescimento inicial de E. contortisiliquum aumentando a fotossíntese líquida máxima (PN) e a eficiência do uso da água. Sob alta [CO2], a massa seca da raiz aumentou em E. contortisiliquum, o que pode ser uma característica que beneficiará esta espécie, aumentando a absorção de água, particularmente em ambientes sazonalmente secos.

Enhancement of pigment extraction from B. braunii pretreated using CO2 rapid depressurization

Abstract Extraction of compounds from microalgae requires cell disruption as a pretreatment to increase extraction yield. Botryococcus braunii is a microalga with a significant content of carotenoids and other antioxidant compounds, such as chlorophylls. Cell disruption of B. braunii using CO2 rapid depressurization was studied as a pretreatment for the extraction of carotenoid and chlorophyll pigments. We studied the effect of temperature (21–49 °C) and pressure (6–13 MPa) during static compression on pigment recovery with supercritical CO2 at 40 °C, 30 MPa and solvent flow of 4.7 L NPT/min. Within the experimental region, the extraction yield of carotenoids and chlorophylls increased by 2.4- and 2.2-fold respectively. Static compression conditions of high pressure and low temperature increased the extraction of carotenoids and especially chlorophylls. We selected 21 °C and 13 MPa as the cell disruption condition, which produced 1.91 g/kg d.s. of carotenoids and 14.03 mg/kg d.s. of chlorophylls. Pretreated microalga gave a 10-fold higher chlorophyll extraction yield compared to the untreated sample. While for carotenoids and tocopherols were 1.25 and 1.14-fold higher, respectively. Additionally, antioxidant activity of pretreated microalga (33.22 mmol TE/kg oil) was significantly higher than the value for the untreated samples (29.11 mmol TE/kg oil) (p ≤ 0.05). Confocal microscopy images showed morphological differences between micro-colonies with and without disruption treatment, suggesting that partial cell disruption by rapid depressurization improved the extraction of microalga compounds.

Presentation of an experimental method to induce in vitro ("organ chambers") respiratory acidosis and its effect on vascular reactivity

PURPOSE: To create in vitro a model to generate acidosis by CO2 bubbling "organ chambers", which would be useful for researchers that aim to study the effects of acid-base disturbs on the endothelium-dependent vascular reactivity. METHODS: Eighteen male Wistar rats (230-280g) were housed, before the experiments, under standard laboratory conditions (12h light/dark cycle at 21°C), with free access to food and water. The protocol for promoting in vitro respiratory acidosis was carried out by bubbling increased concentrations of CO2. The target was to achieve an ideal way to decrease the pH gradually to a value of approximately 6.6.It was used, initially, a gas blender varying concentrations of the carbogenic mixture (95% O2 + 5% CO2) and pure CO2. RESULTS: 1) 100% CO2, pH variation very fast, pH minimum 6.0; 2) 90%CO2 pH variation bit slower, pH minimum6.31; 3) 70%CO2, pH variation slower, pH minimum 6.32; 4) 50% CO2, pH variation slower, pH minimum 6:42; 5) 40 %CO2, Adequate record, pH minimum 6.61, and; 6) 30 %CO2 could not reach values below pH minimum 7.03. Based on these data the gas mixture (O2 60% + CO2 40%) was adopted, CONCLUSION: This gas mixture (O2 60% + CO2 40%) was effective in inducing respiratory acidosis at a speed that made, possible the recording of isometric force. .

Cerebral Oxygenation during Laparoscopic Surgery: Jugular Bulb versus Regional Cerebral Oxygen Saturation

PURPOSE: We hypothesized that regional cerebral oxygen saturation (rSO2) could replace jugular bulb oxygen saturation (SjvO2) in the steep Trendelenburg position under pneumoperitoneum. Therefore, we evaluated the relationship between SjvO2 and rSO2 during laparoscopic surgery. MATERIALS AND METHODS: After induction of anesthesia, mechanical ventilation was controlled to increase PaCO2 from 35 to 45 mm Hg in the supine position, and the changes in SjvO2 and rSO2 were measured. Then, after establishment of pneumoperitoneum and Trendelenburg position, ventilation was controlled to maintain a PaCO2 at 35 mm Hg and the CO2 step and measurements were repeated. The changes in SjvO2 (rSO2) -CO2 reactivity were compared in the supine position and Trendelenburg-pneumoperitoneum condition, respectively. RESULTS: There was little correlation between SjvO2 and rSO2 in the supine position (concordance correlation coefficient=0.2819). Bland-Altman plots showed a mean bias of 8.4% with a limit of agreement of 21.6% and -4.7%. SjvO2 and rSO2 were not correlated during Trendelenburg-pneumoperitoneum condition (concordance correlation coefficient=0.3657). Bland-Altman plots showed a mean bias of 10.6% with a limit of agreement of 23.6% and -2.4%. The SjvO2-CO2 reactivity was higher than rSO2-CO2 reactivity in the supine position and Trendelenburg-pneumoperitoneum condition, respectively (0.9+/-1.1 vs. 0.4+/-1.2% mm Hg-1, p=0.04; 1.7+/-1.3 vs. 0.5+/-1.1% mm Hg-1, p<0.001). CONCLUSION: There is little correlation between SjvO2 and rSO2 in the supine position and Trendelenburg-pneumoperitoneum condition during laparoscopic surgery.

Nocturnal hypoventilation – identifying & treating syndromes.

Nocturnal hypoventilation is a common feature of disorders affecting the function of the diaphragm or central respiratory drive mechanisms. The ensuing change in gas exchange is initially confined to rapid eye movement (REM) sleep, but over time buffering of the raised carbon dioxide produces a secondary depression of respiratory drive that will further reduce ventilation not only during sleep but eventually during wakefulness as well. Failure to identify and treat nocturnal hypoventilation results in impairments in daytime function, quality of life and premature mortality. While some simple daytime tests of respiratory function can identify at risk individuals, these cannot predict the nature or severity of any sleep disordered breathing present. Nocturnal monitoring of gas exchange with or without full polysomnography is the only way to comprehensively assess this disorder, especially in the early stages of its evolution. Non invasive ventilation used during sleep is the most appropriate approach to reverse the consequences of nocturnal hypoventilation, although continuous positive airway pressure (CPAP) may be effective in those individuals where a significant degree of upper airway obstruction is present. When appropriately selected patients use therapy on a regular basis, significant improvements in quality of life, exercise capacity and survival can be achieved, irrespective of the underlying disease process.

Cultivo contínuo de Arthrospira (Spirulina) platensis em fotobiorreator tubular utilizando uréia como fonte de nitrogênio e CO2 puro ou proveniente de fermentação alcoólica / Continuous cultivation of Arthrospira (Spirulina) platensis in tubular photobioreactor using urea as nitrogen source and CO2 from cylinder or produced by alcoholic fermentation

A aplicabilidade do processo de produção de microrganismos fotossintetizantes depende da obtenção de altas concentrações de biomassa e para isso seria interessante o emprego de fotobiorreatores tubulares. Eles permitem redução da área de cultivo e menor perda de CO2 e nitrogênio amoniacal por volatilização. Em uma primeira etapa deste trabalho, Arthrospira platensis foi cultivada por processo contínuo, avaliando-se diferentes valores de vazão específica de alimentação (D = 0,2 a 1,0 dia-1) e diferentes intensidades luminosas (I = 60 e 120 µmol fótons.m-2.s-1). Verificou-se que 120 µmol fótons.m-2.s-1 associada a D igual a 0,2 dia-1 resultou em maior valor de concentração celular em regime permanente (XP = 2446 ± 74 mg.L-1.d-1), mas o mesmo I associado a maior valor de D (0,6 dia-1) levou ao melhor valor de produtividade em células (PX = 938,73 mg.L-1.d-1). Foi possível a obtenção do regime permanente em quase todos os ensaios, o que indica que o cultivo contínuo de A. platensis em fotobiorreator tubular, usando uréia como fonte de nitrogênio, pode levar a resultados satisfatórios. Considerando a preocupação em relação à substituição de combustíveis fósseis por biocombustíveis, é iminente o crescente aumento da produção de etanol ainda nos próximos anos, e esse trabalho propõe o uso do CO2 liberado pela fermentação alcoólica na produção de microrganismos fotossintetizantes como A. platensis. Para isso, em uma segunda etapa, A. platensis foi cultivada por processo contínuo, com I igual a 120 µmol fótons.m-2.s-1, empregando uréia e CO2 proveniente de fermentação alcoólica para manutenção de pH e reposição da fonte de carbono. O uso desse CO2, sem tratamento prévio, associado a D igual a 0,6 dia-1 e concentração de uréia de 3,2 mM no meio de alimentação, permitiu a obtenção de PX igual a 839 ± 25 mg.L-1.d-1, o que está próximo de 938 ± 30mg.L-1.d-1, obtido com CO2 puro de cilindro. Estes resultados mostram que o uso de CO2 de fermentação alcoólica, associado a...

Appropriately designed tubular photobioreactors seem to be suitable for photosynthetic biomass production. It can reduce the cultivation area and provide lower loss of CO2 and ammoniacal nitrogen by volatilization. In a first step of this study, Arthrospira platensis was cultivated by continuous process, testing different values of dilution rate (D = 0.2 to 1.0 d-1) and light intensities (I = 60 and 120 µmol photons.m-2.s-1). The results of these runs showed that the maximum steady-state cell concentration (XS = 2446 ± 74 mg.L-1.d-1) was achieved at 120 µmol photons.m-2.s-1 and D of 0.2 d-1, but the same light intensity associated to higher dilution rate (0.6 d-1) provided the highest cell productivity (PX = 938 ± 30 mg.L-1.d-1), a value appreciably higher than that reported in other studies. Besides, steady-state conditions were achieved in most of the runs indicating that A. platensis continuous cultivation in the tubular photobioreactor, using urea as nitrogen source, can be performed effectively, thus appearing an interesting alternative for the large scale fixation of carbon dioxide to mitigate the green house effect. Taking into account the concern about the substitution of fossil fuel with biofuels, its evident that the ethanol production is going to increase even more in the next years, and this study propose the use of the CO2 released by the alcoholic fermentation for the production of photosynthetic microorganism such as A. platensis. For this purpose, in a second step, cultivations of A. platensis were carried out with 120 µmol photons.m-2.s-1 by continuous process, using urea and CO2 from Alcoholic fermentation for pH maintenance and carbon source replacement. The use of this CO2, without any treatment, associated with a D of 0.6 d-1 and feed urea concentration of 3.2 mM provide us a PX of 839 ± 25 mg.L-1.d-1, which is slightly lower than 938 ±30 mg.L-1.d-1, obtained with pure CO2 from cylinder. Our results showed that the use of CO2 from...

Carbon dioxide reforming of methane on Ni/CaO-AI2O3 catalysts

NiO/AI2O3 and NiO/CaO-AI2O3 samples were prepared and calcined at 700-900°C. Characterization of these samples was made using X-ray diffraction, low temperature nitrogen adsorption, thermal programmed reduction [TPR] and chemisorption of hydrogen at 700°C. The samples were reduced and the initial catalytic methane reforming activities were determined at 700°C. The crystalline phases in each catalyst and their domination as well as textural properties of the catalysts depend on the chemical composition and calcination temperatures. The thermal programmed desorption profiles and the chemisorption of hydrogen depend on the chemical composition of the catalysts and their calcinations temperature. Hydrogen chemisorption allowed the determination of important catalytic parameters which play dominant roles in determining the initial activity of these catalysts toward methane reforming to synthesis gas by carbon dioxide at 700°C

Off-flavors removal and storage improvement of mackerel viscera by supercritical carbon dioxide extraction.

The oil in mackerel viscera was extracted by supercritical carbon dioxide (SCO2) at a semi-batch flow extraction process and the fatty acids composition in the oil was identified. Also the off-flavors removal in mackerel viscera and the storage improvement of the oils were carried out. As results obtained, by increasing pressure and temperature, quantity was increased. The maximum yield of oils obtained from mackerel viscera by SCO, extraction was 118 mgg(-1) (base on dry weight of freeze-dried raw anchovy) at 50 degrees C, 350 bar And the extracted oil contained high concentration of EPA and DHA. Also it was found that the autoxidation of the oils using SCO2 extraction occurred very slowly compared to the oils by organic solvent extraction. The off-flavors in the powder after SCO2 extraction were significantly removed. Especially complete removal of the trimethylamine which influences a negative compound to the products showed. Also other significant off-flavors such as aldehydes, sulfur-containing compounds, ketones, acids or alcohols were removed by the extraction.

Protein properties of mackerel viscera extracted by supercritical carbon dioxide.

The extraction of mackerel viscera using supercritical carbon dioxide (SCO2) was performed under the conditions of temperature range from 35 to 45 degrees C, and constant pressure 25 MPa. The digestive enzyme activities were determined in comparison of untreated and treated SCO2 and solvent treatment. Activities were maintained with high level compared to that of solvent extraction. Also from result of SDS-PAGE, the protein denaturation was minimized when using SCO2 extraction. The major amino acids in the mackerel viscera were determined as glutamic acid, aspartic acid, glycine, leucine, lysine and the free amino acids were taurine, L-alanine, L-leucine, 1-methyl-L-histamine, 3-methyl-L-histidine.

Nutrient dynamics and decomposition rates during composting of sulphitation pressmud by different methods.

Decomposition rates and nutrient contents of sulphitation pressmud (SPM), either alone or by mixing with cow dung and rice straw, under the aerobic (heap and NADEP), anaerobic (pit) and vermicomposting methods were compared. Loss in Organic C and C/N ratios of the decomposing materials indicated the heap and NADEP methods faster for the composting of SPM alone and SPM + cow dung and vermicomposting method for SPM + rice straw registering significant reductions in Organic C ranging from 45.0 to 61.0% from the respective decomposing materials at termination time (119 days). The heap and NADEP methods recorded C/N ratio of SPM alone as low as 11 and 12 and SPM + cow dung as 12.0 and 13.9 at termination stage. Vermicomposting method brought the C/N ratio of SPM + rice straw to 16.4 as compared to 18.6 to 29.8 with the other methods. Irrespective of the composting methods, CO2 evolution from the decomposing materials was higher in early period (up to 28 days). Among methods, NADEP and heap methods recorded more CO2 evolution in early period while vermicomposting method showed more CO2 evolution at the later intervals in comparison to the other methods. Nutrient content in the decomposing materials at different intervals depended on their initial contents. Total N in the composts were statistically comparable, however, the composts of SPM alone recorded relatively more N than SPM + cow dung and SPM + rice-straw prepared by the respective methods. Total P and K contents of the composts increased with time irrespective of the composting methods. Composts of SPM alone recorded significantly more total P than SPM + cow dung and SPM + rice straw at 62, 91 and 119 days while SPM + rice straw recorded more total K than the composts of other materials. Total P in the composts did not differ with the composting methods, but total K in composts of SPM alone was relatively more with heap and NADEP methods, in SPM + cow dung with pit method and in SPM + rice straw by vermicomposting method. Total S in the composts decreased with time and both the aerobic methods showed more reductions than pit and vermicomposting methods.

The Reflex Effects on the Respiratory Regulation of the CO2 at the Different Flow Rate and Concentration

PURPOSE: The purpose of this study was to investigate the activation of the respiratory centers during insufflation of the larynx with CO2 at different flow rates and concentrations. MATERIALS AND METHODS: The experiments were carried out in spontaneous air breathing rabbits, anesthetized with thiopental sodium (25mg kg(-1) i.v.). The larynx was separated from the oropharyngeal cavity and the trachea. The tidal volume (VT) and respiratory frequency (f min(-1)) were recorded from the lower tracheal cannula. The respiratory minute volume (VE) was calculated, the action potentials from the right phrenic nerve were recorded and the inspiratory (TI) and expiratory (TE) periods and the mean inspiratory flow rate (VT/TI) were calculated. The larynx was insufflated at flow rates of 500mL min(-1) and 750mL min(-1), with 7 and 12% CO2-Air by means of a respiratory pump. RESULTS: Insufflation of the larynx, with both gas mixtures, decreased the f and VT significantly. The TI and TE were found to increase significantly due to the decreasing in f. There was a significant decrease in VT/TI ratio. Following bilateral midcervical vagotomy, on the passing of both gas mixtures, significant decreases were observed in the VT, and the responses of f, TI and TE were abolished. After cutting the superior laryngeal nerve, the responses of the VT to both gas mixtures were abolished. CONCLUSION: In conclusion, the results of this study purpose that the stimulation of the laryngeal mechanoreceptors by the effect of hyper- capnia decreases the activation of the respiratory center

Como evitar a formação de substâncias tóxicas durante a absorção de dióxido de carbono pela cal sodada com uso de anestésicos halogenados / Preventing toxic substances production during carbon dioxide absorption by soda lime with halogenate anesthetics

JUSTIFICATIVA E OBJETIVOS: A cal sodada desde o início do seu uso sempre apresentou algumas complicações que resultaram em dificuldade na sua aplicabilidade. No entanto, devido as grandes vantagens que oferecia em relação a redução do fluxo de gases frescos, despoluição da sala de cirurgia e umidificação do sistema de inalação e via aérea, fizeram com que continuassem as pesquisas para que pudesse ser melhorada e corrigida de forma que a continuidade da sua utilização fosse assegurada. Atualmente existe o problema da desidratação com elevação da temperatura e da degradação metabólica dos anestésicos halogenados que necessitam de cuidados especiais para evitar a formação de produtos tóxicos. CONTEUDO: Existe uma reação em cadeia a partir da cal sodada desidratada ou ressecada com baixos volumes percentuais de água. Há aumento da temperatura, maior absorção de anestésico halogenado para o interior do granulo de cal em seguida maior degradação metabólica das moléculas destes agentes e conseqüentemente a produção de substâncias tóxicas como o Composto A pela reação dos hidróxidos com o sevoflurano. Há também formação de monóxido de carbono produzido da mesma forma pela reação entre os halogenados e as bases fortes da cal. O composto A é nefrotóxico e o monóxido de carbono leva a hipóxia e alterações graves da coagulação do sangue. Além dos cuidados para a hidratação da cal sodada é possível usá-la sem conter as bases fortes como os hidróxidos de potássio e de sódio, contendo apenas hidróxido de cálcio para evitar excessivo aumento da temperatura e grande degradação metabólica dos halogenados sem prejudicar a absorção do dióxido de carbono. CONCLUSÕES: Deve-se ter o cuidado em usar a cal sodada mais recente possível e quando ela fica exposta ao meio ambiente (ar seco) por muitas horas como por exemplo em um final de semana (mais de 48 horas) é recomendável colocar água, de preferência destilada, na relação de 25 ml para cada 500 g de cal. Atualmente a indústria está bem informada sobre o problema da composição da cal, então, deve-se preferir a cal sodada que tenha somente o hidróxido de cálcio e seja totalmente desprovida de hidróxido de potássio e hidróxido de sódio.

Lasers en odontología / Lasers in dentistry

El uso del rayo láser en odontología inició en la década de ;ps 80, principalmente el CO2 y el Nd/YAG (Neodimium/Ytrium-Aluminium-Garnet); su principal uso es en los tejidos blandos en la cavidad bucal, por ejemplo en tratamientos periodontales, en excisión de fibromas, etc., así como también el Er/YAG que se utiliza hoy en día para remover caries y perforar estructura dentaria. El uso de láser en odontología tiene sus limitaciones, ventajas y desventajas, así como cualquier otra técnica quirúrgica/operatoria. El entendimiento de las bases de la óptica láser y las reacciones de los tejidos son esenciales. Aún así el operador debe tener conocimiento de las diferentes aplicaciones para tratamiento

Rayo láser en periodoncia / Laser in periodontics

Este trabajo tiene la finalidad de promover el conocimiento del uso del láser en periodoncia, sus propiedades físicas, tipos de rayos láser actualmente disponibles y sus efectos de accón sobre tejidos orales y posibilidades de aplicación clínica. Los rayos láser más usados en odontología son el de dióxido de carbono (CO2) y el de neodymium:yttrium-aluminium-garnet (Nd:YAG), para una amplia variedad de procedimientos quirúrgicos, control de la microflora subgingival sobre la superficie radicular, donde se demostró efectos significativos

Usos del rayo láser en odontología restauradora: primera parte: aspectos generales, clasificación, interrelación con los tejidos vivos y precauciones en el uso / Uses of laser in restorative dentistry: first part: general aspects, classification, inter-relationship with living tissues and precautions in using it

Con este artículo se pretende dar comienzo a una serie de publicaciones para así plasmar todo lo relacionado con el uso de la tecnología Laser en la odontología restauradora. En este primer artículo leerá sobre los antecedentes y fundamentos físicos del rayo laser, la clasificación y tipos de laser disponibles para área de la odontología, su interrelación con los tejidos vivos, así como las precauciones a tomar durante su uso. En las siguientes publicaciones de esta serie leeremos las particularidades de cada tipo de rayo laser que es utilizado en la odontología restauradora