979 resultados para Ca-2 Release


Relevância:

80.00% 80.00%

Publicador:

Resumo:

The interception of the rainfall by the forest canopy has great relevance to the nutrient geochemistry cycle in low fertility tropical soils under native or cultivated forests. However, little is known about the modification of the rainfall water quality and hydrological balance after interception by the canopies of eucalyptus under pure and mixed plantations with leguminous species, in Brazil. Samples of rainfall (RF), throughfall (TF) and stemflow (SF) were collected and analyzed in pure plantations of mangium (nitrogen fixing tree -NFT), guachapele (NFT) and eucalyptus (non-nitrogen fixing tree -NNFT) and in a mixed stand of guachapele and eucalyptus in Seropédica, State of Rio de Janeiro, Brazil. Nine stemflow collectors (in selected trees) and nine pluviometers were randomly disposed under each stand and three pluviometers were used to measure the incident rainfall during 5.5 months. Mangium conveyed 33.4% of the total rainfall for its stem. An estimative based on corrections for the average annual precipitation (1213 mm) indicated that the rainfall's contribution to the nutrient input (kg ha-1) was about 8.42; 0.95; 19.04; 6.74; 4.72 and 8.71 kg ha-1 of N-NH4+, P, K+, Ca+2, Mg+2 and Na+, respectively. Throughfall provided the largest contributions compared to the stemflow nutrient input. The largest inputs of N-NH4+ (15.03 kg ha-1) and K+ (179.43 kg ha-1) were observed under the guachapele crown. Large amounts of Na+ denote a high influence of the sea. Mangium was the most adapted species to water competitiveness. Comparatively to pure stand of eucalyptus, the mixed plantation intensifies the N, Ca and Mg leaching by the canopy, while the inputs of K and P were lower under these plantations.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Neste trabalho, avaliaram-se o acúmulo de sais no solo e a produtividade do feijão-de-corda, em função da fração de lixiviação (FL) e da salinidade da água de irrigação. Utilizou-se de delineamento em blocos ao acaso, com quatro tratamentos e cinco repetições. Foram estudados os seguintes tratamentos: 1 - água do poço com condutividade elétrica (CEa) de 0,8 dS m-1 (sem FL); 2 - água salina com CEa de 5,0 dS m-1 sem FL; 3 - água salina com CEa de 5,0 dS m-1 com FL de 0,14; 4 - água salina com CEa de 5,0 dS m-1 com FL de 0,28. Foram avaliadas as seguintes variáveis: acúmulo de sais no solo, crescimento vegetativo, produtividade, trocas gasosas e teores de Na+, Ca+2, K+ e Cl- nas folhas. A aplicação de água salina provocou acúmulo de sais no solo, porém esses efeitos foram parcialmente revertidos pelo aumento da FL; a salinidade reduziu a produtividade de grãos, porém não afetou sua qualidade; a redução na produtividade ocasionada pela salinidade deveu-se, em parte, à redução na assimilação líquida de carbono durante as fases de floração e frutificação, associada aos efeitos osmóticos e ao acúmulo de Na+ e Cl- nas folhas; as frações de lixiviação não tiveram muita influência na superação dos danos provocados pela salinidade sobre o desenvolvimento das plantas.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Suunnitelmassa on kuvattu Uudenmaan ELY-keskuksen toiminta-alueen liikenneturvallisuustyÃn ja liikenneonnettomuuksien nykytilanne. MyÃs liikenneturvallisuuden toimintaympäristÃä ja sen muutostekijÃitä on kuvattu tiiviisti. Valtakunnallisten tavoitteiden ja nykytilan analyysien pohjalta asetettiin liikenneturvallisuustyÃn tavoitteet ja onnettomuuksien vähenemätavoite vuoteen 2020. Tavoitteiden saavuttamiseksi laadittiin monipuolinen toimenpideohjelma ja muodostettiin mittarit tavoitteiden toteutumisen seuraamiseksi. Vuonna 2012 alueen kunnista noin puolessa liikenneturvallisuustyÃtä koordinoi poikkihallinnollinen tyÃryhmä. Kunnissa tehokasta liikenneturvallisuustyÃtä rajoittavat eniten ajan ja rahoituksen puute, osittain myÃs arvostuksen puute. Seudullista liikenneturvallisuusyhteistyÃtä pidetään myÃs tarpeellisena. Liikennekuolemien määrä on puolittunut ELY-keskuksen alueella kymmenessä vuodessa. HenkilÃvahinko-onnettomuudet ovat vähentyneet valta- ja kantateillä, mutta lisääntyneet yhdysteillä. Nuorten onnettomuudet ovat kuitenkin lisääntyneet, ja neljännes kaikista henkilÃvahinko-onnettomuuksista tapahtuu 15â22-vuotiaille kuljettajille. Mopo-onnettomuuksissa kuolleiden ja loukkaantuneiden määrä on viimeisen vuosikymmenen aikana moninkertaistunut. Kuolonkolareista 30 prosentissa taustalla on sairaskohtaus, tajunnan menetys tai itsemurha. Kuolemaan johtaneet onnettomuudet maanteillä ovat useimmiten yksittäis- ja kohtaamisonnettomuuksia. Vuonna 2010 ELY-keskuksen alueen liikenneonnettomuuksissa menehtyi yhteensä 51 henkilÃä ja loukkaantui noin 2 430 henkilÃä. Tavoitteena on, että vuoteen 2020 mennessä liikennekuolemien määrä saadaan puolitettua ja loukkaantumiset saadaan vähenemään neljänneksellä. Toimenpideohjelma keskittyy Uudenmaan ELY-keskuksen vastuulla oleviin toimiin. Liikennekäyttäytymisen kehittämisen painopiste on kuntien KVT-tyÃn tukemisessa. LiikenneympäristÃn turvallisuuden parantamisessa korostuvat taajamien turvallisuus, ajonopeuksien hillintä sekä pienet ja kustannustehokkaat turvallisuustoimet. ELY-keskuksen liikenneturvallisuustyÃhÃn liittyvät toimenpide-ehdotukset sisältävät toimintatapojen, suunnittelujärjestelmän, tiedottamisen ja yhteistyÃn kehittämistä. Tärkeimmät toimenpiteet on nostettu kärkitehtäviksi. MyÃs ELY-keskuksen toiminta-alueen liikenneturvallisuustyÃn toimintamalli on kuvattu.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Maantie 170 (Uusi Porvoontie) toimii seudullisena yhteytenä ja valtatien 7 (E18 moottoritien) rinnakkaistienä Helsingistä SÃderkullan kautta Porvooseen ja paikallisena yhteytenä Hangelbyn ja Boxin välillä. Selvitysalueen länsiosassa maantien 170 ja maantien 1533 liittymästä alkaa nykyinen kevyen liikenteen väylä, joka kulkee maantien 170 rinnalla länteen SÃderkullan taajamaan. Maantien 1534 rinnalla kulkee kevyen liikenteen väylä, joka ulottuu selvitysalueen itäosassa maantien 170 ja maantien 1534 liittymään. Toimenpideselvityksessä esitetyt ratkaisut ovat yleispiirteisiä ja kuvaavat maastokäytävää, johon toimenpiteet voidaan toteuttaa. Maantien 170 yhteyteen tien pohjoispuolelle ehdotetaan rakennettavaksi kevyen liikenteen väylä maantien 1533 liittymästä maantien 1534 ja maantien 11694 liittymään. Kevyen liikenteen väylän pituudeksi tulee noin 2,5 kilometriä. Suunnitelman mukaisiksi rakentamiskustannuksiksi on arvioitu noin 0,93 Mâ¬. Rakentamalla uusi kevyen liikenteen väylä, parannetaan jalankulkijoiden ja pyÃräilijÃiden liikkumisolosuhteita sekä turvallisuutta alueella. MyÃs edellytykset koululaisten itsenäiselle liikkumiselle alueella parantuvat. Tämä lisää kevyen liikenteen matkoja alueella. Kevyen liikenteen väylän rakentaminen täydentää alueen nykyistä kevyen liikenteen verkkoa ja poistaa verkollisen yhteyden puutteen SÃderkullan taajaman ja Boxin kylän välillä. Uusi kevyen liikenteen väylä parantaa myÃs seudullisia yhteyksiä pääkaupunkiseudulta Porvoon suuntaan. Selvityksen ja siitä saatujen lausuntojen perusteella Uudenmaan ELY-keskus tekee hankkeesta jatkosuunnittelupäätÃksen. Hanke ei sisälly Uudenmaan ELY-keskuksen tienpidon ja liikenteen suunnitelmaan 2012â2015. Hankkeen toteuttamisajankohtaa voidaan arvioida vasta siinä vaiheessa, kun hanke päätetään toteuttaa ja se viedään tienpidon ja liikenteen suunnitelmaan. Ennen toteutusta hankkeesta laaditaan tiesuunnitelma ja asiakirjat rakentamista varten.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Leaves of Ficus microcarpa L. f., Quercus robur L., and Alchornea triplinervia (Spreng.) Muell. Arg., submerged in a stream of the Atlantic rainforest in the "Reserva Biológica do Alto da Serra de Paranapiacaba", State of São Paulo, Brazil, were collected monthly, from April to November 1990, in order to determine the number of fungal occurrences (zoosporic fungi and aquatic Hyphomycetes), and the content of total N (%), total P (%), K+ (%), Ca+2 (%), Mg+2 (%), S+3 (%), Fe+3 (ppm), Cu+3 (ppm), Mn+2 (ppm), Zn+2 (ppm), Bo (ppm), Na+2 (ppm) and Al+3 (ppm). According to the tests of Kruskal-Wallis, Mann-Whitney and Wilcoxon, the means of the mineral content of the three types of leaves were significantly different, except for Mg+2 (%), Mn+2 (ppm), Zn+2 (ppm) and Na+2 (ppm). On comparing the mineral content with the number of fungal occurrence, an independence test showed a positive correlation between the presence of zoosporic fungi on the leaves of A. triplinervia and the total nitrogen, phosphorus and S+3 content, whereas the aquatic Hyphomycetes depended on the amount of Ca+2 available. Regarding leaves of F. microcarpa, the occurrence of zoosporic fungi was linked to the S+3 level, and the presence of aquatic Hyphomycetes, to the content of K+, Ca+2, S+3 and Bo. On Q. robur leaves, zoosporic fungi showed a positive correlation with the Ca+2 content, but a negative one with Fe+3 and Al+3 levels, while the occurrence of aquatic Hyphomycetes was influenced by the content of Ca+2, Mg+2, Fe+3, Al+3, Mn+2, Zn+2 and Na+2. The correlation between the occurrence number of aquatic Hyphomycetes and a high mineral content indicates that their nutritional requirements may be more complex than those of zoosporic fungi. Further studies are still required to understand the implications of this tendency on the diversity of aquatic native mycota.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

We examined some of the mechanisms by which the aspirin metabolite and the naturally occurring metabolite gentisic acid induced relaxation of the guinea pig trachea in vitro. In preparations with or without epithelium and contracted by histamine, gentisic acid caused concentration-dependent and reproducible relaxation, with mean EC50 values of 18 µM and Emax of 100% (N = 10) or 20 µM and Emax of 92% (N = 10), respectively. The relaxation caused by gentisic acid was of slow onset in comparison to that caused by norepinephrine, theophylline or vasoactive intestinal peptide (VIP). The relative rank order of potency was: salbutamol 7.9 > VIP 7.0 > gentisic acid 4.7 > theophylline 3.7. Gentisic acid-induced relaxation was markedly reduced (24 ± 7.0, 43 ± 3.9 and 78 ± 5.6%) in preparations with elevated potassium concentration in the medium (20, 40 or 80 mM, respectively). Tetraethylammonium (100 µM), a nonselective blocker of the potassium channels, partially inhibited the relaxation response to gentisic acid, while 4-AP (10 µM), a blocker of the voltage potassium channel, inhibited gentisic acid-induced relaxation by 41 ± 12%. Glibenclamide (1 or 3 µM), at a concentration which markedly inhibited the relaxation induced by the opener of ATP-sensitive K+ channels, levcromakalim, had no effect on the relaxation induced by gentisic acid. Charybdotoxin (0.1 or 0.3 µM), a selective blocker of the large-conductance Ca2+-activated K+ channels, caused rightward shifts (6- and 7-fold) of the gentisic acid concentration-relaxation curve. L-N G-nitroarginine (100 µM), a NO synthase inhibitor, had no effect on the relaxant effect of gentisic acid, and caused a slight displacement to the right in the relaxant effect of the gentisic acid curve at 300 µM, while methylene blue (10 or 30 µM) or ODQ (1 µM), the inhibitors of soluble guanylate cyclase, all failed to affect gentisic acid-induced relaxation. D-P-Cl-Phe6,Leu17[VIP] (0.1 µM), a VIP receptor antagonist, significantly inhibited (37 ± 7%) relaxation induced by gentisic acid, whereas CGRP (8-37) (0.1 µM), a CGRP antagonist, only slightly enhanced the action of gentisic acid. Taken together, these results provide functional evidence for the direct activation of voltage and large-conductance Ca+2-activated K+ channels, or indirect modulation of potassium channels induced by VIP receptors and accounts for the predominant relaxation response caused by gentisic acid in the guinea pig trachea.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The endothelins (ET-1, 2 and 3) constitute a family of 21 amino acid peptides with potent biological activities. ET-1 is one of the most potent endogenous vasoconstrictors so far identified and its increased concentration in plasma appears to be closely related to the pathogenesis of arterial hypertension as well as to obstructive sleep apnea (OSA). OSA patients exhibit repetitive episodes of apnea and hypopnea that result in hypoxia and consecutive arousals. These patients are chronically sleep deprived, which may aggravate the hypertensive features, since literature data show that sleep deprivation results in hypertension both in humans and in animals. Based on the reported relationship between ET-1, hypertension and sleep deprivation consequences, the purpose of the present study was to determine plasma ET concentrations in paradoxical sleep-deprived animals. Male Wistar rats, 3 to 4 months old (N = 10 per group), were deprived of sleep for 24 and 96 h by the platform technique and plasma ET-1/2 was measured by radioimmunoassay. Analysis of plasma revealed that 96 h of sleep deprivation induced a significant increase in ET-1/2 release (6.58 fmol/ml) compared to control (5.07 fmol/ml). These data show that sleep deprivation altered plasma ET-1/2 concentrations, suggesting that such an increase may participate in the genesis of arterial hypertension and cardiorespiratory changes observed after sleep deprivation.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Vernonia scorpioides has been widely used in Brazil to treat skin problems and chronic wounds, such as ulcers of the lower limbs and diabetic lesions. In the present study, we investigated the effect of a dichloromethane (DCM) fraction of V. scorpioides leaf extract on Ehrlich ascitic and solid tumor-bearing mice. The animals were treated once a day with the DCM fraction at a concentration of 5 mg/kg, administered ip during and after the development of the tumor. The lifespan, weight, number and type of leukocytes, number of tumor cells, volume of solid and ascitic tumors were measured. The development of the tumor with pre-treated tumor cells in vitro with the DCM fraction (5 mg/kg) was analyzed and the animals were sacrificed after 7 days. The DCM fraction (5 mg/kg) totally inhibited tumor development when in direct contact with tumor cells, and also ascitic tumor development with in vitro treatment or when administered ip, in loco (after 7 days). Animals treated with the DCM fraction increased their lifespan ca. 2 weeks and maintained their body weight for 30 days. When applied immediately after the inoculation of the tumor cells in vivo, it totally abolished tumor development, with tumor development only decreasing when treatment was started 3 days after the tumor challenge. These data suggest an antineoplastic activity of the fraction. Oral or ip administration of DCM fraction (5 mg/kg) for 7 days did not reduce the solid tumor volume. The cytotoxic activity described here differs from the conventional immune suppressing profile of standard chemotherapy because it increases neutrophil influx to the peritoneal cavity. These results show that, besides exhibiting a tumoricidal activity, the DCM fraction also exhibits inflammatory activity.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Landsväg 741 är en regionväg som gÃ¥r genom byarna Sisbacka och Lillby. Vägen startar i Lappajärvi och gÃ¥r via Kortesjärvi till Bennäs och Jakobstad. Vägens trafikmängd (GDT) är i byarna ca 1500 fordon/dygn. InvÃ¥narna upplever att stÃrsta problemet är bristen pÃ¥ gÃ¥ng- och cykelvägar. I byarna finns bebyggelse och nÃ¥gra nya hus byggs Ã¥rligen i jämn takt. Vägen är smal och delvis krokig, sÃ¥ledes är fotgängarens och cyklistens ställning inte trygg. Dessutom finns anslutningar med dÃ¥lig sikt och pÃ¥ avsnittet mellan byarna saknas belysning pÃ¥ en ca 2 km lÃ¥ng sträcka. Vägnätsplanens mÃ¥lsättning är att reda ut vägavsnittets trafikmässiga fÃrbättringsbehov och ge fÃrslag till Ã¥tgärdsprogram. Utredningen är även en trafikmässig bakgrundsutredning fÃr omrÃ¥dets planläggningsbehov. FÃrbättringsÃ¥tgärderna har delats in i tre olika prioritetsklasser. I det fÃrsta skedet sänks kÃrhastigheten i bÃ¥da byarna och smÃ¥ säkerhetsÃ¥tgärder gÃrs fÃr att understÃda hastighetssänkningen. Ãven de farligaste anslutningarna fÃrbättras och gÃ¥ng- och cykelleden i Lillby fÃrlängs med ca 400 meter. I det andra skedet anläggs en gÃ¥ng- och cykelled i byn Sisbacka och tätortsportar anläggs pÃ¥ bÃ¥da sidorna av tätortsgränserna. I Lillby fÃrlängs gÃ¥ng- och cykelleden sÃderut 1,1 km och den befintliga leden i centrum repareras. I det tredje skedet fÃrnyas gÃ¥ngbron som korsar Ã¥n i Lillby och en ny gÃ¥ng- och cykelled anläggs till det planerade bostadsomrÃ¥det i Yttre Härmälä. Vägavsnittet mellan byarna fÃrses med vägbelysning. Genom Ã¥tgärderna fÃrbättras speciellt säkerheten fÃr den lätta trafiken bÃ¥de i vägens riktning men ocksÃ¥ i den korsande riktningen. En brist kvarstÃ¥r dock i Ã¥tgärdsprogrammet. I programmet ingÃ¥r inte byggande av en gÃ¥ng- och cykelled längs hela vägsträckan mellan byarna. Ãtgärderna har ingen stor inverkan pÃ¥ naturmiljÃn eller kulturmiljÃn. Purmo kyrka i Sisbacka är ett objekt med värde, i vars närhet gÃ¥ng- och cykellederna placeras. PÃ¥ basen av planeutkastet bevaras kyrkans murar och hanteringen av omrÃ¥det mellan muren och leden lÃses i den noggrannare planeringen. FÃrverkligande av gÃ¥ng- och cykellederna i Sisbacka fÃrutsätter ändringar i detaljplanen. Maantie 741 on seututie, joka kulkee Sisbackan ja Lillbyn kylien läpi. Tie lähtee Lappajärvelä ja Tulee Kortesjärven kautta Pännäisiin ja Pietarsaareen. Tien liikennemäärä (KVL) on kylien kohdalla n. 1500 ajon/vrk. Isoimpana ongelmana asukkaat kokevat kevyen liikenteen väylän puuttumisen. Kylissä on asutusta ja uusia taloja rakennetaan tasaisesti muutaman talon vuosivauhtia. Tie on kapea ja osittain mutkainen, joten jalankulkijan ja pyÃräilijän asema ei ole turvallinen. On myÃs liittymiä, joissa on huono näkemä ja kylien väliltä puuttuu n. 2 km valaistusta. Tieverkkosuunnitelman tavoitteena on selvittää tiekäytävän liikenteelliset parantamistarpeet ja tehdä esitys parantamisen toimenpideohjelmaksi. Selvitys on myÃs liikenteellinen taustaselvitys alueen kaavoitustarpeita varten. Parantamistoimenpiteet on jaettu kolmeen kiireellisyysluokkaan. Ensimmäisessä vaiheessa alennetaan molempien kylien ajonopeuksia ja tehdään nopeuden alentamista tukevia pieniä turvallisuustoimenpiteitä. MyÃs vaarallisimpia liittymiä parannetaan ja Lillbyn kevyen liikenteen väylää jatketaan etelään vajaat. 400 m. Toisessa vaiheessa rakennetaan Sisbackan kylään kevyen liikenteen väylä ja taajamaportit taajaman molemmille reunoille. Lilbyssä jatketaan kevyen liienteen väylää etelään 1,1 km lisää ja kunnostetaan nykyistä väylää keskustan kohdalla. Kolmannessa vaiheessa uusitaan Lillbyssä joen ylittävä kevyen liikenteen silta ja rakentaan kevyen liikenteen väylä suunnitellulle uudelle asuinalueelle Yttre Härmälään. Kylien välinen tieosuus valaistaan. Toimenpiteillä parannetaan erityisesti kevyen liikenteen liikenneturvallisuutta sekä tien suunnassa että tien poikki kuljettaessa. Puutteeksi jää edelleen se, että toimenpideohjelmaan ei mahtunut kevyen liikenteen väylää koko kylien väliselle osuudelle. Toimenpiteillä ei ole suuria vaikutuksia luonnonympäristÃn tai kulttuuriympäristÃÃn. Purmon kirkko Sisbackassa on arvokohde, jonka läheisyyteen kevyen liikenteen väylät sijoittuvat. Suunnitelmaluonnoksen perusteella kirkon muurit säilyvät ja muurin ja väylän välisen alueen käsittely ratkaistaan tarkemmassa suunnittelussa. Kevyen liikenteen väylien toteuttaminen Sisbackassa edellyttää asemakaavan muuttamista.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

O objetivo do presente trabalho foi de caracterizar as enzimas amilolíticas de mandioquinha-salsa (Arracacia xanthorrhiza Bancroft.). Foram realizados ensaios mediante a determinação da atividade enzimática, variando-se as condições do meio, tais como temperatura, pH e concentração de cátions. Em gel de eletroforese foram detectadas três bandas protéicas com intensa atividade hidrolítica. As enzimas apresentaram pH ótimo de atividade em torno de 6,0 e mostraram-se mais sensíveis a valores de pH alcalino quando pré-incubadas a 50oC. A temperatura ótima de ativação enzimática foi de 50oC, enquanto aos 70oC, a atividade amilásica foi reduzida em 80%. Em temperaturas altas temperaturas (60 e 70oC), a inativação enzimática ocorreu após 60 e 25min de incubação, respectivamente. Ensaios de estabilidade térmica mostraram que as amilases mantiveram alta atividade após 25h mediante a incubação a 20 e 30oC. Os valores de Km, Vmax e energia de ativação foram de 0,41mg/mL, 1,11mg/mL/min e 7,53kcal/mol, respectivamente. Constatou-se que a presença de Ca+2 ou Mg+2 provoca aumento na atividade amilásica, enquanto íons de Cu+2 causam uma diminuição. Apesar da discreta atividade amilásica apresentada, as enzimas demonstraram ter alta resistência e estabilidade térmicas.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Solvent extraction of calcium and magnesium impurities from a lithium-rich brine (Ca ~ 2,000 ppm, Mg ~ 50 ppm, Li ~ 30,000 ppm) was investigated using a continuous counter-current solvent extraction mixer-settler set-up. The literature review includes a general review about resources, demands and production methods of Li followed by basics of solvent extraction. Experimental section includes batch experiments for investigation of pH isotherms of three extractants; D2EHPA, Versatic 10 and LIX 984 with concentrations of 0.52, 0.53 and 0.50 M in kerosene respectively. Based on pH isotherms LIX 984 showed no affinity for solvent extraction of Mg and Ca at pH ⤠8 while D2EHPA and Versatic 10 were effective in extraction of Ca and Mg. Based on constructed pH isotherms, loading isotherms of D2EHPA (at pH 3.5 and 3.9) and Versatic 10 (at pH 7 and 8) were further investigated. Furthermore based on McCabe-Thiele method, two extraction stages and one stripping stage (using HCl acid with concentration of 2 M for Versatic 10 and 3 M for D2EHPA) was practiced in continuous runs. Merits of Versatic 10 in comparison to D2EHPA are higher selectivity for Ca and Mg, faster phase disengagement, no detrimental change in viscosity due to shear amount of metal extraction and lower acidity in stripping. On the other hand D2EHPA has less aqueous solubility and is capable of removing Mg and Ca simultaneously even at higher Ca loading (A/O in continuous runs > 1). In general, shorter residence time (~ 2 min), lower temperature (~23 °C), lower pH values (6.5-7.0 for Versatic 10 and 3.5-3.7 for D2EHPA) and a moderately low A/O value (< 1:1) would cause removal of 100% of Ca and nearly 100% of Mg while keeping Li loss less than 4%, much lower than the conventional precipitation in which 20% of Li is lost.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

INTRODUCTION: Mesangial cells (MC) may be involved in the glomerular alterations induced by ischemia/reperfusion injury. OBJECTIVE: To evaluate the response of immortalized MC (IMC) to 30 minutes of hypoxia followed by reoxygenation periods of 30 minutes (H/R30) or 24 hours (H/R24). METHODS: The intracellular calcium concentration (&#91;Ca+2&#93;i) was measured before (baseline) and after adding angiotensin II (AII, 10-5 M) in the presence and absence of glybenclamide (K ATP channel blocker). We estimated the level of intracellular ATP, nitric oxide (NO) and PGE2. RESULTS: ATP concentration decreased after hypoxia and increased after reoxygenation. Hypoxia and H/R induced increases in basal &#91;Ca+2&#93;i. AII induced increases in &#91;Ca+2&#93;i in normoxia (97 ± 9%), hypoxia (72 ± 10%) or HR30 (85 ± 17%) groups, but there was a decrease in the response to AII in group H/R24 since the elevation in &#91;Ca+2&#93;i was significantly lower than in control (61 ± 10%, p < 0.05). Glybenclamide did not modify this response. It was observed a significant increase in NO generation after 24 hours of reoxygenation, but no difference in PGE2 production was observed. Data suggest that H/R injury is characterized by increased basal &#91;Ca+2&#93;i and by an impairment in the response of cells to AII. Results suggest that the relative insensibility to AII may be at least in part mediated by NO but not by prostaglandins or vasodilator K ATP channels. CONCLUSION: H/R caused dysfunction in IMC characterized by increases in basal &#91;Ca+2&#93;i during hypoxia and reduction in the functional response to AII during reoxygenation.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The Pater metavolcanic suite (PVS) was extruded as part O'f the basal Pater Formation of the Huronian Supergroup ca. 2.4 Ga. They Ars classified as wi thin-plate tholeiites associated with an immature ri-fting episode, and are inter layered with associated vol cani clastic and metasedimentary units. Post-solidif ication alteration caused redistribution o-f the alkalies, Sr, Rb, Ba, Cu, and SiO^. Ce, Y, Zr, CFezOs (as total Fe), Al^Os, TiOa, and, PaOa are considered to have remained essentially immobile in least altered samples. Petrogenetic modelling indicates the PVS was derived from the partial melting of two geochemical ly similar sources in the sub-continental lithosphere. Fractionation was characterized by an oli vine-plagioclase assemblage and a sub-volcanic plagioclase-clinopyroxene assemblage. A comparative study indicates that enrichment of the postulated Huronian source cannot be reconciled by Archean contamination. Enrichment is thought to have been caused by hydrous veined metasomatic heterogeneities in the sub-continental lithosphere, generated by an Archean subduct ion event before 2.68 Ga.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Newspaper reporting on contemporary events of the wars in North America and Europe including the Battle of Queenston Heights and the death of Isaac Brock. News items include: Page 1: Sheaffe announcement regulating the sale of alcohol in Niagara; Myers announcement asking citizens for the return of American muskets recovered from the battle at Queenston; local notices on business claims and education; want ads for wood, straw, flour and pork for military use; announcement by the Prince Regent in Council putting an embargo on American ships. Page 2: release of American prisoners captured at Queenston; results of a battle by Riga, Latvia the French army under MacDonald against Russia; address of Emperor Alexander I of Russia to troops on declaring war on France; news of the British Navy; mediation between Spain and South American colonies; the security of Canadian properties in wartime; American ships leaving Britain with licenses. Page 3: American ships leaving Britain with licenses; Russian General Platoffâs (Platov) victory over Polish Uhlans; Battle of Salamanca with Lord Wellington. Page 4: report on the Battle of Queenston Heights and the death of Isaac Brock.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

An original Niagara area newspaper containing an account of the Battle of Queenston Heights and the death and burial of Sir Isaac Brock. The newspaper is dated October 24, 1812, eleven days after the death of General Brock. Topics of interest include: Page 1: Sheaffe announcement regulating the sale of alcohol in Niagara; Myers announcement asking citizens for the return of American muskets recovered from the battle at Queenston; local notices on business claims and education; want ads for wood, straw, flour and pork for military use; announcement by the Prince Regent in Council putting an embargo on American ships. Page 2: release of American prisoners captured at Queenston; news of the British Navy; the security of Canadian properties in wartime; American ships leaving Britain with licenses. Page 3: American ships leaving Britain with licenses Page 4: report on the Battle of Queenston Heights and the death of Isaac Brock.