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1.
J Environ Manage ; 231: 232-240, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30342336

RESUMO

The development of technologies for unconventional hydrocarbon exploration requires designing procedures to manage drilling waste that are consistent with the waste management hierarchy. In view of this, the possibility to apply shale drill cuttings as a prospective additive (replacing bentonite) to fly ash used for the production of lightweight aggregates (LWAs) was investigated. Moreover, a facile, waste-free method of LWAs production with using shales was proposed. Cuttings were characterized in terms of their mineralogical and elemental composition (XRD and XRF) as well as thermophysical behavior (TG-DTA and fusibility test). The sintered product, in turn, was assessed taking into account its structure, physicochemical and mechanical properties. It was found that the composition of the shale drill cuttings meets the conditions required for the bloating (as expressed by the SiO2/ΣFlux and Al2O3/SiO2 ratios) and binding processes (Al2O3 content), essential for the aggregates production. In comparison to bentonite, shales provided an additional source of kaolinite, which thermal transformation to mullite is crucial for the formation of mechanically durable structure of the aggregate. Moreover, the bulk density of the sintered product was found to be less than 1200 kg/m3, and the dry particle density below 2000 kg/m3, confirming that the obtained porous material belong to lightweight aggregates with accordance to European standard (UNE-EN-13055-1). The porosity of LWA was found to be higher (even up to 50%), thus the apparent density lower, compared with the reference product containing bentonite. These properties were accompanied by the relatively high crushing resistance which was up to 4.4 N/mm2. Hereby, usefulness of shale drill cuttings for LWAs production was confirmed.


Assuntos
Dióxido de Silício , Gerenciamento de Resíduos , Bentonita , Cinza de Carvão , Estudos Prospectivos
2.
Dalton Trans ; 49(3): 697-710, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31848544

RESUMO

Blue crystals of five heteroleptic cobalt(ii) silanethiolates 1-5 have been obtained by the reaction of [Co{SSi(tBuO)3}2(NH3)]2 with aminopyridines and aminomethylpyridines at an appropriate molar ratio and their structural, spectral, thermal and magnetic properties have been established and described. All complexes 1-5 contain Co(ii) ions in a tetrahedral CoN2S2 environment formed by (tBuO)3SiS- residues and pyridines and present variable structures. Complexes 1-3 are mononuclear [Co{SSi(tBuO)3}2(L1)2] (L1 = 2-aminopyridine 2AP, 3-aminopyridine 3AP, and 4-aminopyridine 4AP). The application of 3AMP and 4AMP (3-aminomethylpyridine and 4-aminomethylpyridine) allows either dinuclear complex 4 [Co{SSi(tBuO)3}2(µ-3AMP)]2 or 1D coordination polymer 5 with the formula of [Co{SSi(tBuO)3}2(µ-4AMP)]n to be obtained. The molecular structures of 1-5 were determined by single-crystal X-ray and powder diffraction, UV-vis and FTIR spectrocopy for solid samples and their thermal properties were characterized by TG-DSC and TG-FTIR methods. The dc and ac magnetic and EPR studies of polycrystalline samples have been performed. For all complexes, the obtained data show a behavior typical of paramagnetic high-spin Co(ii) ions in a tetrahedral geometry, with a considerable contribution of the ZFS effect in a low temperature range. All complexes were also probed for SIM behavior. The modeling of the magnetic and EPR data was done for samples 1, 3, 4 and 5 to estimate ZFS parameters. The obtained results imply a negative value of the axial parameter D in complex 4 and positive D values for the rest of the compounds. A comparative magneto-structural analysis of complexes 4 and 5 points to the high sensitivity of the single-ion magnetic anisotropy of tetrahedral Co(ii) complexes to subtle changes in the first and second coordination spheres of Co(ii) ions.

3.
Chemistry ; 15(35): 8880-5, 2009 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-19630011

RESUMO

Some ionic liquids (ILs) are structurally analogous to surfactants, especially those that consist of a combination of organic and inorganic ions. The critical micelle concentration (CMC) is a basic parameter of surface chemistry and colloid science. A significant amount of research has already been carried out to determine the CMCs of ILs. However, because of the many varied cation/anion combinations, it is a daunting task to measure the CMCs of all possible ILs. Herein we suggest a general rule for predicting the CMCs of ionic surfactants in water based on data from COSMO-RS calculations. In accordance with the Stauff-Klevens rule, the molecular volume (V(m)) is sufficient to describe similar homologous series of cationic surfactants such as imidazolium- and ammonium-based ionic liquids with varying side-chain lengths. However, to also include anionic surfactants like Na[C(n)SO(4)] in a more general correlation, V(m) has to be exchanged by the cubed molecular radius (r3(m)) and the molecular surface has to be used as an additional descriptor. Furthermore, to describe double amphiphilic compounds like [C(4)MIm][C(8)SO(4)], the enthalpies of mixtures calculated by COSMO-RS have to be taken into account. The resulting equation had allowed us to predict the CMCs of all of the 36 tested surfactants with an error similar to or smaller than the usual experimental errors (18 different cations, 10 different anions: root mean squared error (rmse)=0.191 logarithmic units; R(2)=0.994). We discuss the factors governing micelle formation on the basis of our calculations and show that the structure of our equation can be related to Gibbs' theory of crystallization.

4.
J Physiol Pharmacol ; 69(4)2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30415240

RESUMO

Pharmacotherapy with agents that inhibit platelet function has proven to be effective in the treatment of acute coronary syndrome. Proper re-endothelization after angioplasty prevents adverse cardiovascular events. Therefore, in this in vitro study we examined how antiplatelet P2Y12 receptor blockers can affect endothelial cells' angiogenic properties. Endothelial cells were exposed to ticagrelor, prasugrel and clopidogrel in their highest concentrations obtained in serum after the treatment with loading and clinical doses. Further, the viability, apoptosis, and necrosis were tested and the following angiogenic properties such as proliferation, migration, invasiveness, tube formation, wound healing and the production of angiogenic mediators (bFGF, PDGF, MMP-2, Ang-2, TIMP-1). The results of this study showed that P2Y12 receptor blockers in the tested concentrations are safe for endothelial cells. They neither induced necrosis or apoptosis nor changed the endothelial cell viability, migration, invasiveness, tube formation, wound healing, the production of VEGF or its receptors. However, they reduced cell proliferation. It was shown that out of these three drugs, ticagrelor in its loading concentration had the most potent angiogenic property. It reduced cell proliferation and changed the production of angiogenic (bFGF, MMP-2) and angiostatic mediators (Ang-2). In conclusion, P2Y12 receptor blockers in the concentrations obtained in the serum during standard therapy reduced endothelial cell proliferation. Despite this slight antimitogenic effect, they did not change endothelial cell tube formation or wound healing. Out of the three tested drugs, ticagrelor had the most potent angiogenic effect in vitro, but not strong enough to disturb tube formation and wound healing.


Assuntos
Células Endoteliais/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Clopidogrel/farmacologia , Células Endoteliais/fisiologia , Humanos , Cloridrato de Prasugrel/farmacologia , Ticagrelor/farmacologia , Cicatrização/efeitos dos fármacos
5.
Amino Acids ; 33(4): 663-7, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17146591

RESUMO

The 1-(N-trifluoroacetylamino)alkylphosphonic acids (TFA-AA(P)) - sub-products in the synthesis of O,O-dialkyl 1-(N-trifluoroacetylamino)alkylphosphonates and O,O-diethyl 1-aminoalkylphosphonates, were synthesized in two-stage transformations of 1-aminoalkylphosphonic acids including: trifluoroacetylation of 1-aminoalkylphosphonic acids (AA(P)) using a trifluoroacetic anhydride/trifluoroacetic acid reagent (AA(P) + TFAA/TFA-->2) and subsequent hydrolysis of the intermediary compounds 2 into desired TFA-AA(P) (2-->TFA-AA(P)). These intermediates 2 presented mixtures of the type of mixed anhydrides of TFAA and 1-(N-trifluoroacetylamino)alkylphosphonic, pyrophosphonic and polyphosphonic acids, which underwent rapid and quantitative conversion to corresponding TFA-AA(P) during treatment with an excess of water. The title acids were isolated by direct evaporation of the corresponding post-reaction mixtures, and their physicochemical proprieties, including deacylation abilities, were determined. TFA-AA(P) compounds can be re-converted into the starting amino acids AA(P) under respectively mild conditions (AA(P)-->TFA-AA(P)-->AA(P)).


Assuntos
Organofosfonatos/química , Organofosfonatos/síntese química , Acetilação , Acilação , Espectroscopia de Ressonância Magnética , Estrutura Molecular
6.
J Physiol Pharmacol ; 68(4): 597-608, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29151077

RESUMO

Endothelial cell dysfunction in obesity can be reduced by calorie restriction (CR), however it is unclear whether this benefit requires a concomitant weight loss or is it simply related to the reduced calorie intake per se. In our study serum was drawn from 41 obese women who were undergoing an 8-week dietary intervention with 15 - 30% energy deficit, and from 48 age- and sex-matched controls of normal weight. Serum was analysed for biomarkers of endothelial cell function, oxidative stress and inflammation. Compared with non-obese individuals, the obese patients had lower serum levels of nitric oxide (NO), adiponectin, and decreased serum antioxidant status. They also had significantly higher levels of adhesive molecules, thrombomodulin (TM), von Wilebrand factor (vWF), asymmetric dimethylarginine (ADMA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and leptin. To further characterize the effect of moderate CR, the patients were ranked into two comparable groups according to the extent of weight loss - below and above the median (-5.8 kg). A moderate dietary intervention did not correct adiponectin, antioxidant status, vWF, TM, and plasminogen activator inhibitor-1 (PAI-1) but ameliorated changes in other parameters. Only changes in NO and - to a lesser degree - in sE-selectin showed a clear relationship with the magnitude of weight reduction. By contrast, a beneficial reduction in TNF-α occurred equally in patients who lost more or less weight after caloric restriction. We concluded that moderate calorie restriction could still improve several parameters of endothelial cell function irrespective of whether it was accompanied by changes in body mass. However, a significant improvement in nitric oxide, a key mediator of endothelial well-being, requires a substantial reduction in body weight.


Assuntos
Biomarcadores/sangue , Células Endoteliais/metabolismo , Obesidade/sangue , Redução de Peso/fisiologia , Adiponectina/sangue , Adulto , Antioxidantes/metabolismo , Peso Corporal/fisiologia , Restrição Calórica/métodos , Células Endoteliais/fisiologia , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Feminino , Humanos , Inflamação/sangue , Inflamação/metabolismo , Inflamação/fisiopatologia , Leptina/sangue , Óxido Nítrico/sangue , Estresse Oxidativo/fisiologia
8.
Pain ; 80(1-2): 121-5, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10204724

RESUMO

Opioids used topically may exercise several useful clinical effects. Opioids may cause immediate local analgesia and also may work indirectly through decreasing the inflammation process. In this article we describe six patients treated with topical opioids because of cutaneous pain due to tumor infiltration. skin ulcers of malignant and non-malignant origin, severe oral mucositis, pain due to knee arthrosis and severe tenesmoid pain. In all but one case, topical morphine provided rapid relief which lasted usually for 7-8 h. The side effects of topical opioids were none or minimal. Possible mechanisms of topical analgesia are discussed.


Assuntos
Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/uso terapêutico , Dor Intratável/tratamento farmacológico , Cuidados Paliativos , Administração Tópica , Idoso , Idoso de 80 Anos ou mais , Feminino , Géis , Humanos , Masculino , Pessoa de Meia-Idade , Morfina/administração & dosagem , Morfina/uso terapêutico , Neoplasias/complicações , Dor Intratável/etiologia
9.
J Wound Care ; 11(3): 107-10, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11933727

RESUMO

OBJECTIVES: This study aimed to identify the quantitative and qualitative bacteriological status of pressure ulcers in patients with advanced cancer, and the effects on the healing process. METHOD: We recruited 34 patients with advanced cancer who had 38 superficial grade II and III pressure ulcers. Patients were randomly allocated to treatment with Lyofoam/polyurethane foam dressing (Seton) or Aquagel/hydrogel dressing (Wytw.Opatrunków). Efficacy, treatment times and healing rates were noted. Qualitative studies were undertaken on 38 pressure ulcers and quantitative bacteriological studies on 19 ulcers. RESULTS: There was no statistical difference between the two treatment groups in efficacy, healing rates and treatment times. Bacteriological assessment identified 92 species. CONCLUSION: The bacteria did not cause any clinical signs of infection. Variations in the number and types of bacteria in individual wounds did not correlate to the grade of ulcer or the dressing used.


Assuntos
Infecções Bacterianas/terapia , Bactérias Gram-Negativas/patogenicidade , Bactérias Gram-Positivas/patogenicidade , Neoplasias/complicações , Úlcera por Pressão/microbiologia , Úlcera por Pressão/terapia , Cicatrização/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções Bacterianas/microbiologia , Bandagens , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/patologia , Cuidados Paliativos/métodos , Úlcera por Pressão/complicações , Probabilidade , Prognóstico , Estudos Prospectivos , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Doente Terminal
10.
J Basic Clin Physiol Pharmacol ; 11(2): 109-25, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11037766

RESUMO

The aim of this study was to investigate possible interactions between the analgesic activity of ketamine (an N-methyl-D-aspartate antagonist), midazolam (a benzodiazepine derivative) and morphine using the tail-flick test in rats. Animals were treated s.c. with ketamine (1.0-10.0 mg/kg), midazolam (0.3 mg/kg), or morphine (0.6 mg/kg) alone. or in combination The strongest analgesic effect of ketamine was observed after 3.0 mg/kg. In higher doses no enhancement of ketamine activity were found. After morphine and ketamine (3.0 mg/kg) or morphine, midazolam and ketamine co-administration. higher antinociceptive effects compared to ketamine activity were found. Rats administered midazolam and ketamine (3.0 mg/kg) showed a decrease of the effect of ketamine analgesia, and the antinociceptive effect of the three-component mixture was lower than after co-injection of morphine and ketamine. The interaction of these two compounds with ketamine (5.0 mg/kg) occurred in a different manner, because midazolam led to a strong enhancement of ketamine analgesia. After morphine and ketamine (5.0 mg/kg) administration, very weak increase of ketamine analgesia was observed. The results of this study allow better understanding of the alteration of the analgesic effects of low doses of ketamine under the influence of morphine and midazolam.


Assuntos
Analgésicos/farmacologia , Ansiolíticos/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hipnóticos e Sedativos/farmacologia , Ketamina/farmacologia , Midazolam/farmacologia , Morfina/farmacologia , Animais , Relação Dose-Resposta a Droga , Masculino , Atividade Motora/efeitos dos fármacos , Ratos , Ratos Wistar
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