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151.
152.
Campos E Cordeiro R Santos AC Matos C Gil MH 《Colloids and surfaces. B, Biointerfaces》2011,88(1):477-482
Bi-soft segmented poly(ester urethane urea) microparticles were prepared and characterized aiming a biomedical application. Two different formulations were developed, using poly(propylene glycol), tolylene 2,4-diisocyanate terminated pre-polymer (TDI) and poly(propylene oxide)-based tri-isocyanated terminated pre-polymer (TI). A second soft segment was included due to poly(?-caprolactone) diol (PCL). Infrared spectroscopy, used to study the polymeric structure, namely its H-bonding properties, revealed a slightly higher degree of phase separation in TDI-microparticles. TI-microparticles presented slower rate of hydrolytic degradation, and, accordingly, fairly low toxic effect against macrophages. These new formulations are good candidates as non-biodegradable biomedical systems. 相似文献
153.
A sensitive method using LC/ESI-MS(n) has been developed on a quadrupole linear ion trap mass analyser for the detection of nine β(2) agonists (cimaterol, clenbuterol, fenoterol, formoterol, mabuterol, terbutaline, ractopamine, salbutamol and salmeterol) in horse urine. The method consists of solid-phase extraction on CSDAU cartridges before analysis by LC/ESI-MS(n) . The efficiency of extraction combined with the sensitivity and the selectivity of MS(n) allowed the detection of these compounds at pg/mL levels. Administration studies of fenoterol and formoterol are reported and show their possible detection after inhalation. The method is applicable for screening and confirmatory analysis. 相似文献
154.
We consider a second-order matrix ordinary regular differential nonselfadjoint operator with a damping term and selfadjoint
boundary conditions. An estimate for the resolvent and bounds for the spectrum are established. An operator is said to be
stable if its spectrum lies in the right half-plane. By the obtained bounds, stability and instability conditions are established. 相似文献
155.
We study the problem of when the collection of the recession cones of a polyhedral complex also forms a complex. We exhibit
an example showing that this is no always the case. We also show that if the support of the given polyhedral complex satisfies
a Minkowski–Weyl-type condition, then the answer is positive. As a consequence, we obtain a classification theorem for proper
toric schemes over a discrete valuation ring in terms of complete strongly convex rational polyhedral complexes. 相似文献
156.
157.
Salinas Y Climent E Martínez-Máñez R Sancenón F Marcos MD Soto J Costero AM Gil S Parra M de Diego AP 《Chemical communications (Cambridge, England)》2011,47(43):11885-11887
Silica nanoparticles containing polyamines and thiol groups have been used as probes for the selective detection of Tetryl. 相似文献
158.
Luciano N. Batista Rosane A. S. San Gil Luciana B. R. Lopes Vera L. P. Soares 《Journal of Thermal Analysis and Calorimetry》2011,106(3):697-702
This work describes thermal analysis evaluation of a glycerol derived compound (fatty acid esters of (2,2-dimethyl-1,3-dioxolan-4-yl)
methanol) developed to work as a biofuel. Mixtures of these ketal–glyceryl esters with fatty acid methyl esters typical of
soybean biodiesel were prepared and evaluated in relation to biodiesel critical thermal properties such as temperature of
crystallization, thermal stability and volatilization measured by differential scanning calorimetry and thermogravimetric
analysis. The volatility of the products containing fatty acid methyl esters and (2,2-dimethyl-1,3-dioxolan-4-yl) methyl esters
could be predicted by thermogravimetric analyses conducted in nitrogen that avoided time consuming distillation and greatly
reduced material expenditure. 相似文献
159.
160.
L. M. Gandía M. A. Vicente P. Oelker P. Grange A. Gil 《Reaction Kinetics and Catalysis Letters》1998,64(1):145-151
A Na-montmorillonite was intercalated with manganese- and samarium-manganese-aluminium solutions. The pillared montmorillonites
were characterized by X-ray diffraction and nitrogen adsorption. The presence of manganese and samarium-manganese citrates
in the intercalation process modify the distance between the clay sheets and the microporous structure of the pillared montmorillonites. 相似文献