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141.
Prenatally malnourished rats develop hypertension in adulthood, in part through increased α1-adrenoceptor-mediated outflow from the paraventricular nucleus (PVN) to the sympathetic system. We studied whether both α1-adrenoceptor-mediated noradrenergic excitatory pathways from the locus coeruleus (LC) to the PVN and their reciprocal excitatory CRFergic connections contribute to prenatal undernutrition-induced hypertension. For that purpose, we microinjected either α1-adrenoceptor or CRH receptor agonists and/or antagonists in the PVN or the LC, respectively. We also determined the α1-adrenoceptor density in whole hypothalamus and the expression levels of α1A-adrenoceptor mRNA in the PVN. The results showed that: (i) agonists microinjection increased systolic blood pressure and heart rate in normotensive eutrophic rats, but not in prenatally malnourished subjects; (ii) antagonists microinjection reduced hypertension and tachycardia in undernourished rats, but not in eutrophic controls; (iii) in undernourished animals, antagonist administration to one nuclei allowed the agonists recover full efficacy in the complementary nucleus, inducing hypertension and tachycardia; (iv) early undernutrition did not modify the number of α1-adrenoceptor binding sites in hypothalamus, but reduced the number of cells expressing α1A-adrenoceptor mRNA in the PVN. These results support the hypothesis that systolic pressure and heart rate are increased by tonic reciprocal paraventricular–coerulear excitatory interactions in prenatally undernourished young-adult rats.  相似文献   
142.
Dications of cycloparaphenyles ([n]CPPs) are known to exhibit in-plane global aromaticity, contained in a nanobelt structure. Recently synthesized ortho and meta isomers of [n]CPPs break the radial symmetry of π structure incorporating perpendicular oriented π orbitals. Herein we set to explore the aromaticity of neutral and dicationic ortho and meta isomers of [8]CPP by dissecting the induced magnetic field to contributions of the twofold radial/perpendicular π system using delocalized canonical molecular orbitals (CMO), and introducing the natural localized molecular orbitals (NLMO) analysis with DFT methods. The dications sustain a reduced global aromatic character of the radial π system under a perpendicular orientation of the external field which declines from ortho to meta isomer and reinforces local aromaticity of ortho ring while it destroys aromaticity of meta ring. Aromaticity variations are determined by symmetry governed rotational excitations of frontier π orbitals. The parallel orientation reveals a substantial reduction of local aromaticity verified with NICSπ analysis and electron delocalization indices.  相似文献   
143.
Metal–organic frameworks (MOFs) have become one of the versatile solid materials used for a wide range of applications, such as gas storage, gas separation, proton conductivity, sensors and catalysis. Among these fields, one of the more well-studied areas is the use of MOFs as heterogeneous catalysts for a broad range of organic reactions. In the present review, the employment of MOFs as solid catalysts for the Henry reaction is discussed, and the available literature data from the last decade are grouped. The review is organized with a brief introduction of the importance of Henry reactions and structural properties of MOFs that are suitable for catalysis. The second part of the review discusses the use of MOFs as solid catalysts for the Henry reaction involving metal nodes as active sites, while the third section provides data utilizing basic sites (primary amine, secondary amine, amides and urea-donating sites). While commenting on the catalytic results in these two sections, the advantage of MOFs over other solid catalysts is compared in terms of activity by providing turnover number (TON) values and the structural stability of MOFs during the course of the reaction. The final section provides our views on further directions in this field.  相似文献   
144.
Amazonian fruits are excellent sources of bioactive compounds and can be used in beverages to improve the nutritional and sensorial characteristics. The present study aimed to develop a blend of murici (Byrsonima Crassifolia (L.) Kunth) and taperebá (Spondias Mombin L.) through experimental design and investigating the nutritional and sensorial characteristics of fruits and beverages. The murici was highlighted as higher vitamin C content (58.88 mg · 100 g−1) compared to taperebá (25.93 mg · 100 g−1). The murici and taperebá are good sources of total phenolic compounds (taperebá 1304.15 ± 19.14 mgGAE · 100 g−1 and the murici of 307.52 ± 19.73 mg GAE · 100 g−1) and flavonoids (174.87 ± 1.76 μgQE/g and 129.46 ± 10.68 μgQE/g, murici and taperebá, respectively), when compared to other Brazilian fruits. The antioxidant capacity in different methods revealed that the taperebá had a higher average in the results, only in the ORAC method and did not present a significant difference (p > 0.05) in relation to the murici. The beverage development was performed using experimental design 23, showed through sensory analysis and surface response methodology that murici and high sugar content (between 12.5 and 14.2% of sugar) influenced in sensory acceptance. Our findings indicate that beverages with improved nutrition and a sensory acceptance can be prepared using taperebá and murici fruits.  相似文献   
145.
This study was performed to investigate the physical–chemical characteristics of carvedilol (CRV), complemented by compatibility studies with a great variety of pharmaceutical excipients. Thermogravimetry and differential scanning calorimetry, supported by diffuse reflectance infrared fourier transform spectroscopy (DRIFT), X-ray powder diffraction, and scanning electron microscopy (SEM) were selected as the solid-state techniques for the intended analyses. In addition, non-isothermal methods were employed to investigate kinetic data of CRV decomposition process under nitrogen and air atmospheres. CRV is characterized by an endothermic sharp event (T peak = 389.81 K and ΔH fusion of ?176.28 J g?1) and a thermal decomposition behavior in two stages, totalizing 98 % of mass loss. The CRV pattern diffraction presents prominent peaks at 2θ: 5.92°, 14.90°, 18.62°, 24.47°, and 26.30°, and the DRIFT spectrum showed the main characteristics bands for CRV chemical functional groups. The SEM photomicrographs demonstrate that CRV is characterized by irregular blocky shaped crystals. Zero order kinetics was determined by Ozawa method in both nitrogen and air atmospheres. The compatibility results showed no evidence of any incompatibility among CRV and all the excipients analyzed.  相似文献   
146.
147.
The first example of a self‐propelled tubular motor that releases an enzyme for the efficient biocatalytic degradation of chemical pollutants is demonstrated. How the motors are self‐propelled by the Marangoni effect, involving simultaneous release of SDS surfactant and the enzyme remediation agent (laccase) in the polluted sample, is illustrated. The movement induces fluid convection and leads to the rapid dispersion of laccase into the contaminated solution and to a dramatically accelerated biocatalytic decontamination process. The greatly improved degradation efficiency, compared to quiescent solutions containing excess levels of the free enzyme, is illustrated for the efficient biocatalytic degradation of phenolic and azo‐type pollutants. The high efficiency of the motor‐based decontamination approach makes it extremely attractive for a wide‐range of remediation processes in the environmental, defense and public health fields.  相似文献   
148.
149.
A gram‐scale catalytic enantioselective formal synthesis of morphine is described. The key steps of the synthesis involve an ortho–para oxidative phenolic coupling and a highly diastereoselective “desymmetrization” of the resulting cyclohexadienone that generates three of the four morphinan ring junction stereocenters in one step. The stereochemistry is controlled from a single carbinol center installed through catalytic enantioselective hydrogenation. These transformations enabled the preparation of large quantities of key intermediates and could support a practical and scalable synthesis of morphine and related derivatives.  相似文献   
150.
The development of technologies for cellulosic ethanol production by simultaneous saccharification and fermentation (SSF) depends on the use of microorganisms with high fermentative rates and thermotolerance. In this study, the ability of five Kluyveromyces marxianus strains to produce ethanol from glucose at 45 °C was investigated. The highest fermentative parameters were observed with K. marxianus NRRL Y-6860, which was then further studied. An initial evaluation of the oxygen supply on ethanol production by the selected yeast and a comparison of SSF process from acid pretreated rice straw between K. marxianus NRRL Y-6860 and Saccharomyces cerevisiae at 30 and 45 °C were carried out. Under the lowest evaluated conditions of aeration and agitation, K. marxianus NRRL Y-6860 produced 21.5 g/L ethanol from 51.3 g/L glucose corresponding to YP/S of 0.44 g/g and QP of 3.63 g/L h. In the SSF experiments, K. marxianus NRRL Y-6860 was more efficient than S. cerevisiae at both evaluated temperatures (30 and 45 °C), attained at the highest temperature an ethanol yield of 0.24 g/g and productivity of 1.44 g/L h.  相似文献   
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