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11.
A simple, fast and accurate Fourier transform mid-infrared spectroscopy method was developed for simultaneously determining sugar and organic acid contents in apricot fruit slurries using the attenuated total reflectance. The potential of this method coupled with chemometric techniques based on partial least squares was assessed by comparison with currently used enzymatic determination of sucrose, glucose, fructose, malic acid and citric acid. Fruits of eight contrasted cultivars harvested at different ripening stages were used in this study and randomly divided in a calibration set (505 apricots) and in a validation set (252 apricots). The most suitable region was found in the range between 1500 and 900 cm−1. Good prediction performances were obtained (R2 ? 0.74 and RMSEP ? 18%). Results concerning the prediction of other quality traits such as firmness, skin colour, ethylene production, soluble solids content and titratable acidity were discussed.  相似文献   
12.
The purpose of this study was to evaluate the impact of repeated follicular puncture used in the ovum pick-up technique on the welfare of cows. The evaluation relies on the physiological measurement of stress, milk production criteria, immune status, and the histological examination of ovaries. Two groups of five Holstein cows were submitted to epidural anaesthesia and genital palpation with insertion of an intravaginal ultrasound probe for transvaginal puncture (the puncture was not performed in the control group). Animals were manipulated twice a week for 8 weeks (16 manipulation sessions). The blood cortisol concentrations increased after each session; however, the concentrations were the same in both the control and the punctured groups. Two adrenocorticotrophic hormone challenge tests, performed before the first session and after the last session, showed an unchanged adrenal sensitivity through repeated puncture sessions. The transvaginal puncture did not affect milk production, or blood and milk somatic cell counts. Ovariectomies were performed on another group of four Holstein cows at various intervals (0 to 30 days) after five similar puncture sessions. Histological examination of the ovaries 4 days after puncture revealed blood-filled follicles and haemorrhagic foci in ovarian stroma, but the examination 30 days after the last puncture session demonstrated very limited, if any, fibrosis. On the basis of the criteria chosen for this study, repeated transvaginal follicular puncture on its own does not impact adversely on the welfare of cows.  相似文献   
13.
Old age, adiposity, and metabolic disorders are known as risk factors for chronic tendinopathy, which is a common problem in both athletes and the general population. However, the importance of these influencing factors has not yet been well understood. This study investigated alterations in gene expression and histology of Achilles tendons of young (10 weeks) and old (100 weeks) rats bred for low (low capacity runners, LCR) and high (high capacity runners, HCR) intrinsic aerobic exercise capacity. In this rat model, LCR displayed a phenotype of reduced exercise capacity, higher body weight, and metabolic dysfunctions compared to HCR. We hypothesized that the risk factors for tendinopathy in old LCR could lead to more pronounced impairments in Achilles tendon tissue. In quantitative real-time PCR (qPCR), age-related downregulation of tenocyte markers e.g., tenomodulin, genes related to matrix modeling and remodeling (e.g., collagens, elastin, biglycan, fibronectin, tenascin C) as well as transforming growth factor beta 3 (Tgfb3) have been detected. Inflammation marker cyclooxygenase 2 (Cox2) was downregulated in old rats, while microsomal prostaglandin E synthase 2 (Ptges2) was upregulated in old HCR and old LCR. In all groups, interleukin 6 (Il6), interleukin 1 beta (Il1b), and tumor necrosis factor alpha (Tnfa) showed no significant alteration. In histological evaluation, tendons of old rats had fewer and more elongated tenocyte nuclei than young rats. Even though a higher content of glycosaminoglycans, a sign of degeneration, was found in old HCR and LCR, no further signs of tendinopathy were detectable in tendons of old rats by histological evaluation. Low intrinsic aerobic exercise capacity and the associated phenotype did not show significant effects on gene expression and tendon histology. These findings indicate that aging seems to play a prominent role in molecular and structural alterations of Achilles tendon tissue and suggests that other risk factors associated with intrinsic aerobic exercise capacity are less influential in this rat model.  相似文献   
14.
A non-destructive optical method based on near-infrared spectroscopy has been used for the evaluation of apricot fruit quality. Diffuse reflectance measurements (800–2500 nm), physical, physiological and biochemical measurements were performed individually on 877 apricot fruits from eight contrasted cultivars harvested at different ripening stages. Relationships between spectral wavelengths and quality attributes were evaluated by application of chemometric techniques based on partial least squares (PLS) on fruit set divided randomly into two groups: 598 fruits for calibration and 279 for validation. Good prediction performance was obtained for soluble solids and titratable acidity with correlation coefficients of 0.92 and 0.89 respectively and root mean square errors of prediction of 0.98% Brix and 3.62 meq 100 g−1 FW respectively. For the other quality traits such as firmness, ethylene, individual sugars and organic acids, the prediction models were not satisfactorily accurate due to the high error of calibration and prediction.  相似文献   
15.
A series of 24 huprine derivatives diversely functionalized at position 9 have been synthesized and evaluated for their inhibitory activity against human recombinant acetylcholinesterase (AChE). These derivatives were prepared in one to five steps from huprine 1 bearing an ester function at position 9. Ten analogues ( 1 , 2 , 6 – 9 , 13 – 15 , and 23 ) are active in the low nanomolar range (IC50 <5 nM ), very close to the parent compound huprine X. Compounds 2 , 6 , and 7 show a very good selectivity for AChE, with AChE inhibitory activities 700–1160‐fold higher than those for butyrylcholinesterase (BChE). The inhibitory potency of these compounds decreases with the steric bulk of the substituents at position 9. According to docking simulations, small substituents fit into the acyl‐binding pocket, whereas the larger ones stick out of the active site gorge of AChE. Determination of the kinetic parameters of three of the most potent huprines ( 2 , 6 , and 7 ) showed that most of the difference in KD is accounted by a decrease in kon, which is correlated to the increase of the substituent size. A first in vivo evaluation has been performed in mice for the most active compound 2 (IC50=1.1 nM ) and showed a rather weak toxicity (LD50=40 mg kg?1) and an ability to cross the blood–brain barrier with doses above 15 mg kg?1.  相似文献   
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Belyaev  A. V.  Renard  E. V.  Khranenko  S. P.  Emel'yanov  V. A.  Fedotov  M. A. 《Radiochemistry》2002,44(6):546-558
The state of radiorhodium in liquid waste from processing of spent nuclear fuel was analyzed in detail by ESR and NMR spectroscopy on several nuclei. The most probable oxidation state of rhodium in nitric acid solutions is +3. Three procedures for preparing nitric acid solutions of rhodium were studied. The composition of Rh(III) complexes in these solutions is similar but not identical. The method for identifying the ionic composition of similar objects was proposed. The speciation of rhodium in nitric acid solutions with the acid concentration ranging from 2×10- 2 to 15 M was studied. Polynuclear oligomers with (-ONO2)2 bridges, mainly tetramers, are formed in solutions with CRh > 2 M, [NO3 -] 8 M, and [H+] 0.7 M. At CRh = (1-2)×10- 2, [NO3 -] = 1-4 M, and [H+] = 0.4-4 M, the (-OH, -ONO2) dimer and trimer prevail; at [NO3 -] < 1 M and [H+] < 0.2 M, the (-OH, -ONO2) dimer dominates. No Rh(III) aqua ion and no monomeric nitrate complexes were detected in the quasiequilibrium system at any concentrations of the components. In nitrate-nitrite solutions, both subnitrated (-OH, -ONO2) Rh(III) oligomers and mononuclear Rh(III) nitroaqua complexes exist. The equilibrium between these species is attained very slowly and depends on the equilibrium concentration of nitrite anion. Forecast was given on isolation of rhodium from nitric acid solutions of SNF by extraction, ion-exchange, electrolytic, and precipitation procedures.  相似文献   
18.
Aerosol extinction coefficients have been derived in the 375-700-nm spectral domain from measurement in the stratosphere since 1992, at night, at mid- and high latitudes from 15 to 40 km, by two balloonborne spectrometers, Absorption par les Minoritaires Ozone et NO(chi) (AMON) and Spectroscopie d'Absorption Lunaire pour l'Observation des Minoritaires Ozone et NO(chi) (SALOMON). Log-normal size distributions associated with the Mie-computed extinction spectra that best fit the measurements permit calculation of integrated properties of the distributions. Although measured extinction spectra that correspond to background aerosols can be reproduced by the Mie scattering model by use of monomodal log-normal size distributions, each flight reveals some large discrepancies between measurement and theory at several altitudes. The agreement between measured and Mie-calculated extinction spectra is significantly improved by use of bimodal log-normal distributions. Nevertheless, neither monomodal nor bimodal distributions permit correct reproduction of some of the measured extinction shapes, especially for the 26 February 1997 AMON flight, which exhibited spectral behavior attributed to particles from a polar stratospheric cloud event.  相似文献   
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