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81.
Isabel Moreno Author Vitae Author Vitae Blanca Inés Author VitaeAuthor Vitae Esther Domínguez Author Vitae 《Inorganica chimica acta》2010,363(9):1903-2932
The synthesis and catalytic activity of different pincer type palladium complexes synthesized in our laboratory are compiled in this report. The specific design of these palladacycles allows the employment of sustainable protocols and the recycle of the catalytic systems.The results obtained by our group in this context will be compared with other previously reported and new advances in this field. 相似文献
82.
Katherine S Rudolph Marty E Eastlack Michael J Axe Lynn Snyder-MacklerAuthor vitae 《Journal of electromyography and kinesiology》1998,8(6):349-362
The purpose of this study was to describe kinematic and kinetic differences between a group of ACL deficient subjects who were grouped according to functional ability. Sixteen patients with complete ACL rupture were studied; eight subjects had instability with activities of daily living (non-copers) and eight subjects had returned to all pre-injury activity without limitation (copers). Three-dimensional joint kinematics and kinetics were collected from the knee and ankle during walking, jogging and going up and over a step. Results showed that both groups mitigated the force with which they contacted the floor but non-copers consistently demonstrated less knee flexion in the involved limb. The copers used joint kinematics similar to those of their uninvolved knees and similar to knee motions reported in uninjured subjects. The reduced knee motion in the involved knee of the non-copers did not correlate directly with quadriceps femoris muscle weakness.
The data suggest that the non-copers utilize a stabilization strategy which stiffens the knee joint which not only is unsuccessful but may lead to excessive joint contact forces which have the potential to damage articular structures. The copers use a strategy which permits normal knee kinematics and bodes well for joint integrity. 相似文献
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A concentration gradient of the GTP-bound form of the GTPase Ran across nuclear pores is essential for the transport of many proteins and nucleic acids between the nuclear and cytoplasmic compartments of eukaryotic cells [1], [2], [3] and [4]. The mechanisms responsible for the dynamics and maintenance of this Ran gradient have been unclear. We now show that Ran shuttles between the nucleosol and cytosol, and that cytosolic Ran accumulates rapidly in the nucleus in a saturable manner that is dependent on temperature and on the guanine-nucleotide exchange factor RCC1. Nuclear import in digitonin-permeabilized cells in the absence of added factors was minimal. The addition of energy and nuclear transport factor 2 (NTF2) [5] was sufficient for the accumulation of Ran in the nucleus. An NTF2 mutant that cannot bind Ran [6] was unable to facilitate Ran import. A GTP-bound form of a Ran mutant that cannot bind NTF2 was not a substrate for import. A dominant-negative importin-β mutant inhibited nuclear import of Ran, whereas addition of transportin, which accumulates in the nucleus, enhanced NTF2-dependent Ran import. We conclude that NTF2 functions as a transport receptor for Ran, permitting rapid entry into the nucleus where GTP-GDP exchange mediated by RCC1 [7] converts Ran into its GTP-bound state. The Ran–GTP can associate with nuclear Ran-binding proteins, thereby creating a Ran gradient across nuclear pores. 相似文献
84.
Daniela Belli Dell’Amico Author VitaeAuthor Vitae Guido Pampaloni Author Vitae 《Inorganica chimica acta》2008,361(11):2997-3003
Examples are reported of heavier (bromides or iodides) metal halides of the d or f transition series being prepared through the halide exchange reaction from the lighter congeners (fluorides or chlorides, easily prepared by direct combination from the elements), by using gaseous hydrogen halides HX or alkyl halides RX in an anhydrous organic solvent at room temperature or even below. This represents a considerable improvement with respect to the traditional high-temperature experimental procedures from the elements. Thermodynamic data show that this synthetic route is of quite general validity. 相似文献
85.
Marcelo Camargo Saad Lilian Ramiro Felício Catia de Lourdes Masullo Rogério Ferreira Liporaci Debora Bevilaqua-GrossiAuthor vitae 《Journal of electromyography and kinesiology》2011,21(5):712-718
Anterior Knee Pain (AKP) is considered as one of the most common, yet misunderstood, knee pathologies. The aim of this study was to evaluate the displacement area of the center of pressure, Ground Reaction Force (GRF), and the electromyography activity of the hip and the quadriceps muscles in healthy and AKP individuals during the step-up and step-down exercises. Both groups (Control group and AKP group) were composed of 15 volunteers submitted to the exercises on a force plate. The AKP group presented greater displacement area of the center of pressure for all the situations evaluated than the Control group (p < 0.05), as well as a lesser magnitude of the GRF during the step-down exercise. The AKP group presented lower electromyography activity than the Control group in all situations evaluated. AKP individuals do not have muscle imbalances; they present a lower electromyography activity of the stabilizing muscles of the patella and hip and show greater instability in activities such as step up and down compared to normal subjects. 相似文献
86.
Jacek Cholewicki Jaap van Dieën Angela S. Lee N. Peter ReevesAuthor vitae 《Journal of electromyography and kinesiology》2011,21(5):767-773
The problem with normalizing EMG data from patients with painful symptoms (e.g., low back pain) is that such patients may be unwilling or unable to perform maximum exertions. Furthermore, the normalization to a reference signal, obtained from a maximal or sub-maximal task, tends to mask differences that might exist as a result of pathology. Therefore, we presented a novel method (GAIN method) for normalizing trunk EMG data that overcomes both problems. The GAIN method does not require maximal exertions (MVC) and tends to preserve distinct features in the muscle recruitment patterns for various tasks. Ten healthy subjects performed various isometric trunk exertions, while EMG data from 10 muscles were recorded and later normalized using the GAIN and MVC methods. The MVC method resulted in smaller variation between subjects when tasks were executed at the three relative force levels (10%, 20%, and 30% MVC), while the GAIN method resulted in smaller variation between subjects when the tasks were executed at the three absolute force levels (50 N, 100 N, and 145 N). This outcome implies that the MVC method provides a relative measure of muscle effort, while the GAIN-normalized data gives an estimate of the absolute muscle force. Therefore, the GAIN-normalized data tends to preserve the differences between subjects in the way they recruit their muscles to execute various tasks, while the MVC-normalized data will tend to suppress such differences. The appropriate choice of the EMG normalization method will depend on the specific question that an experimenter is attempting to answer. 相似文献
87.
Kim Hébert-Losier Anthony G. Schneiders José A. García S. John Sullivan Guy G. SimoneauAuthor vitae 《Journal of electromyography and kinesiology》2011,21(5):819-826
There is limited research on peak activity of the separate triceps surae muscles in select knee flexion (KF) positions during a maximum voluntary isometric contraction (MVIC) used to normalize EMG signals. The aim of this study was to determine how frequent peak activity occurred during an MVIC for soleus (SOL), gastrocnemius medialis (GM), and gastrocnemius lateralis (GL) in select KF positions, and if these peaks were recorded in similar KF positions. Forty-eight healthy individuals performed unilateral plantar-flexion MVIC in standing with 0°KF and 45°KF, and in sitting with 90°KF. Surface EMG of SOL, GM, and GL were collected and processed in 250 ms epochs to determine peak root-mean-square amplitude. Peak activity was most frequently captured in standing and rarely in sitting, with no position selective to SOL, GM or GL activity. Peak GM and GL activity was more frequent in 0°KF than 45°KF, and more often in similar KF positions than not. Peak SOL activity was just as likely in 45°KF as 0°KF, and more in positions similar to GM, but not GL. The EMG amplitudes were at least 20% greater in positions that captured peak activity over those that did not. The overall findings support performing an MVIC in more than one KF position to normalize triceps surae EMG. It is emphasized that no KF position is selective to SOL, GM, or GL alone. 相似文献
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古莲子与现代莲子ABA含量和SOD活性的比较研究 总被引:5,自引:0,他引:5
本研究选用种龄为 580± 70年的古莲子──太子莲 ,和与之亲缘相近的种龄为 8年的现代哈尔滨莲 ,对比测定其脱落酸的含量及超氧物歧化酶活性 ,以期探讨距今已有几百年种龄的古莲仍能保持其活力、萌发、开花的现象与这两项生理指标的关系。实验结果表明 ,两种莲子的皮 (果皮和种皮 )ABA含量均很高 ,太子莲和哈尔滨莲分别为 4.1 8μg/g ,5.69μg/g。SOD活性在莲子吸胀期和幼苗期两种莲子的子叶中差异不明显 ,而在胚和幼芽中 ,太子莲比哈尔滨莲分别高出 50 %和 2 7%。基于以上结果 ,说明其胚中具有较强的抗逆性物质 ,利于保持其生命力。莲皮中高含量的ABA及胚中高活性的SOD有利于莲子的休眠和增强其抗逆性 ,并保持胚的生命力 相似文献
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