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81.
Heinis Christian; Huber Adrian; Demartis Salvatore; Bertschinger Julian; Melkko Samu; Lozzi Luisa; Neri Paolo; Neri Dario 《Protein engineering, design & selection : PEDS》2001,14(12):1043-1052
Phage display has been shown to facilitate greatly the selectionof polypeptides with desired properties by establishing a directlink between the polypeptide and the gene that encodes it. However,selection for catalytic activities displayed on phage remainsa challenge, since reaction products diffuse away from the enzymeand make it difficult to recover catalytically active phageenzymes.We have recently described a selection methodology in whichthe reaction substrate (and eventually the reaction product)is anchored on calmodulin-tagged phageenzymes by meansof a calmodulin binding peptide. Phage displaying a catalyticactivity are physically isolated by means of affinity reagentsspecific for the product of reaction. In this study, we investigatedthe efficiency of selection for catalysis by phage display,using a ligase (the Escherichia coli biotin ligase BirA) andan endopeptidase (the rat trypsin His57 相似文献
82.
A new route for obtaining 1,4-cyclooctadiene by catalytic isomerization of 1,5-cyclooctadiene at low temperature in presence
of H2 in a three-phase reactor is presented. Wei, Prater and Silvestri methods are used for the kinetic studies. A comparison of
the activity-selectivity patterns of the Pd/pumice catalysts with Pd on silica and Pt and Pd–Pt on pumice catalysts is performed.
Although Pt catalysts are not active in the hydro-isomerization of 1,5-cyclooctadiene, the presence of small amount of Pt
in Pd/pumice catalysts increases the yield to 1,4-cyclooctadiene. Besides the catalyst characteristics, temperature and H2 pressure influence the production of 1,4-cyclooctadiene. A mechanism of the process is proposed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
83.
Graves Franklynn C.; Wallen Kim; Maestripieri Dario 《Canadian Metallurgical Quarterly》2002,116(3):489
This study investigated the role of the endogenous opioid system in maternal and affiliative behavior of group-living rhesus macaque (Macaca mularta) mothers with a history of abusive parenting. 18 mothers received an injection of the opioid antagonist naltrexone or saline for 5 days per wk for the first 4 wks of the infant's life. After treatment, mother-infant pairs were focally observed. Naltrexone did not significantly affect infant abuse or other measures of maternal behavior. Naltrexone increased the amount of grooming received by mothers from other group members and reduced the mothers' rate of displacement activities such as scratching, yawning, and self-grooming. These results concur with previous primate studies in suggesting that opioids mediate the rewarding effects of receiving grooming and affect anxiety-related behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
84.
Development and Experimental Analysis of a Soft Compliant Tactile Microsensor for Anthropomorphic Artificial Hand 总被引:1,自引:0,他引:1
Beccai L. Roccella S. Ascari L. Valdastri P. Sieber A. Carrozza M.C. Dario P. 《Mechatronics, IEEE/ASME Transactions on》2008,13(2):158-168
This paper presents the development and preliminary experimental analysis of a soft compliant tactile microsensor (SCTM) with minimum thickness of 2 mm. A high shear sensitive triaxial force microsensor was embedded in a soft, compliant, flexible packaging. The performance of the whole system, including the SCTM, an electronic hardware and a processing algorithm, was evaluated by static calibration, maximum load tests, noise and dynamic tests, and by focusing on slippage experiments. A proper tradeoff between final robustness and sensitivity of the tactile device was identified. The experiments showed that the tactile sensor is sufficiently robust for application in artificial hands while sensitive enough for slip event detection. The sensor signals were elaborated with the cumulative summation algorithm and the results showed that the SCTM system could detect a slip event with a delay from a minimum of 24.5 ms to a maximum of 44 ms in the majority of experiments fulfilling the neurophysiological requirement. 相似文献
85.
Shaghayegh Baradaran Ghavami Hamid Asadzadeh Aghdaei Dario Sorrentino Shabnam Shahrokh Maryam Farmani Fatemeh Ashrafian Maria Pina Dore Shahrbanoo Keshavarz Azizi Raftar Seyed Mobin Khoramjoo Mohammad Reza Zali 《International journal of molecular sciences》2021,22(15)
Inflammatory bowel diseases (IBDs) are immune-mediated, chronic relapsing diseases with a rising prevalence worldwide in both adult and pediatric populations. Treatment options for immune-mediated diseases, including IBDs, are traditional steroids, immunomodulators, and biologics, none of which are capable of inducing long-lasting remission in all patients. Dendritic cells (DCs) play a fundamental role in inducing tolerance and regulating T cells and their tolerogenic functions. Hence, modulation of intestinal mucosal immunity by DCs could provide a novel, additional tool for the treatment of IBD. Recent evidence indicates that probiotic bacteria might impact immunomodulation both in vitro and in vivo by regulating DCs’ maturation and producing tolerogenic DCs (tolDCs) which, in turn, might dampen inflammation. In this review, we will discuss this evidence and the mechanisms of action of probiotics and their metabolites in inducing tolDCs in IBDs and some conditions associated with them. 相似文献
86.
Heather F. Jackson Daniel D. Jayaseelan William E. Lee Michael J. Reece Fawad Inam Dario Manara Carlo Perinetti Casoni Franck De Bruycker Konstantinos Boboridis 《International Journal of Applied Ceramic Technology》2010,7(3):316-326
Melting temperatures of zirconium carbide were investigated in validating a novel thermal analysis technique for refractory materials. Commercial ZrC0.96 powder was densified by spark plasma sintering to >96% relative density after 6–30 min at 2173–2453 K under 40–100 MPa. Sintered ceramics were heated to >4000 K via pulsed laser heating. Mean values for solidus and liquidus transitions were 3451 and 3608 K, respectively, in fair agreement with the present phase diagram. Postmelting analysis revealed dendritic microstructure and composition consistent with single-phase ZrC. Subsurface gas porosity and ZrC–C eutectic indicate complex processes occurring during melting and freezing. 相似文献
87.
88.
The performance of mixed bi-material electrodes composed of the battery material, LiMn2O4, and the electrochemical capacitor material, activated carbon, for hybrid electrochemical energy storage devices is investigated by galvanostatic charge/discharge and pulsed discharge experiments. Both, a high and a low conductivity lithium-containing electrolyte are used. The specific charge of the bi-material electrode is the linear combination of the specific charges of LiMn2O4 and activated carbon according to the electrode composition at low discharge rates. Thus, the specific charge of the bi-material electrode falls between the specific charge of the activated carbon electrode and the LiMn2O4 battery electrode. The bi-material electrodes have better rate capability than the LiMn2O4 battery electrode. For high current pulsed applications the bi-material electrodes typically outperform both the battery and the capacitor electrode. 相似文献
89.
A demand-assignment algorithm based on a Markov modulated chain prediction model for satellite bandwidth allocation 总被引:1,自引:0,他引:1
This article deals with the problem of the design of a control-based demand-assignment algorithm for a satellite access network
using a Markov modulated chain traffic prediction model. The objective is to guarantee a target Quality of Service (QoS) to
Internet traffic, while efficiently exploiting the air interface. The proposed algorithm is in charge of dynamically partitioning
the uplink bandwidth capacity in a satellite spotbeam among the in-progress connections. Such partition is performed aiming
at matching the QoS requirements of each connection and maximizing the satellite bandwidth exploitation. A closed-loop Control
Theory approach is adopted to efficiently tackle the problem of the delay between bandwidth requests and bandwidth assignments,
while minimizing the signaling overhead caused by control messages. The algorithm efficiently copes with both the satellite
propagation delay and the delays inherent in the periodic nature of the bandwidth request mechanism. The proposed demand-assignment
algorithm and Markov chain traffic prediction model are shown to improve the overall satellite network performance through
extensive simulation experiments. 相似文献
90.
Steerable miniature jumping robot 总被引:2,自引:0,他引:2
Mirko Kovač Manuel Schlegel Jean-Christophe Zufferey Dario Floreano 《Autonomous Robots》2010,28(3):295-306
Jumping is used in nature by many small animals to locomote in cluttered environments or in rough terrain. It offers small
systems the benefit of overcoming relatively large obstacles at a low energetic cost. In order to be able to perform repetitive
jumps in a given direction, it is important to be able to upright after landing, steer and jump again. In this article, we
review and evaluate the uprighting and steering principles of existing jumping robots and present a novel spherical robot
with a mass of 14 g and a size of 18 cm that can jump up to 62 cm at a take-off angle of 75°, recover passively after landing,
orient itself, and jump again. We describe its design details and fabrication methods, characterize its jumping performance,
and demonstrate the remote controlled prototype repetitively moving over an obstacle course where it has to climb stairs and
go through a window. (See videos 1–4 in the electronic supplementary material.) 相似文献