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51.
The Nedd8 activating enzyme (NAE) launches the transfer of the ubiquitin‐like protein Nedd8 through an enzymatic cascade to covalently modify a diverse array of proteins, thus regulating their biological functions in the cell. The C‐terminal peptide of Nedd8 extends deeply into the active site of NAE and plays an important role in the specific recognition of Nedd8 by NAE. We used phage display to profile C‐terminal mutant sequences of Nedd8 that could be recognized by NAE for the activation reaction. We found that NAE can accommodate diverse changes in the Nedd8 C‐terminal sequence (71LALRGG76), including Arg and Ile replacing Leu71, Leu, Ser, and Gln replacing Ala72, and substitutions by bulky aromatic residues at positions 73 and 74. We also observed that short peptides corresponding to the C‐terminal sequences of the Nedd8 variants can be activated by NAE to form peptide~NAE thioester conjugates. Once NAE is covalently loaded with these Nedd8‐mimicking peptides, it can no longer activate full‐length Nedd8 for transfer to the neddylation targets, such as the cullin subunits of cullin‐RING E3 ubiquitin ligases (CRLs). We have thus developed a new method to inhibit protein neddylation by Nedd8‐mimicking peptides.  相似文献   
52.
Changes in the environmental perception of people of the Calcutta‐Hooghlyside industrial belt are discussed. Residents of the area are becoming increasingly aware of air and water pollution. A positive correlation exists between the frequency of their perception of air and water pollution problems and the actual level of pollution in the area.  相似文献   
53.
Reported are motivations and approaches for the integration of custom sensors with microfluidic devices for cytometry on a chip and related fluid metering applications. To demonstrate, details of a digital 16-element mixed-signal CMOS active pixel optical sensor with adaptive spatial filtering is first described. The 0.18-mum CMOS fabricated sensor is then shown coupled to a microfluidic channel via a polymer encapsulated chip-on-board approach as well as a preferred flip-chip-on-glass hybrid integration approach. However, both approaches discussed possess attributes that are well suited for reliable high-volume production. Utilizing these two disparate assembly topologies, the intelligent sensor's general behavior, optical input dynamic range, and near-field sensitivity to polymer beads being transported in a microfluidic channel is explored. The findings suggest that discrete near-field sensor integration with microfluidics is a well-positioned integration approach for helping to obviate the need for precision analog-to-digital conversion, optical fiber microchannel coupling, and conventional microscopy for a set of relevant micro total analysis system applications. By opting instead for a hybrid multichip module approach to system integration, this study marks a slight departure in strategy relative to many common monolithic system-on-chip integration efforts  相似文献   
54.
We present a robust framework for extracting lines of curvature from point clouds. First, we show a novel approach to denoising the input point cloud using robust statistical estimates of surface normal and curvature which automatically rejects outliers and corrects points by energy minimization. Then the lines of curvature are constructed on the point cloud with controllable density. Our approach is applicable to surfaces of arbitrary genus, with or without boundaries, and is statistically robust to noise and outliers while preserving sharp surface features. We show our approach to be effective over a range of synthetic and real-world input datasets with varying amounts of noise and outliers. The extraction of curvature information can benefit many applications in CAD, computer vision and graphics for point cloud shape analysis, recognition and segmentation. Here, we show the possibility of using the lines of curvature for feature-preserving mesh construction directly from noisy point clouds.  相似文献   
55.
Sketching piecewise clothoid curves   总被引:1,自引:0,他引:1  
We present a novel approach to sketching 2D curves with minimally varying curvature as piecewise clothoids. A stable and efficient algorithm fits a sketched piecewise linear curve using a number of clothoid segments with G2 continuity based on a specified error tolerance. Further, adjacent clothoid segments can be locally blended to result in a G3 curve with curvature that predominantly varies linearly with arc length. We also handle intended sharp corners or G1 discontinuities, as independent rotations of clothoid pieces. Our formulation is ideally suited to conceptual design applications where aesthetic fairness of the sketched curve takes precedence over the precise interpolation of geometric constraints. We show the effectiveness of our results within a system for sketch-based road and robot-vehicle path design, where clothoids are already widely used.  相似文献   
56.
We are introducing in this paper a digital-analog hybrid model approach for the study of a complete gene regulatory network; the heat shock response (HSR) network of eukaryotes. HSR is a crucial and widely studied cellular phenomenon occurring due to various stresses on the cell, and is characterised by the induction of heat shock genes resulting in the production of heat shock proteins (HSPs) which restores cellular homeostasis by maintaining protein integrity. We are proposing a model which incorporates simple digital and analog components which mimic the functioning of biological molecules involved in HSR and model their dynamics and behaviour. The simulation result of the circuit for the production of HSP70 has been found to be consistent with published experimental results. The qualitative behaviour of the HSR is expressed through a truth table. Through this novel approach, the authors have tried to develop a level of understanding of the interactions of the parts of the HSR system and of this system as a whole.  相似文献   
57.
One of the key structural features of a surface microfluidic (SMF) device is the surface coating, since it directly affects both the performance and reliability of the SMF device. This work examines and compares the performance of liquid dielectrophoresis (LDEP) SMF devices, fabricated with conventional spin-coated Teflon? surface to those coated with a recently developed fluoropolymer composite coating, which have been shown to be superior for low-voltage electrowetting actuation. We have focused on SMF devices that leverage LDEP and utilize high AC voltages to actuate aqueous samples on hydrophobic surfaces and produce droplet arrays of controlled size and structure to facilitate rapid and large-scale combinatorial bio-assays. Our findings demonstrate the superior performance, robustness and reliability of the composite coating over the conventional spin-coated Teflon? coating, for repeated high-voltage, high-frequency LDEP actuations for homogenous, emulsion and variable volume aqueous sample dispensing.  相似文献   
58.
In this study we present an innovative design idea for a semi-invasive blood sampling, analysis and drug delivery device called “Electronic Mosquito” (“e-Mosquito”). The major building blocks of the device are discussed. The principle of operation is described and its feasibility is demonstrated. The integration of the microsystem is outlined and its practical implementation proposed.  相似文献   
59.
Experimental kinetic data are reported for key side reactions occurring in the front end [i. e. the reaction furnace (RF) and the waste heat boiler (WHB)] of modified Claus plants used for sulfur recovery from the sour gases evolved in the treatment of natural gas. An extensive experimental study was conducted in a high temperature tubular reactor system for two important homogenous gas‐phase reactions. Firstly, experiments were carried out to study the oxidation of hydrogen sulfide and methane mixtures in the presence of oxygen. Secondly, the reaction between methane and sulfur dioxide was investigated experimentally. These results showed that methane was much less competitive for oxygen than hydrogen sulfide. Hence, in a partially oxidizing environment of a RF, data showed that methane reacted significantly with other major sulfur containing species, as secondary reactions, to form COS and especially CS2. This is highly problematic from an environmental point of view.  相似文献   
60.
Now day’s computer network is an essential part of our life. Day by day, there is a high increment in the uses of computer network applications such email, bloggers, internet group, forums, conference, youtube and online TV. The exponential increment in video applications traffic, there increases challenges of computer network and it faces various problems like shortage of memory, link failure, slow processor, time out etc. These problems may lead to network congestion. Multicast is efficient system which handles the video traffic but it also suffers with congestion problem due to design vulnerability. Many researchers are working in this burning issue and they provided various solutions such as source based, receiver based and hybrid one. In this paper, we propose an efficient multicast congestion control approach which suggests the efficient joining, leaving operation based on adaptive throughput. The simulated results show that proposed scheme provides better throughput at various parameters.  相似文献   
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