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Membrane proteins are extremely challenging to produce in sufficient quantities for biochemical and structural analysis and there is a growing demand for solutions to this problem. In this study we attempted to improve expression of two difficult-to-express coding sequences (araH and narK) for membrane transporters. For both coding sequences, synonymous codon substitutions in the region adjacent to the AUG start led to significant improvements in expression, whereas multi-parameter sequence optimization of codons throughout the coding sequence failed. We conclude that coding sequences can be re-wired for high-level protein expression by selective engineering of the 5′ coding sequence with synonymous codons, thus circumventing the need to consider whole sequence optimization.

A dual-zone reinforcement ply stacking sequence optimization method used for comosite laminate with large cutout is present. The optimization method utilized a new Genetic Algorithm. The new Genetic Algorithm introduced a new strategy which can improve the efficiency of the traditional Genetic Algorithm and overcome the shortages of the worse convergency and prematurity of the Simple Genetic Algorithm. In the new Genetic Algorithm, the selection probability and the mutation probability are self-adaptive. Compared with the Simple Genetic Algorithm, the new Genetic Algorithm method shows good consistency, fast convergency and practical feasibility. By using the new Genetic Algorithm, the reinforcement ply stacking sequence optimization method got reasonable symmetric and balance stacking sequence which could meet the design requirements.

Magnetic resonance imaging (MRI) is an imaging technique that is based on the interactions of water with external magnetic fields. Magnetic properties of water molecules are analyzed in order to sketch the profile of tissues, and they may be related to a variety of aspects including internal structure, tissue integrity, molecular environment, and others. In order to elucidate tissue properties, it is often necessary to acquire multiple series of images and quantify the progress of a certain parameter in time or the degree of response to an external perturbation. After careful sequence optimization in order to selectively trigger the process, one needs to appreciate all the possible factors affecting the evolution in order to constitute a robust model. Complex phenomena taking place after excitation are decomposed in one or more mathematical terms of an appropriate form and weighting, to comply with the physical rules behind the sequence of events taking place. When model predicted data converge to the experimental measurements, the model can be considered as reliable, in the frame of a carefully designed imaging protocol. In this chapter, we will focus on the most important models used to extract imaging biomarkers related to diffusion and perfusion studies.

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Contexto: Existe, actualmente, uma incessante necessidade por exames imagiológicos melhores e mais rápidos no campo da Ressonância Magnética Imagiológica (RMI) clinica. Isto é particularmente verdade em RMI músculo-esquelética (MSK), na qual longas listas de espera são um problema constante. Para além disto, fundos para adquirir ou actualizar equipamentos imagiológicos encontram-se totalmente ou parcialmente cortados, devido à difícil situação financeira na qual a maioria dos Sistemas de Saúde se encontra. Este projecto pretende avaliar se e até que ponto a Optimização de Sequências de RMI pode ser uma resposta ao desafio de melhorar a qualidade de imagem (QI) e reduzir o Tempo de Aquisição (TA) sem recurso a investimento financeiro. Metodologia: Foram criadas Sequências Optimizadas (SO), para scanners de 1,5 e 3 Tesla, que se focaram em obter a melhor relação QI/TA. As SO foram desenvolvidas pegando em sequências RMI genéricas, já disponibilizadas pelos fabricantes nos scanners, e depois manipulando os seus parâmetros RMI através de um processo iterativo, em conjunção com várias antenas RMI receptoras e fantomas de RMI biológicos e não biológicos. Após a melhor relação QI/TA ter sido estabelecida, para cada sequência, estas foram usadas para criar réplicas dos protocolos padrão do Departamento de RMI. A diferença em TA entre os protocolos velhos e os novos foi calculada para medir a redução de TA obtida. A mudança em QI foi avaliada através análise visual retrospectiva efectuada por avaliadores cegos, os quais tinham extensa experiência em RMI MSK. As respostas dos avaliadores foram registadas através de um questionário padrão que se focou na QI geral e em aspectos técnicos específicos (exemplo: Resolução Espacial, Contraste, Artefactos, etc.) Resultados: A redução média no TA foi de 6 minutos e 48 segundos por exame. Esta redução intensificou-se em protocolos com um maior número de sequências. T1 foi a ponderação que demonstrou maior redução do TA. No geral os avaliadores consideraram que as imagens obtidas com SO tinham melhor ou muito melhor QI que as imagens obtidas com sequências não optimizadas. Esta tendência esteve também presente para todos os aspectos técnicos de QI avaliados (p

The purpose of the study was to identify the frequency and reasons for extra sequences in clinical liver MRI and MRCP examinations. A total of 250 consecutive liver MRI and 250 consecutive MRCP examinations performed at a single institution were reviewed. Extra sequences performed in comparison with our standard institutional protocol were identified. Reasons for the extra sequences were identified. Overall trends were assessed. In significantly greater fractions of exams (p = 0.009–0.030), MRCP had ≥1 extra sequence (40.8% vs. 29.2%) and ≥2 extra sequences (16.0% vs. 5.6%) in comparison with the institutional protocol than did liver MRI. The average number of extra sequences was significantly higher (p = 0.004) for MRCP (0.73 ± 1.2) than liver MRI (0.44 ± 0.88). Reasons for extra sequences were as follows: sequence repeated for patient motion (33.8% for liver MRI; 31.9% for MRCP); sequence repeated for anatomic coverage (24.3% for liver MRI; 19.8% for MRCP); sequence added by the radiologist (15.3% for liver MRI; 33.0% for MRCP); sequence repeated for other reason (17.1% for liver MRI; 12.6% for MRCP); and sequence added by the technologist (5.4% for liver MRI; 2.7% for MRCP). The most commonly repeated sequence due to motion was the axial fat-saturated turbo spin-echo T2-weighted sequence for both liver MRI and MRCP (54.7% and 29.3% of sequences repeated due to motion, respectively). For liver MRI and MRCP exams, sequences were most often repeated due to motion artifact (most often occurring on TSE T2WI), and sequences were most often added by the radiologist. The findings may help guide sequence optimization, quality improvement initiatives, and standardization of operations, for improving efficiency in abdominal MRI workflow.

By using an accurate switching model it's possible to adjust the thermal distribution between the semiconductors and increase the output power of the converter for Active Neutral Point Clamped converters [1]. In this paper the study of switching sequence optimization for 3 Level ANPC converters is extended to analyze the performance of the converter under different cooling water inlet temperatures and different water/glycol mixtures of the cooling water.

Proteins that bind small molecules (ligands) can be used as biosensors, signal modulators, and sequestering agents. When naturally occurring proteins for a particular target ligand are not available, artificial proteins can be computationally designed. We present a protocol based on Rosetta Ligand to redesign an existing protein pocket to bind a target ligand. Starting with a protein structure and the structure of the ligand, Rosetta can optimize both the placement of the ligand in the pocket and the identity and conformation of the surrounding sidechains, yielding proteins that bind the target compound.

Optimizing the laminates of large composite structures is nowadays well-recognized as having significant benefits in the design of lightweight structural solutions. However, designs based on locally optimized laminates are prone to structural discontinuities and enforcing blending during the optimization is therefore crucial in order to achieve structurally continuous and ready-to-manufacture designs. Bi-step strategies, relying on a continuous gradient-based optimization of lamination parameters followed by a discrete stacking sequence optimization step during which blending is enforced, have been proposed in theliterature. However, significant mismatch between continuous and discrete solutions were observed due to the discrepancies between both design spaces. The present paper highlights the capability of the continuous blending constraints, recently proposed by the authors, in reducing the discrepancies between discrete and continuous solutions. The paper also demonstrates that more realistic optimal continuous designs are achieved thanks to the application of the blending constraints during the aeroelastic optimization of a variable stiffness wing. Additionally, the proposed blending constraints have been applied to NASTRAN SOL 200 showing their ease of implementation in commercial software.

By making full use of the advantages of strip mining method and full-pillar mining method, the wide strip and full-pillar mining method can achieve the aim of mining under villages. However, at the full-pillar mining stage, the difficulty in managing several workfaces which are at work at the same time still exists. To improve the wide strip and full-pillar mining method’s applicability, an optimization of extraction sequence for coal pillars instead of the multi-working-face is put forward at the stage of full-pillar mining, and in the case of the deformation limit of surface structures is satisfied, to extract all the coal pillars which are under villages. By specific analysis of the extraction sequence optimization of the coal pillars in No.1 mine under Qian Xudapo village which belongs to Chang Chun coal Co., LTD., a better result is got which also acts a technological reference for the extraction under villages.

Purpose: To implement a method using an extended phase graph (EPG)-based simulation to optimize inversion-prepared gradient echo sequences with respect to signal and contrast within the shortest acquisition time. Materials and Methods: A critical issue in rapid gradient-echo imaging is the effect of residual transverse magnetization between consecutive data acquisition windows. Various spoiling schemes have been proposed to mitigate this problem, and while spoiling is often considered to be perfect, imaging can be more truthfully described using the EPG. An EPG-based simulation is used to analyze and predict the image signal and contrast to serve as a basis for sequence optimization. Results: Fourteen biological phantom experiments and five brain imaging experiments on each of five healthy volunteers was performed to validate and verify the accuracy of the EPG-based simulation. In addition, two experiments on an in-cranial cadaver brain were performed to show the ability of the proposed method for improving overall image quality. Conclusion: From the experiment results, it is demonstrated that optimization of 3D magnetization-prepared rapid gradient-echo imaging sequences can be performed with an EPG-based simulation to manipulate the sequence parameters for generating images with highly specific signal and contrast characteristics for quantitative T1-weighted human brain imaging. J. Magn. Reson. Imaging 2012;36:748–755. © 2012 Wiley Periodicals, Inc.

Introduction Liver imaging is challenging due to its constant movement with breathing. In Magnetic Resonance Imaging (MRI), different strategies have been developed for organ movement consideration [1] , [2] , [3] . These methods are limited by the temporal resolution, as well as image quality. A novel retrospective gating method for dynamic 3D MR imaging during free breathing was developed [1] and further improved by Celicanin et al. [4] . This work aims of assessing the method and the reconstruction technique for liver cases. The final clinical application is to improve liver lesion delineation for Stereotactic Body Radiation Therapy (SBRT). Methods The innovative 4D MRI approach has been evaluated for liver motion estimation during entire respiratory cycle on a healthy volunteer. It is based on simultaneous acquisition of 2D images and a navigator set using acceleration CAIPIRINHA technique [4] providing no temporal divergence between them. During the entire acquisition time, the navigator is fixed in the same position, while the image position is changing, in order to cover the entire organ during free breathing [1] . The entire respiratory cycle is acquired, using a modified balanced Steady State Free Precession sequence (bSSFP) and is reconstructed in a retrospective manner ( Fig. 1 ). Images are acquired with a 1.5T MRI (MAGNETOM Aera; Siemens Medical Solutions, Erlangen, Germany), using an 18-channel design body flex coil. The 3.5 mm 2D axial slices are obtained, using the following sequence parameters: TE = 2.27 ms, TR = 591.97 ms, FA = 70 °, FOV = 37 × 37 cm2, matrix = 256 × 246. Total acquisition time is 33.175 s (0.83 s per slice). Results The preliminary results obtained on a healthy volunteer are shown in Fig. 1 . Images are characterized by high resolution and great contrast, making this method promising for liver lesion examination. The reconstruction of 4D MRI and the sequence optimization to cover the entire respiration cycle with the appropriate time sampling is ongoing work. Conclusions The benefit of MRI acquisition in treatment position to improve lesion contouring for liver SBRT has already been demonstrated [5] . The presented 4D MRI method represents a highly time efficient technique for the free breathing liver motion registration, giving the possibility to sort and reconstruct the images according to the respiratory phases. It will allow registration with 4D CT planning, likely to improve delineation accuracy. The same approach can be applied to study moving organs others than liver.

In this paper, the traditional steel engine hood is analyzed using finite element method firstly, and then the basic performance requirements of the hood is obtained. Based on the principle of equal stiffness, the design process is executed on carbon fiber composite hood. Afterwards according to the property of this composite, the whole optimization process of composite hood from conceptual design to detailed design is accomplished by ways of free size optimization, parameters optimization and stacking sequence optimization. The optimal structure of carbon fiber composite engine hood can be obtained by comparing the results of optimization design. Carbon fiber can put lightweight into practice , and the developing time of composite hood can be sharply reduced .

The ‘manufacturer-internal relationship optimization model (MIROM)’, a schematic framework for internal relationship, is proposed for the manufactured housing (MH) factory. This model emphasizes the relationship between customer order from retailers (i.e., customized MH) and the production process, indicating that these elements are not mutually exclusive. In particular, through surveys and site visits, the planning of the product mix and sequence in the MH factory is considered the most critical area of the MIROM framework. This paper aims to convey how these areas can be elevated to the planning level with innovative changes and optimization. A product mix optimization model with linear programming was developed and a sequence optimization model was created by incorporating just-in-time (JIT) approaches. The proposed strategic MIROM framework and the specific optimization models can contribute to achieving significant improvement in the internal MH production planning. It can be applied for the site-built housing industry with similar industrialized environments depending on the scale of the operation.

A fast and robust methodology for in vivo T2 mapping is presented. The approach is based on the partially spoiled steady state free precession technique recently proposed by Bieri et al. (Magn Reson Med 2011). The accuracy of this method was demonstrated in simulations and phantom experiments. Variations in skeletal muscle T2 relaxation time have been correlated with cell damage and inflammatory response. Nonetheless, the lack of easily implementable, fast, accurate and reproducible methods has hampered the adoption of T2 measurement as a noninvasive tool for skeletal muscle characterization. The applicability of the partially spoiled steady state free precession method for tissue characterization in muscle disease is illustrated in this work by several examples. Quantitative MRI, in particular T2 mapping based on partially spoiled steady state free precession acquisitions, might provide objective markers of muscle damage and degenerative changes, and an alternative to serial muscle biopsies. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.

Semiempirical calculations were performed on complexes of 4-substituted-2,2′;6′,2′′-terpyridino group III and group IV elements. The energy values obtained for the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) were subjected to conditional sequence optimization (LUMODONOR < LUMOACCEPTOR and HOMODONOR < HOMOACCEPTOR). The virtual libraries of candidate antennas obtained were subjected to screening to find the structures with the highest drop potential and obtain the lead antennas. Hence, this study demonstrates the application of combinatorial principles in the field of optoelectronics.

Laminated composite structures are widely used for aerospace components because of their high specific strength and specific stiffness. For laminated composite structures, stacking sequence optimization is indispensable. Although fracture of the laminated composites is usually used as a constraint, it is very important to obtain an accurate approximation of the fracture of the laminated composites for the optimization of surrogate models. Approximating the fracture of laminated composites, however, is quite difficult because the fracture index is very noisy. In the present study, a new surrogate model using the Kriging model for the fracture of laminated composites is proposed and tested for the most severe plate bending problems.

As the travel time covers a substantial part of picking processes in warehouses, an appropriate sequencing of picking lines within a batch is crucial to achieve high efficiency. Routing heuristics for line sequencing in order picking batches are well researched, documented and implemented in today's Warehouse Management Systems (WMS). For storage areas in practice where routing heuristics could hardly be applied, an optimisation routine could be an alternative. Based on a digitised network, the Line Sequence Optimisation (LSO) calculates the line sequence for a given batch with the minimum travel time. For a case study at a distributor in the electronic devices business segment, the quantitative evaluation showed an overall improvement potential of 7,4%. But in contrast to systematically working heuristics for routing, the sequences generated by the LSO may look illogical to the picker - a qualitative evaluation needs to follow to identify sequence patterns and to discuss the methodology with the picking personnel.

The permutation algorithm with simulated annealing is proposed for the laser antimissile problem. The attacking sequence optimization plays an important role in the real-time laser antimissile problem. When faced with many targets, it is clearly essential for the laser antimissile system to determine the sequence of the attacking targets. In order to maximize attacking targets are destroyed. This paper presents a permutation algorithm based on the simulated annealing method. The permutation algorithm includes of two exchange strategies which are adjacent exchange and symmetric exchange. Finally, taking ten targets as an example, the simulation results show that the proposed algorithm has better solution than that of pure permutation algorithm and this achievement can be used in the real application.

Systematic Monte Carlo simulations of simple lattice models show that the final stage of protein folding is an ordered process where native contacts get locked (i.e., the residues come into contact and remain in contact for the duration of the folding process) in a well-defined order. The detailed study of the folding dynamics of protein-like sequences designed as to exhibit different contact energy distributions, as well as different degrees of sequence optimization (i.e., participation of non-native interactions in the folding process), reveals significant differences in the corresponding locking scenarios—the collection of native contacts and their average locking times, which are largely ascribable to the dynamics of non-native contacts. Furthermore, strong evidence for a positive role played by non-native contacts at an early folding stage was also found. Interestingly, for topologically simple target structures, a positive interplay between native and non-native contacts is observed also toward the end of the folding process, suggesting that non-native contacts may indeed affect the overall folding process. For target models exhibiting clear two-state kinetics, the relation between the nucleation mechanism of folding and the locking scenario is investigated. Our results suggest that the stabilization of the folding transition state can be achieved through the establishment of a very small network of native contacts that are the first to lock during the folding process.

In this paper, we create a framework for training-based channel estimation under different channel and interference statistics. The minimum mean square error (MMSE) estimator for channel matrix estimation in Rician fading multi-antenna systems is analyzed, and especially the design of mean square error (MSE) minimizing training sequences. By considering Kronecker-structured systems with a combination of noise and interference and arbitrary training sequence length, we collect and generalize several previous results in the framework. We clarify the conditions for achieving the optimal training sequence structure and show when the spatial training power allocation can be solved explicitly. We also prove that spatial correlation improves the estimation performance and establish how it determines the optimal training sequence length. The analytic results for Kronecker-structured systems are used to derive a heuristic training sequence under general unstructured statistics. The MMSE estimator of the squared Frobenius norm of the channel matrix is also derived and shown to provide far better gain estimates than other approaches. It is shown under which conditions training sequences that minimize the non-convex MSE can be derived explicitly or with low complexity. Numerical examples are used to evaluate the performance of the two estimators for different training sequences and system statistics. We also illustrate how the optimal length of the training sequence often can be shorter than the number of transmit antennas. © 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. QC 20100525

Precision machining of thin-walled complex components has been a serious challenge, and the machining errors are mainly due to cutting force which can induce tool-workpiece deformation and chatter vibration phenomenon. Based on the principle of stiffness optimization and material removal sequence optimization, rigidity of thin-walled component is greatly improved with non-uniform allowance distribution and spiral milling process techniques.

Magnetic Resonance Imaging is becoming more widely available and increasingly important for imaging the neonatal brain. In newborn infants it poses challenges regarding patient preparation, safety, optimal timing, and sequence optimization. These issues are addressed in this paper and indications for performing neonatal Magnetic Resonance Imaging are presented.

The application of monoclonal antibodies as commercial therapeutics poses substantial demands on stability and properties of an antibody. Therapeutic molecules that exhibit favorable properties increase the success rate in development. However, it is not yet fully understood how the protein sequences of an antibody translates into favorable in vitro molecule properties. In this work, computational design strategies based on heuristic sequence analysis were used to systematically modify an antibody that exhibited a tendency to precipitation in vitro. The resulting series of closely related antibodies showed improved stability as assessed by biophysical methods and long-term stability experiments. As a notable observation, expression levels also improved in comparison with the wild-type candidate. The methods employed to optimize the protein sequences, as well as the biophysical data used to determine the effect on stability under conditions commonly used in the formulation of therapeutic proteins, are described. Together, the experimental and computational data led to consistent conclusions regarding the effect of the introduced mutations. Our approach exemplifies how computational methods can be used to guide antibody optimization for increased stability.

Purpose To develop and validate a novel delivery strategy for reducing the respiratory motion–induced dose uncertainty of spot-scanning proton therapy. Methods and Materials The spot delivery sequence was optimized to reduce dose uncertainty. The effectiveness of the delivery sequence optimization was evaluated using measurements and patient simulation. One hundred ninety-one 2-dimensional measurements using different delivery sequences of a single-layer uniform pattern were obtained with a detector array on a 1-dimensional moving platform. Intensity modulated proton therapy plans were generated for 10 lung cancer patients, and dose uncertainties for different delivery sequences were evaluated by simulation. Results Without delivery sequence optimization, the maximum absolute dose error can be up to 97.2% in a single measurement, whereas the optimized delivery sequence results in a maximum absolute dose error of ≤11.8%. In patient simulation, the optimized delivery sequence reduces the mean of fractional maximum absolute dose error compared with the regular delivery sequence by 3.3% to 10.6% (32.5-68.0% relative reduction) for different patients. Conclusions Optimizing the delivery sequence can reduce dose uncertainty due to respiratory motion in spot-scanning proton therapy, assuming the 4-dimensional CT is a true representation of the patients' breathing patterns.

Scheduling optimization of manufacturing processes becomes more and more important. Complex models with a lot of constraints cause a higher computational effort of the simulation. Optimization cycles of heuristic optimization algorithms like genetic algorithms or local search strategies can easily be scheduled in parallel. But recurrent requirements are the distribution of the model, the interchange of the parameters and results. The IP Multicast architecture is an ideal platform for distributing model data over the network. It reduces the network overhead for sending the model to different clients and simplifies also the initial setup between client and server. The client and the server are able to find each other automatically by preconcerted multicast channels. The developed test implementation is designed to work with the simulation system simcron MODELLER and will be used to handle typical optimization tasks like the weekly demand plan of a back-end process or optimal batch sizes for burn-in ovens. It is also suitable for educational purposes and we use it in practical courses where students learn more about factory scheduling. The system offers a high reusability for any operating sequence optimization problem in electronic or semiconductor manufacturing industry, as well as in other fields.

Efficient use of fiber-reinforced polymer (FRP) composites in civil structures will require developing new forms that are conducive to their dominant in-plane mechanical properties. For this goal, an approach for the shape and stacking sequence optimization of free-form FRP shells was developed. The process was uncoupled into continuous- and discrete-variable problems and implemented in a two-level procedure: shape and laminate-property optimization followed by laminate stacking sequence optimization. Examples show the benefits of integrated shape and laminate optimization for FRP structures, and validate the method for the mixed variable problem and for different number of plies and intervals of ply orientations.

Plasma displays represent gray levels by pulse number modulation technique, which results in unfavorable dynamic false contour (DFC) on moving images. The paper proposes a method to reduce the DFC by optimizing the sub-field sequence. Sub-fields are arranged according to the descending order of the weight-modulated sub-field histogram. This sub-field arrangement has a quasi-stretched-out property. Simulation results show that the method provides a good solution for both reducing the DFC and improving the gray level expression.

Clinical MR systems operating at 3.0 Tesla have the potential to significantly improve spatial resolution due to the boost in intrinsic signal to noise ratio. However, body imaging at these field strengths presents a number of technical challenges. We performed a prospective pilot study in which 10 patients underwent an MR cholangiopancreatography (MRCP) examination consecutively on 1.5 and 3.0 Tesla systems (both Philips Intera). An axial half Fourier segmented turbo spin echo (HASTE) sequence and a coronal thick-slab 2D turbo-spin echo (TSE) sequence were compared on both systems. A reader measured the signal intensity (SI) ratios of common bile duct (CBD): liver, and CBD: fat on HASTE images and CBD: liver on the TSE images. A second reader performed a qualitative analysis of the intrahepatic and extrahepatic biliary anatomy. Quantitative data was compared using the paired t-test and qualitative data with the paired Wilcoxon signed rank test with p < 0.05. The quantitative analysis of the HASTE sequences showed a slightly higher signal intensity ratio (CBD:liver) at 3.0 Tesla compared with 1.5 Tesla (8.1 vs 5.6, p = 0.002). No significant difference was found between the SI ratios of (CBD:fat) on HASTE images or (CBD:liver) on TSE images. The qualitative analysis showed superior image quality of 3.0 Tesla over 1.5 Tesla images on both HASTE (31 vs 25, p = 0.032), and TSE sequences (34 vs 28, p = 0.043). This pilot study shows that MRCP is feasible at 3.0 Tesla with some improvement in image quality and signal characteristics. Further development may be achieved with sequence optimization and improved coil design.

The solution of combinatorial optimization problems usually involves the consideration of many possible design configurations. This often makes such approaches computationally expensive, especially when dealing with complex finite element models. Here a surrogate model is proposed that can be used to reduce substantially the computational expense of sequential combinatorial finite element problems. The model is illustrated by application to a weld path planning problem.

In this article, a fundamental aspect of protein engineering called into question: Is it really possible to computationally redesign the sequence of a protein so as to improve its stability? Specifically, the case where almost all protein's sequence is allowed to change to any other residue type is considered. The aim is to highlight two conflicting schools of thought. First, there are compelling fundamental reasons why protein design should not be possible by optimizing a conventional energy‐like function. Second, there is evidence that it is possible and has been done in practice.

This study reports proton relaxation times of water and metabolites in soleus and tibialis anterior muscles of young healthy volunteers at 3 T. The results are in agreement with data reported for 1.5 and 4 T, showing a steady increase of spin-lattice relaxation times of water, creatine and lipids with B(0) and no effect of B(0) on spin-spin relaxation. Comparison between muscles revealed a longer spin-spin relaxation time of water in soleus than in tibialis anterior muscle (31+/-1 ms vs. 28+/-1 ms, p

We show that the optimum length-/spl nu/ guard sequence for block transmission over a linear Gaussian-noise dispersive channel with memory /spl nu/ is a linear combination of the N information symbols of the block. A closed-form expression for the optimum guard sequence is derived subject to a total average energy constraint on the information and guard symbols. The achievable channel block throughput with the optimum guard sequence is compared with that achievable with two common guard sequence types, namely zero stuffing and cyclic prefix.

Summary β-Amino acids offer attractive opportunities to develop biologically active peptidomimetics, either employed alone or in conjunction with natural α-amino acids. Owing to their potential for unique conformational preferences that deviate considerably from α-peptide geometries, β-amino acids greatly expand the possible chemistries and physical properties available to polyamide foldamers. Complete in silico support for designing new molecules incorporating non-natural amino acids typically requires representing their side-chain conformations as sets of discrete rotamers for model refinement and sequence optimization. Such rotamer libraries are key components of several state-of-the-art design frameworks. Here we report the development, incorporation in to the Rosetta macromolecular modeling suite, and validation of rotamer libraries for β 3 -amino acids.

In cloud manufacturing environment, many manufacturing enterprises will produce massive data of a variety of forms. We do research of optimization parallel frequent pattern mining algorithm based on Mahout in this paper. We first analyze the implement and defects of PFP-Growth in Mahout. Then we propose two optimization strategies. One is parallel sequence optimization, and another is optimization the storage of counting information. Datasets from real manufacturing and Webdocs show the effectiveness of the strategy in time and space of the optimization.

In this work we present an overview of the main advances in column sequence optimization in zeotropic systems, ranging from systems using only conventional columns, each with a condenser and a reboiler, to fully thermally coupled systems with a single reboiler and a single condenser in the entire sequence. We also review the rigorous design of distillation columns, or column sequences. In all of the cases we focus on mathematical programming approaches.

For the purpose of improving assembly task productivity, a multirobot assembly system has been introduced. In this system, multirobots operate simultaneously and transfer parts from the part feeders to the printed circuit boards (PCBs) moving at a constant speed on the conveyor line. To exploit the capacity of this system to the full, the system should be set up with an optimal conveyor line speed and each robot should be operated along a proper assembly sequence. In this paper, a dual-robot assembly system is considered, and an efficient algorithm for concurrent optimization of conveyor line speed and assembly sequence is developed. Various evolution algorithms are tried as an optimization method, and, based on the results, the optimal conveyor line speed and assembly sequence are obtained. When using the optimized conveyor line speed and assembly sequence, the operation time can be reduced by up to 22.8 per cent compared with the initial set-up.

In this study, a modular concept for NMR hybrid imaging is presented. This concept essentially integrates different imaging modules in a sequential fashion and is therefore called CAT (combined acquisition technique). CAT is not a single specific measurement sequence, but rather a sequence design concept whereby distinct acquisition techniques with varying imaging parameters are employed in rapid succession in order to cover k-space. The power of the CAT approach is that it provides a high flexibility toward the acquisition optimization with respect to the available imaging time and the desired image quality. Important CAT sequence optimization steps include the appropriate choice of the k-space coverage ratio and the application of mixed bandwidth technology. Details of both the CAT methodology and possible CAT acquisition strategies, such as FLASH/EPI-, RARE/EPI- and FLASH/BURST-CAT are provided. Examples from imaging experiments in phantoms and healthy volunteers including mixed bandwidth acquisitions are provided to demonstrate the feasibility of the proposed CAT concept.

Ziel: Methodische Erweiterung einer 1H-MR-spektroskopischen Bildgebungssequenz (1H-2D-CSI) fur die Erkennung von Prostatakarzinomen und Validierung anhand postoperativ angefertigter histologischer Schnitte. Methoden: Eine 1H-2D-CSI-Sequenz wurde zusatzlich mit einer frequenzselektiven Fettunterdruckung ausgestattet und bei 18 Patienten (Voxelgrose: 1 cm3) bei 1,5 Tesla eingesetzt. Ergebnisse: Mit Hilfe des Verhaltnisses von Zitrat/(Cholin + Kreatin) konnten benigne Hyperplasien der Prostata von Karzinomen spektroskopisch unterschieden werden. Die Abgrenzung prostatisch intraepithelialer Neoplasien (PIN, Grad III) von Prostatakarzinomen gelang nicht. Mit der verfugbaren raumlichen Auflosung von 1 cm3 konnte der Tumordifferenzierungsgrad mittels Zitrat/(Cholin + Kreatin) nicht vorhergesagt werden. Schlussfolgerung: Die modifizierte 1H-2D-CSI-Sequenz eignet sich aufgrund der dadurch verbesserten Spektrenqualitat zur Erkennung von Prostatakarzinomen. Eine Tumordifferenzierung war mit der verwendeten Auflosung nicht moglich. Purpose: Methodological optimization of a 1H MR spectroscopic imaging sequence (1H-2D-CSI) and evaluation of its potential to diagnose prostate cancer as validated by histopathological maps. Methods: The prostates of 18 patients were evaluated by 1H-MR-CSI (voxel dimension: 1 cm3) at 1,5 Tesla. This sequence was additionally combined with a frequency selective fat suppression. Results: It was possible to distinguish prostate carcinoma from prostate hyperplasia spectroscopically by the ratio of citrate/(choline + creatine). Differentiation of high-grade prostatic intraepithelial neoplasia (PIN, high-grade) from prostate carcinoma was not unambiguously possible. Prediction of tumor differentiation was not possible by the ratio of citrate/(choline + creatine) by our maximum spatial resolution of 1 cm3. Conclusion: 1H-2D-CSI is suitable for tumor detection. Tumor differentiation was not possible with the spatial resolution used.

Two previously proposed training sequence optimization techniques for channel estimation are compared. One method is based on a frequency-domain (FD) based channel estimation method and the other is based on a time-domain (TD) channel estimation technique. The FD method produces a lower complexity search strategy, but does not always result in the optimal training sequences in terms of the mean-squared channel estimation error. A proof of the superiority of the TD method over the FD method is presented. Based on the proof, an alternative search criterion is proposed, which, in general, provides equivalent or better performance than the FD method while still enjoying the low search complexity.

We demonstrate the feasibility of a new versatile hybrid imaging concept, the combined acquisition technique (CAT), for cardiac imaging. The cardiac CAT approach, which combines new methodology with existing technology, essentially integrates fast low-angle shot (FLASH) and echoplanar imaging (EPI) modules in a sequential fashion, whereby each acquisition module is employed with independently optimized imaging parameters. One important CAT sequence optimization feature is the ability to use different bandwidths for different acquisition modules. Twelve healthy subjects were imaged using three cardiac CAT acquisition strategies: a) CAT was used to reduce breath-hold duration times while maintaining constant spatial resolution; b) CAT was used to increase spatial resolution in a given breath-hold time; and c) single-heart beat CAT imaging was performed. The results obtained demonstrate the feasibility of cardiac imaging using the CAT approach and the potential of this technique to accelerate the imaging process with almost conserved image quality.