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Efficient Manner (efficient + manner)
Selected AbstractsCross-institutional assessment: Development and implementation of the On-line Student Survey SystemCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 2 2002Raymond Hoare Abstract As ABET has increased the need for routine student assessments, engineering faculty are faced with the problem of doing this in an efficient manner that minimizes the time required to conduct, tabulate, and analyze the requisite surveys. To meet this need, researchers at the University of Pittsburgh have developed the On-line Student Survey System (OS3) to facilitate EC 2000 assessment and cross-institutional benchmarking. OS3 allows multiple engineering schools to conduct customized, routine program evaluations using Web-based surveys specifically designed to meet EC 2000 objectives. Since its inception, seven engineering schools have adopted OS3. This article provides an overview of the system, a des-cription of its survey instruments, and an evaluation of the system. © 2002 Wiley Periodicals, Inc. Comput Appl Eng Educ 10: 88,97, 2002; Published online in Wiley InterScience (www.interscience.wiley.com.); DOI 10.1002/cae.10013 [source] The Neutralizer: a self-configurable failure detector for minimizing distributed storage maintenance costCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 2 2009Zhi Yang Abstract To achieve high data availability or reliability in an efficient manner, distributed storage systems must detect whether an observed node failure is permanent or transient, and if necessary, generate replicas to restore the desired level of replication. Given the unpredictability of network dynamics, however, distinguishing permanent and transient failures is extremely difficult. Though timeout-based detectors can be used to avoid mistaking transient failures as permanent failures, it is unknown how the timeout values should be selected to achieve a better tradeoff between detection latency and accuracy. In this paper, we address this fundamental tradeoff from several perspectives. First, we explore the impact of different timeout values on maintenance cost by examining the probability of their false positives and false negatives. Second, we propose a self-configurable failure detector called the Neutralizer based on the idea of counteracting false positives with false negatives. The Neutralizer could enable the system to maintain a desired replication level on average with the least amount of bandwidth. We conduct extensive simulations using real trace data from a widely deployed peer-to-peer system and synthetic traces based on PlanetLab and Microsoft PCs, showing a significant reduction in aggregate bandwidth usage after applying the Neutralizer (especially in an environment with a low average node availability). Overall, we demonstrate that the Neutralizer closely approximates the performance of a perfect ,oracle' detector in many cases. Copyright © 2008 John Wiley & Sons, Ltd. [source] The contributions of microtubule stability and dynamic instability to adenovirus nuclear localization efficiencyCYTOSKELETON, Issue 9 2007James C. Warren Abstract Adenoviruses (Ads) utilize host cell microtubules to traverse the intracellular space and reach the nucleus in a highly efficient manner. Previous studies have shown that Ad infection promotes the formation of stable, posttranslationally modified microtubules by a RhoA-dependent mechanism. Ad infection also shifts key parameters of microtubule dynamic instability by a Rac1-dependent mechanism, resulting in microtubules with lower catastrophe frequencies, persistent growth phases, and a bias toward net growth compared to microtubules in uninfected cells. Until now it was unclear whether changes in RhoGTPase activity or microtubule dynamics had a direct impact on the efficiency of Ad microtubule-dependent nuclear localization. Here we have performed synchronous Ad infections and utilized confocal microscopy to analyze the individual contributions of RhoA activation, Rac1 activation, microtubule stability, dynamic behavior, and posttranslational modifications on Ad nuclear localization efficiency (NLE). We found that drug-induced suppression of microtubule dynamics impaired Ad NLE by disrupting the radial organization of the microtubule array. When the microtubule array was maintained, the suppression or enhancement of microtubule turnover did not significantly affect Ad NLE. Furthermore, RhoA activation or the formation of acetylated microtubules did not enhance Ad NLE. In contrast, active Rac1 was required for efficient Ad nuclear localization. Because Rac1 mediates persistent growth of microtubules to the lamellar regions of cells, we propose that Ad-induced activation of Rac1 enhances the ability of microtubules to "search and capture" incoming virus particles. Cell Motil. Cytoskeleton 2007. © 2007 Wiley-Liss, Inc. [source] Guidelines for the management of traumatic dental injuries.DENTAL TRAUMATOLOGY, Issue 4 2007Abstract ,, Trauma to the primary dentition present special problems and the management is often different as compared with permanent teeth. An appropriate emergency treatment plan is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases in which the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence based on literature research and professional opinion. In this third article out of three, the IADT Guidelines for the management of traumatic injuries in the primary dentition, are presented. [source] Guidelines for the management of traumatic dental injuries.DENTAL TRAUMATOLOGY, Issue 3 2007Abstract,,, Avulsion of permanent teeth is the most serious of all dental injuries. The prognosis depends on the measures taken at the place of accident or the time immediately after the avulsion. Replantation is the treatment of choice, but cannot always be carried out immediately. An appropriate emergency management and treatment plan is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases in which the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence based on literature research and professional opinion. In this second article of three, the IADT Guidelines for management of avulsed permanent teeth are presented. [source] Guidelines for the management of traumatic dental injuries.DENTAL TRAUMATOLOGY, Issue 2 2007Abstract,,, Crown fractures and luxations occur most frequently of all dental injuries. An appropriate treatment plan after an injury is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence, based on literature research and professional opinion. In this first article of three, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented. [source] Minimization of socioeconomic disruption for displaced populations following disastersDISASTERS, Issue 3 2010Omar El-Anwar In the aftermath of catastrophic natural disasters such as hurricanes, tsunamis and earthquakes, emergency management agencies come under intense pressure to provide temporary housing to address the large-scale displacement of the vulnerable population. Temporary housing is essential to enable displaced families to reestablish their normal daily activities until permanent housing solutions can be provided. Temporary housing decisions, however, have often been criticized for their failure to fulfil the socioeconomic needs of the displaced families within acceptable budgets. This paper presents the development of (1) socioeconomic disruption metrics that are capable of quantifying the socioeconomic impacts of temporary housing decisions on displaced populations; and (2) a robust multi-objective optimization model for temporary housing that is capable of simultaneously minimizing socioeconomic disruptions and public expenditures in an effective and efficient manner. A large-scale application example is optimized to illustrate the use of the model and demonstrate its capabilities ingenerating optimal plans for realistic temporary housing problems. [source] Rapid plant diversity assessment using a pixel nested plot design: A case study in Beaver Meadows, Rocky Mountain National Park, Colorado, USADIVERSITY AND DISTRIBUTIONS, Issue 4 2007Mohammed A. Kalkhan ABSTRACT Geospatial statistical modelling and thematic maps have recently emerged as effective tools for the management of natural areas at the landscape scale. Traditional methods for the collection of field data pertaining to questions of landscape were developed without consideration for the parameters of these applications. We introduce an alternative field sampling design based on smaller unbiased random plot and subplot locations called the pixel nested plot (PNP). We demonstrate the applicability of the PNP design of 15 m × 15 m to assess patterns of plant diversity and species richness across the landscape at Rocky Mountain National Park (RMNP), Colorado, USA in a time (cost)-efficient manner for field data collection. Our results produced comparable results to a previous study in the Beaver Meadow study (BMS) area within RMNP, where there was a demonstrated focus of plant diversity. Our study used the smaller PNP sampling design for field data collection which could be linked to geospatial information data and could be used for landscape-scale analyses and assessment applications. In 2003, we established 61 PNP in the eastern region of RMNP. We present a comparison between this approach using a sub-sample of 19 PNP from this data set and 20 of Modified Whittaker nested plots (MWNP) of 20 m × 50 m that were collected in the BMS area. The PNP captured 266 unique plant species while the MWNP captured 275 unique species. Based on a comparison of PNP and MWNP in the Beaver Meadows area, RMNP, the PNP required less time and area sampled to achieve a similar number of species sampled. Using the PNP approach for data collection can facilitate the ecological monitoring of these vulnerable areas at the landscape scale in a time- and therefore cost-effective manner. [source] A polymeric master replication technology for mass fabrication of poly(dimethylsiloxane) microfluidic devicesELECTROPHORESIS, Issue 9 2005Hai-Fang Li Abstract A protocol of producing multiple polymeric masters from an original glass master mold has been developed, which enables the production of multiple poly(dimethylsiloxane) (PDMS)-based microfluidic devices in a low-cost and efficient manner. Standard wet-etching techniques were used to fabricate an original glass master with negative features, from which more than 50 polymethylmethacrylate (PMMA) positive replica masters were rapidly created using the thermal printing technique. The time to replicate each PMMA master was as short as 20 min. The PMMA replica masters have excellent structural features and could be used to cast PDMS devices for many times. An integration geometry designed for laser-induced fluorescence (LIF) detection, which contains normal deep microfluidic channels and a much deeper optical fiber channel, was successfully transferred into PDMS devices. The positive relief on seven PMMA replica masters is replicated with regard to the negative original glass master, with a depth average variation of 0.89% for 26 ,m deep microfluidic channels and 1.16% for the 90 ,m deep fiber channel. The imprinted positive relief in PMMA from master-to-master is reproducible with relative standard deviations (RSDs) of 1.06% for the maximum width and 0.46% for depth in terms of the separation channel. The PDMS devices fabricated from the PMMA replica masters were characterized and applied to the separation of a fluorescein isothiocyanate (FITC)-labeled epinephrine sample. [source] Utility of the Gyrus open forceps in hepatic parenchymal transectionHPB, Issue 3 2009Matthew R. Porembka Abstract Objective:, This study aimed to evaluate if the Gyrus open forceps is a safe and efficient tool for hepatic parenchymal transection. Background:, Blood loss during hepatic transection remains a significant risk factor for morbidity and mortality associated with liver surgery. Various electrosurgical devices have been engineered to reduce blood loss. The Gyrus open forceps is a bipolar cautery device which has recently been introduced into hepatic surgery. Methods:, We conducted a single-institution, retrospective review of all liver resections performed from November 2005 through November 2007. Patients undergoing resection of at least two liver segments where the Gyrus was the primary method of transection were included. Patient charts were reviewed; clinicopathological data were collected. Results:, Of the 215 open liver resections performed during the study period, 47 patients met the inclusion criteria. Mean patient age was 61 years; 34% were female. The majority required resection for malignant disease (94%); frequent indications included colorectal metastasis (66%), hepatocellular carcinoma (6%) and cholangiocarcinoma (4%). Right hemihepatectomy (49%), left hemihepatectomy (13%) and right trisectionectomy (13%) were the most frequently performed procedures. A total of 26 patients (55%) underwent a major ancillary procedure concurrently. There were no operative mortalities. Median operative time was 220 min (range 97,398 min). Inflow occlusion was required in nine patients (19%) for a median time of 12 min (range 3,30 min). Median total estimated blood loss was 400 ml (range 10,2000 ml) and 10 patients (21%) required perioperative transfusion. All patients had macroscopically negative margins. Median length of stay was 8 days. Two patients (4%) had clinically significant bile leak. The 30-day postoperative mortality was zero. Conclusions:, Use of the Gyrus open forceps appears to be a safe and efficient manner of hepatic parenchymal transection which allows rapid transection with acceptable blood loss, a low rate of perioperative transfusion, and minimal postoperative bile leak. [source] Optimal use of high-resolution topographic data in flood inundation modelsHYDROLOGICAL PROCESSES, Issue 3 2003P. D. Bates Abstract In this paper we explore the optimum assimilation of high-resolution data into numerical models using the example of topographic data provision for flood inundation simulation. First, we explore problems with current assimilation methods in which numerical grids are generated independent of topography. These include possible loss of significant length scales of topographic information, poor representation of the original surface and data redundancy. These are resolved through the development of a processing chain consisting of: (i) assessment of significant length scales of variation in the input data sets; (ii) determination of significant points within the data set; (iii) translation of these into a conforming model discretization that preserves solution quality for a given numerical solver; and (iv) incorporation of otherwise redundant sub-grid data into the model in a computationally efficient manner. This processing chain is used to develop an optimal finite element discretization for a 12 km reach of the River Stour in Dorset, UK, for which a high-resolution topographic data set derived from airborne laser altimetry (LiDAR) was available. For this reach, three simulations of a 1 in 4 year flood event were conducted: a control simulation with a mesh developed independent of topography, a simulation with a topographically optimum mesh, and a further simulation with the topographically optimum mesh incorporating the sub-grid topographic data within a correction algorithm for dynamic wetting and drying in fixed grid models. The topographically optimum model is shown to represent better the ,raw' topographic data set and that differences between this surface and the control are hydraulically significant. Incorporation of sub-grid topographic data has a less marked impact than getting the explicit hydraulic calculation correct, but still leads to important differences in model behaviour. The paper highlights the need for better validation data capable of discriminating between these competing approaches and begins to indicate what the characteristics of such a data set should be. More generally, the techniques developed here should prove useful for any data set where the resolution exceeds that of the model in which it is to be used. Copyright © 2002 John Wiley & Sons, Ltd. [source] A dynamic key management solution to access hierarchyINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 6 2007Xukai Zou Hierarchical access control (HAC) has been a fundamental problem in computer and network systems. Since Akl and Taylor proposed the first HAC scheme based on number theory in 1983, cryptographic key management techniques for HAC have appeared as a new and promising class of solutions to the HAC problem. Many cryptographic HAC schemes have been proposed in the past two decades. One common feature associated with these schemes is that they basically limited dynamic operations at the node level. In this paper, by introducing the innovative concept of ,access polynomial' and representing a key value as the sum of two polynomials in a finite field, we propose a new key management scheme for dynamic access hierarchy. The newly proposed scheme supports full dynamics at both the node level and user level in a uniform yet efficient manner. Furthermore, the new scheme allows access hierarchy to be a random structure and can be flexibly adapted to many other access models such as ,transfer down' and ,depth-limited transfer'. Copyright © 2007 John Wiley & Sons, Ltd. [source] The Addition Reaction of Samarium Enolates and 2-Haloenolates Derived from Esters, and Amides to Imines.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 20094-Diamino Esters or Amides, Totally Stereoselective Synthesis of Enantiopure Abstract The addition reaction of samarium enolates and 2-haloenolates derived from esters and amides to imines takes place in an efficient manner. A novel protocol to perform the addition reaction of samarium enolates derived from esters or amides to chiral 2-aminoimines, with total stereoselectivity and without racemization, is also reported. The use of samarium enolates in place of other classic metallic enolates (lithium, magnesium, etc.) could be a valuable alternative to obtain enantiopure 3,4-diamino esters or amides, when enolates of low basicity are necessary. [source] A Thermostable Aldolase for the Synthesis of 3-Deoxy-2-ulosonic AcidsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2007Henry Abstract A stereochemically promiscuous 2-keto-3-deoxygluconate aldolase has been used as an efficient biocatalyst to catalyse the aldol reaction of pyruvate with C3 - and C4 -aldoses to afford syn - and anti -3-deoxy-2-ulosonic acids in poor to good de. A continuous flow bioreactor containing immobilised aldolase has been developed that enables gram quantities of C6 - and C7 -3-deoxyhept-2-ulosonic acids to be produced in an efficient manner. [source] To sample or eradicate?JOURNAL OF APPLIED ECOLOGY, Issue 4 2008A cost minimization model for monitoring, managing an invasive species Summary 1Considerable effort is expended by national and local governments to exclude alien species via detection and eradication of invading populations, but these efforts are not necessarily designed in the most economically or biologically efficient manner. 2Using the invasion of the European strain of the gypsy moth Lymantria dispar into the USA as a case study, we develop an analytical model to determine the optimal trap density for detecting isolated infestations. Most models focus on monitoring or eradication costs only; our model considers the costs of both detection and eradication when determining the best monitoring strategy. 3The model assumes that all isolated populations must be located and eradicated by the conclusion of a programme. For programmes lasting longer than 1 year, it is more worthwhile to proactively monitor and manage rather than to wait until the programme is over. 4For a management programme of a given length, optimal trap density is most influenced by the growth rate of the infestation. Optimal trap densities are lowest for infestations with very low growth rates (because they remain small and therefore are less expensive to eradicate) or very high growth rates (because they are easier to detect), and highest for infestations with moderate growth rates (because they are neither inexpensive to eradicate nor easy to detect). 5Our model is useful in setting a baseline level of monitoring for isolated incidents of gypsy moth invasion. Analysis of data in two US states show that actual trap densities are far higher than the optimal densities from the model. The difference suggests risk aversion may play a role in real systems. 6Synthesis and applications. Our model suggests that we can improve the efficiency of detection and eradication programmes for isolated infestations by optimizing detection effort relative to infestation growth rates and management programme duration. It also clearly demonstrates the importance of balancing the costs and benefits of both detection and eradication when developing invasive species monitoring programmes. [source] Use of a PGU1 recombinant Saccharomyces cerevisiae strain in oenological fermentationsJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2000M. Vilanova Aim: The aim of this work was the construction of an oenological Saccharomyces cerevisiae strain able to overexpress the PGU1 gene in order to be used in trial fermentations. Methods and Results: The recombinant strain is able to secrete an active endopolygalacturonase into the medium leaving its fermentation ability essentially unchanged. Wines obtained with the recombinant strain and the untransformed counterpart did not differ in their physicochemical parameters or major sensory characteristics. The time needed for wine filtration was dramatically reduced in wines elaborated with the PGU1 recombinant strain, and was comparable to the filtration time shown by wines elaborated from must supplemented with fungal pectolytic enzymes. Conclusions: The oenological strain constructed in this work secretes an endopolygalacturonase into the wine in an efficient manner, resulting in an improvement in wine filtration but preserving wine typicality and keeping the methanol levels unchanged. Significance and Impact of the Study: The PGU1 recombinant strains could be used in oenological fermentations as an alternative to commercial pectolytic enzymes of fungal origin. [source] Effect of Branch Length on 13C NMR Relaxation Properties in Molten Poly[ethylene- co -(, -olefin)] Model SystemsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 19-20 2007Matthew Parkinson Abstract The potential of branch length discrimination for branches containing six and more carbons via bulk NMR relaxation properties in the melt-state has been explored. A systematic increase in the 13C spin-lattice relaxation time (T) of the terminal branch carbons 1 and 2 was observed when the branch increased from 6 to 16 carbons in length. The measurement of T via inversion recovery at high-field showed the most reliable data. The effects of saturation and NOE were addressed by using recycle delays longer than 5,×,T and the use of the saturation recovery was found to be unsatisfactory. All nuclear relaxation times were determined in a highly time efficient manner using a previously developed melt-state MAS NMR method. [source] Tyrosine polyethylene glycol (PEG)-micelle magnetic resonance contrast agent for the detection of lipid rich areas in atherosclerotic plaqueMAGNETIC RESONANCE IN MEDICINE, Issue 5 2009Anne Beilvert Abstract Vulnerable or high-risk atherosclerotic plaques often exhibit large lipid cores and thin fibrous caps that can lead to deadly vascular events when they rupture. In this study, polyethylene glycol (PEG)-micelles that incorporate a gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) amphiphile were used as an MR contrast agent. In an approach inspired by lipoproteins, the micelles were functionalized with tyrosine residues, an aromatic, lipophilic amino acid, to reach the lipid-rich areas of atherosclerotic plaque in a highly efficient manner. These micelles were applied to apolipoprotein E,/, (ApoE,/,) mice as a model of atherosclerosis. The abdominal aortas of the animals were imaged using T1 -weighted (T1W) high-resolution MRI at 9.4T before and up to 48 h after the administration of the micelles. PEG-micelles modified with 15% tyrosine residues yielded a significant enhancement of the abdominal aortic wall at 6 and 24 h postinjection (pi) as compared to unmodified micelles. Fluorescence microscopy on histological sections of the abdominal aorta showed a correlation between lipid-rich areas and the distribution of the functionalized contrast agent in plaque. Using a simple approach, we demonstrated that lipid-rich areas in atherosclerotic plaque of ApoE,/, mice can be detected by MRI using Gd-DTPA micelles. Magn Reson Med, 2009. © 2009 Wiley-Liss, Inc. [source] Acute-care surgical service: a change in cultureANZ JOURNAL OF SURGERY, Issue 1-2 2009Andrew D. Parasyn The provision of acute surgical care in the public sector is becoming increasingly difficult because of limitation of resources and the unpredictability of access to theatres during the working day. An acute-care surgical service was developed at the Prince of Wales Hospital to provide acute surgery in a more timely and efficient manner. A roster of eight general surgeons provided on-site service from 08.00 to 18.00 hours Monday to Friday and on-call service in after-hours for a 79-week period. An acute-care ward of four beds and an operating theatre were placed under the control of the rostered acute-care surgeon (ACS). At the end of each ACS roster period all patients whose treatment was undefined or incomplete were handed over to the next rostered ACS. Patient data and theatre utilization data were prospectively collected and compared to the preceding 52-week period. Emergency theatre utilization during the day increased from 57 to 69%. There was a 11% reduction in acute-care operating after hours and 26% fewer emergency cases were handled between midnight and 08.00 hours. There was more efficient use of the entire theatre block, suggesting a significant cultural change. Staff satisfaction was high. On-site consultant-driven surgical leadership has provided significant positive change to the provision of acute surgical care in our institution. The paradigm shift in acute surgical care has improved patient and theatre management and stimulated a cultural change of efficiency. [source] Anomalies in the Oversight of Australian AuditorsAUSTRALIAN ACCOUNTING REVIEW, Issue 2 2010Graeme L. Wines This commentary identifies and comments on anomalies in the oversight of Australian auditors and audit firms. Regulatory and professional oversight and inspection of Australian auditors and audit firms arise from a number of sources, highlighting its multi-faceted nature. This makes it impossible to identify a single body with ultimate responsibility for auditor oversight. Three recent Australian reviews commissioned by the Financial Reporting Council, together with an evaluation of the roles of the various regulatory and professional bodies, are used in this commentary as a platform from which to identify a number of significant anomalies in oversight processes. Major anomalies highlighted arise from the overlapping nature of the duties and functions of the various bodies and the variation in oversight across different categories of audit service providers. Policymakers should closely examine the issues raised in the paper if auditor oversight is to be undertaken in an effective and efficient manner. [source] A tightly regulated inducible expression system utilizing the fim inversion recombination switchBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2006Timothy S. Ham Abstract The fim inversion system of Escherichia coli (E. coli) can behave as a unidirectional switch in an efficient manner. We have developed a new expression system for E. coli, comprising the arabinose-inducible fimE gene and the fim invertible DNA segment containing a constitutively active promoter. In this system, the target gene is cloned with the promoter in the OFF orientation, resulting in no transcribed product. When induced by arabinose, the active promoter is switched to the ON orientation via FimE-catalyzed DNA inversion, and the gene is expressed. Our expression system exhibited very tightly controlled basal expression and high induced expression, with simple induction by inexpensive arabinose. These characteristics make our system suitable for large-scale expression or for production of toxic proteins. © 2006 Wiley Periodicals, Inc. [source] Rapid Matrix-Assisted Refolding of Histidine-Tagged ProteinsCHEMBIOCHEM, Issue 5 2009Tetyana Dashivets Abstract Matrix refolded: The formation of inclusion bodies, which are amorphous aggregates of misfolded insoluble protein, during recombinant protein expression, is one of the biggest bottlenecks in protein science. We report a stepwise, rational optimization procedure for refolding of insoluble proteins (see scheme). In comparison to refolding in-solution, this parallelized, matrix-assisted approach allows the refolding of various proteins in a fast and efficient manner. The formation of inclusion bodies (IBs),amorphous aggregates of misfolded insoluble protein,during recombinant protein expression, is still one of the biggest bottlenecks in protein science. We have developed and analyzed a rapid parallel approach for matrix-assisted refolding of recombinant His6 -tagged proteins. Efficiencies of matrix-assisted refolding were screened in a 96-well format. The developed methodology allowed the efficient refolding of five different test proteins, including monomeric and oligomeric proteins. Compared to refolding in-solution, the matrix-assisted refolding strategy proved equal or better for all five proteins tested. Interestingly, specifically oligomeric proteins displayed significantly higher levels of refolding compared to refolding in-solution. Mechanistically, matrix-assisted folding seems to differ from folding in-solution, as the reaction proceeds more rapidly and shows a remarkably different concentration dependence,it allows refolding at up to 1000-fold higher protein concentration than folding in-solution. [source] ChemInform Abstract: Reduction of Polycyclic Aromatic Hydrocarbons Promoted by Cobalt or Manganese Nanoparticles.CHEMINFORM, Issue 43 2010Fabiana Nador Abstract Partial reduction of a variety of polycyclic (het)aromatic hydrocarbons is achieved in a simple and efficient manner. [source] Design, Synthesis, and Biological Evaluation of Artificial Macrosphelides in the Search for New Apoptosis-Inducing AgentsCHEMISTRY - A EUROPEAN JOURNAL, Issue 23 2009Yuji Matsuya Dr. Abstract A drug of two halves: New artificial compounds composed of a macrosphelide core skeleton and an epothilone side chain were designed and synthesized. These compounds were more potent inducers of apoptosis than the parent natural-type macrosphelides. Various artificial macrosphelides were designed and synthesized, including ring-enlarged analogues and epothilone-hybrid compounds. Syntheses were accomplished in an efficient manner by using a ring-closing metathesis (RCM) strategy in a key macrocyclization step. Biological evaluation of these new macrosphelide-based derivatives revealed that several epothilone hybrids, in which a thiazole-containing side chain was incorporated, exhibited potent apoptosis-inducing activity toward human lymphoma cells. These activities were considerably enhanced relative to those of natural macrosphelide compounds. Structure,activity relationship studies revealed that the "ene-dicarbonyl" substructure is apparently essential for bioactivity. [source] | |||||||||||||||||||||||||