532 research outputs found
Alien Registration- Bolduc, Joseph H. (Old Town, Penobscot County)
https://digitalmaine.com/alien_docs/7688/thumbnail.jp
Chemoenzymatic Synthesis of Cryptophycin Anticancer Agents by an Ester Bond-Forming Non-ribosomal Peptide Synthetase Module
Cryptophycins (Crp) are a group of cyanobacterial
depsipeptides with activity against drug-resistant tumors. Although they have been shown to be promising, further efforts are required to return these highly potent compounds to the clinic through a new generation of
analogues with improved medicinal properties. Herein,
we report a chemosynthetic route relying on themultifunctional enzyme CrpD-M2 that incorporates a 2-hydroxy acid moiety (unit D) into Crp analogues. CrpD-M2 is a unique nonribosomal peptide synthetase (NRPS) module comprised of condensation-adenylation-ketoreduction-thiolation (C-A-KR-T) domains. We interrogated A-domain 2-keto and 2-hydroxy acid activation and loading, and KR domain activity in the presence of NADPH and NADH. The
resulting 2-hydroxy acid was elongated with three synthetic
Crp chain elongation intermediate analogues through ester
bond formation catalyzed by CrpD-M2 C domain. Finally, the
enzyme-bound seco-Crp products were macrolactonized by
the Crp thioesterase. Analysis of these sequential steps was
enabled through LC-FTICR-MS of enzyme-bound intermediates
and products. This novel chemoenzymatic synthesis of
Crp involves four sequential catalytic steps leading to the
incorporation of a 2-hydroxy acid moiety in the final chain
elongation intermediate. The presented work constitutes the
first example where a NRPS-embedded KR domain is employed
for assembly of a fully elaborated natural product, and
serves as a proof-of-principle for chemoenzymatic synthesis of new Crp analogues
Usefulness of the ManageMed Screen (MMS) and the Screening for Self-Medication Safety Post Stroke (S5) for Assessing Medication Management Capacity for Clients Post-Stroke
Occupational therapists need to efficiently and accurately screen a client’s medication management capacity, especially for clients post-stroke. Most therapists are not aware of, nor do they utilize specific assessments for, medication management capacity. The purpose of this pilot study was to compare the results of the ManageMed Screen (MMS), the Screening for Self-Medication Safety Post Stroke (S5), and the Montreal Assessment of Cognition (MoCA) on a population of rehabilitation clients post-stroke to determine the usefulness of the medication assessment tools in clinical practice. These screens were designed for use in occupational therapy practice among other healthcare professions: the MMS was validated for the general adult population, the S5 for clients post-stroke, and the MoCA is a cognitive screen used with adult clients with a variety of diagnoses including stroke. The MoCA was used to explore the potential relationship between cognition and medication management capacity. Study participants included five clients post-stroke and three occupational therapists. Clients were screened by the occupational therapists with the MMS, S5, and MoCA, and clinicians also participated in a focus group to assess their perceived usefulness of the screens. Results demonstrated that the MMS score compared to the S5 score was not statistically significant (r=.671, p=.215). There is no established consistency between the MoCA and MMS given these five clients. The MMS score was correlated to the MoCA score and was not found to be significant at a value of .205 with p=.741. The S5 score was also correlated to the MoCA score using SPSS and was found to have a non-significant value of -.287 and p=.640. Additionally, through a focus group, clinicians deemed both the MMS and S5 as useful, but felt the MMS was a more useful screen for their clinical practice with regard to efficient and practical use with clients post-stroke in a rehabilitation setting
Exon-Skipping Oligonucleotides Restore Functional Collagen VI by Correcting a Common COL6A1 Mutation in Ullrich CMD
Collagen VI-related congenital muscular dystrophies (COL6-CMDs) are the second most common form of congenital muscular dystrophy. Currently, there is no effective treatment available. COL6-CMDs are caused by recessive or dominant mutations in one of the three genes encoding for the α chains of collagen type VI (COL6A1, COL6A2, and COL6A3). One of the most common mutations in COL6-CMD patients is a de novo deep intronic c.930+189C > T mutation in COL6A1 gene. This mutation creates a cryptic donor splice site and induces incorporation of a novel in-frame pseudo-exon in the mature transcripts. In this study, we systematically evaluated the splice switching approach using antisense oligonucleotides (ASOs) to correct this mutation. Fifteen ASOs were designed using the RNA-tiling approach to target the misspliced pseudo-exon and its flanking sequences. The efficiency of ASOs was evaluated at RNA, protein, and structural levels in skin fibroblasts established from four patients carrying the c.930+189C > T mutation. We identified two additional lead ASO candidates that efficiently induce pseudo-exon exclusion from the mature transcripts, thus allowing for the restoration of a functional collagen VI microfibrillar matrix. Our findings provide further evidence for ASO exon skipping as a therapeutic approach for COL6-CMD patients carrying this common intronic mutation
Effects of Corruption on Efficiency of the European Airports
The effect of corruption on airport productive efficiency is analyzed using an unbalanced panel data of major European airports from 2003 to 2009. We first compute the residual (or net) variable factor productivity using the multilateral index number method and then apply robust cluster random effects model in order to evaluate the importance of corruption. We find strong evidence that corruption has negative impacts on airport operating efficiency; and the effects depend on the ownership form of the airport. The results suggest that airports under mixed public-private ownership with private majority achieve lower levels of efficiency when located in more corrupt countries. They even operate less efficiently than fully and/or majority government owned airports in high corruption environment. We control for economic regulation, competition level and other airports’ characteristics. Our empirical results survive several robustness checks including different control variables, three alternative corruption measures: International Country Risk Guide (ICRG) corruption index, Corruption Perception Index (CPI) and Control of Corruption Index (CCI). The empirical findings have important policy implications for management and ownership structuring of airports operating in countries that suffer from higher levels of corruption
Expanding networks of RNA virus evolution
In a recent BMC Evolutionary Biology article, Huiquan Liu and colleagues report two new genomes of double-stranded RNA (dsRNA) viruses from fungi and use these as a springboard to perform an extensive phylogenomic analysis of dsRNA viruses. The results support the old scenario of polyphyletic origin of dsRNA viruses from different groups of positive-strand RNA viruses and additionally reveal extensive horizontal gene transfer between diverse viruses consistent with the network-like rather than tree-like mode of viral evolution. Together with the unexpected discoveries of the first putative archaeal RNA virus and a RNA-DNA virus hybrid, this work shows that RNA viral genomics has major surprises to deliver
Taxonomic assignment of uncultivated prokaryotic virus genomes is enabled by gene-sharing networks
© 2019, The Author(s), under exclusive licence to Springer Nature America, Inc. Microbiomes from every environment contain a myriad of uncultivated archaeal and bacterial viruses, but studying these viruses is hampered by the lack of a universal, scalable taxonomic framework. We present vConTACT v.2.0, a network-based application utilizing whole genome gene-sharing profiles for virus taxonomy that integrates distance-based hierarchical clustering and confidence scores for all taxonomic predictions. We report near-identical (96%) replication of existing genus-level viral taxonomy assignments from the International Committee on Taxonomy of Viruses for National Center for Biotechnology Information virus RefSeq. Application of vConTACT v.2.0 to 1,364 previously unclassified viruses deposited in virus RefSeq as reference genomes produced automatic, high-confidence genus assignments for 820 of the 1,364. We applied vConTACT v.2.0 to analyze 15,280 Global Ocean Virome genome fragments and were able to provide taxonomic assignments for 31% of these data, which shows that our algorithm is scalable to very large metagenomic datasets. Our taxonomy tool can be automated and applied to metagenomes from any environment for virus classification
Towards an IT-based Planning Process Alignment: Integrated Route and Location Planning for Small Package Shippers
To increase the efficiency of delivery operations in small package shipping (SPS), numerous optimization models for routeand location planning decisions have been proposed. This operations research view of defining independent problems hastwo major shortcomings: First, most models from literature neglect crucial real-world characteristics, thus making themuseless for small package shippers. Second, business processes for strategic decision making are not well-structured in mostSPS companies and significant cost savings could be generated by an IT-based support infrastructure integrating decisionmaking and planning across the mutually dependent layers of strategic, tactical and operational planning. We present anintegrated planning framework that combines an intelligent data analysis tool, which identifies delivery patterns and changesin customer demand, with location and route planning tools. Our planning approaches extend standard Location Routing andVehicle Routing models by crucial, practically relevant characteristics like the existence of subcontractors on both decisionlevels and the implicit consideration of driver familiarity in route planning
About Attitudes and Perceptions: Finding the Proper Way to Consider Latent Variables in Discrete Choice Models
We provide an in-depth theoretical discussion about the differences between attitudes and perceptions, as well as an empirical exercise to analyze its effects. This discussion is of importance, as the large majority of papers considering attitudinal latent variables, just consider those as attributes affecting directly the utility of a certain alternative while systematic taste variations are rarely taken into account and perceptions are normally completely ignored. The results of our case study show that perceptions may indeed affect the decision making process and that they are able to capture a significant part of the variability that is normally explained by alternative specific constants. In the same line, our results indicate that attitudes may be a reason for systematic taste variations, and that a proper categorization of the latent variables, in accordance with the underlying theory, may outperform the customary assumption of linearity
Electrical behavior of MIS devices based on Si nanoclusters embedded in SiOxNy and SiO2 films
We examined and compared the electrical properties of silica (SiO2) and silicon oxynitride (SiOxNy) layers embedding silicon nanoclusters (Sinc) integrated in metal-insulator-semiconductor (MIS) devices. The technique used for the deposition of such layers is the reactive magnetron sputtering of a pure SiO2 target under a mixture of hydrogen/argon plasma in which nitrogen is incorporated in the case of SiOxNy layer. Al/SiOxNy-Sinc/p-Si and Al/SiO2-Sinc/p-Si devices were fabricated and electrically characterized. Results showed a high rectification ratio (>104) for the SiOxNy-based device and a resistive behavior when nitrogen was not incorporating (SiO2-based device). For rectifier devices, the ideality factor depends on the SiOxNy layer thickness. The conduction mechanisms of both MIS diode structures were studied by analyzing thermal and bias dependences of the carriers transport in relation with the nitrogen content
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