Marcushodges6582

The last two decades have seen vigorous activity in synthetic biology research and ever-increasing applications of its technologies. However, pedagogical research pertaining to teaching synthetic biology is scarce, especially when compared to other science and engineering disciplines. Within Canada there are only three universities that offer synthetic biology programs; two of which are at the undergraduate level. Rather than take place in formal academic settings, many Canadian undergraduate students are introduced to synthetic biology through participation in the annual International Genetically Engineered Machine (iGEM) competition. Although the iGEM competition has had a transformative impact on synthetic biology training in other nations, the impact in Canada has been relatively modest. Consequently, the iGEM competition is still a major setting for synthetic biology education in Canada. To promote further development of synthetic biology education, we surveyed undergraduate students from the Canadian iGEM design teams of 2019. We extracted insights from these data using qualitative analysis to provide recommendations for best teaching practices in synthetic biology undergraduate education, which we describe through our proposed Framework for Transdisciplinary Synthetic Biology Education (FTSBE).Haemophilus influenzae colonizes the respiratory tract and is associated with life-threatening invasive infections. The recent rise in its global prevalence, even in the presence of multiple vaccines, indicate an urgent need for developing cross-strain effective vaccine strategies. Our work focused on identifying the universally conserved antigenic regions of H. influenzae that can be used for developing new vaccines. A variety of bioinformatics tools were applied for the comprehensive geno-proteomic analysis of H. influenzae type "a" strain, as reference serotype, through which subcellular localization, essentiality, virulence, and non-host homology were determined. B and T-Cell epitope mapping of 3D protein structures were performed. Thereafter, molecular docking with HLA DRB1*0101 and comparative genome analysis established the candidature of identified regions. Based on the established vaccinomics criteria, five target proteins were predicted as novel vaccine candidates. Among these, 9 epitopic regions were identified that could regulate the lymphocyte activity through strong protein-protein interactions. Comparative genomic analysis exhibited that the identified regions were highly conserved among the different strains of H. influenzae. Based on multiple immunogenic factors, the five prioritized proteins and their predicted epitopes were identified as the ideal common putative vaccine candidate against typeable strains.The total synthesis of leiodermatolide A was accomplished in 13 steps (LLS). Transfer hydrogenative variants of three carbonyl additions that traditionally rely on premetalated reagents (allylation, crotylation, and propargylation) are deployed together in one total synthesis.Although engineered microbial production of natural compounds provides a promising alternative method to plant production and extraction, the process can be inefficient and ineffective in terms of time and cost. To render microbial systems profitable and viable, the process must be optimized to produce as much product as possible. To this end, this work illustrates the construction of a new probabilistic computational model to simulate the microbial production of a well-known cardioprotective molecule, resveratrol, and the implementation of the model to enhance the yield of the product in Escherichia coli. This model identified stilbene synthase as the limiting enzyme and informed the effects on changes in concentration and source of this enzyme. These parameters, when employed in a laboratory system, were able to improve the titer from 62.472 mg/L to 172.799 mg/L, demonstrating the model's ability to produce a useful simulation of a dynamic microbial resveratrol production system.Copolymerization of olefin with carbon monoxide has received considerable interest from both academia and industry, and the introduction of polar carbonyl group renders the resultant polyketones with excellent mechanical strength, crystallinity, photodegradability, hydrophilicity, surface, and barrier properties. However, most of the reported polyketones are difficult to be processed because of limited solubility in common solvents and high melting temperature (Tm ∼ 260 °C) resulting from the strictly alternative structure. Nonalternating copolymerization of ethylene with CO is a very promising method to circumvent the problem of processability of traditional perfectly alternating polyketone. In the contribution, the palladium coordinated diphosphazane monoxide substituted by strong electron-donating groups is discovered to be highly reactive for producing nonalternating polyketones, and up to 24.2% extra ethylene incorporation has lowered Tm values to 147 and 165 °C and further improved thermal stability (Td ∼ 339 °C) of the resultant materials. Our data demonstrates that cationic palladium complexes can also exhibit excellent reactivity and an unprecedented nonalternating degree in this copolymerization.A layered semiconductor, SrTiN2, has an interesting crystal structure as a two-dimensional (2D) electron system embedded in a three-dimensional bulk periodic structure because it has alternate stacking of a SrN blocking layer and a TiN conduction layer, in which the Ti 3dxy orbital forms the conduction band minimum (CBM) similar to the SrTiO3-based thin-film heterostructure. However, SrTiN2 has been reported to exhibit nearly degenerate conduction, but we reported that it would be due to the easy formation of nitrogen vacancies and oxygen impurities from air. In this paper, we extend the materials to family compounds, alkaline earth (AE) ion-substituted, AETiN2 (AE = Ca, Sr, and Ba), and investigated how we can suppress the defect formation by (hybrid) density functional theory calculations. All AETiN2 compounds possess thermodynamic stability in the wide nitrogen (N) chemical potential window. Especially, CaTiN2 is the most stable even against N-poor conditions. Unintentional carrier generation occurs due to the nitrogen vacancies (VN), oxygen substitution (ON), and hydrogen anion substitution (HN) at the nitrogen sites. find more The VN and HN impurities can be suppressed under N-moderate and N-rich conditions. The ON defect is easily formed in SrTiN2 and also in BaTiN2 under N-rich conditions, but its formation can be suppressed in CaTiN2. Present results suggest that high-purity CaTiN2 can be obtained under wider N chemical conditions, which would lead to the realization of the novel functional properties originating from Ti 3dxy 2D bands embedded in the bulk crystal structure.Organic photocatalysts (PCs) are gaining popularity in applications of photoredox catalysis, but few studies have explored their modus operandi. We report a detailed mechanistic investigation of the electron transfer activation step of organocatalyzed atom transfer radical polymerization (O-ATRP) involving electronically excited organic PCs and a radical initiator, methyl 2-bromopropionate (MBP). This study compares nine N-aryl modified PCs possessing dihydrophenazine, phenoxazine, or phenothiazine core chromophores. Transient electronic and vibrational absorption spectroscopies over subpicosecond to nanosecond and microsecond time intervals, respectively, track spectroscopic signatures of both the reactants and products of photoinduced electron transfer in N,N-dimethylformamide, dichloromethane, and toluene solutions. The rate coefficients for electron transfer exhibit a range of values up to ∼1010 M-1 s-1 influenced systematically by the PC structures. These rate coefficients are an order of magnitude smaller for catalysts with charge transfer character in their first excited singlet (S1) or triplet (T1) states than for photocatalysts with locally excited character. The latter species show nearly diffusion-limited rate coefficients for the electron transfer to MBP. The derived kinetic parameters are used to model the contributions to electron transfer from the S1 state of each PC for different concentrations of MBP. Comparisons of singlet and triplet reactivity for one of the phenoxazine PCs reveal that the rate coefficient kET(T1) = (2.7 ± 0.3) × 107 M-1 s-1 for electron transfer from the T1 state is 2 orders of magnitude lower than that from the S1 state, kET(S1) = (2.6 ± 0.4) × 109 M-1 s-1. The trends in bimolecular electron transfer rate coefficients are accounted for using a modified Marcus theory for dissociative electron transfer.A novel cell-free biosynthesis system based on a mixture of chassis cell extracts and purified Spy-cyclized enzymes (CFBS-mixture) was developed. As a demonstration, the CFBS-mixture was applied to chlorogenic acid (CGA) biosynthesis. The mix-and-match and Plackett-Burman experiments demonstrated that Lonicera japonica hydroxycinnamate-CoA quinate transferase and p-hydroxyphenylacetate 3-hydroxylase were the key enzymes for the production of CGA. After optimization of the concentrations of the biosynthetic enzymes in the CFBS-mixture reaction using the Plackett-Burman experimental design and the path of the steepest ascent, 711.26 ± 15.63 mg/L CGA was produced after 16 h, which is 71.1-fold the yield obtained using the conventional crude extract-based CFBS and 9.1-fold the reported yield obtained using the living cells. Based on the CFBS-mixture results, the production of CGA was further enhanced in engineered Escherichia coli. The CFBS-mixture strategy is highly effective and will be useful for high-level CFBS of natural products.The development of vaccines against severe acute respiratory syndrome coronavirus 2, which features high mortality and morbidity rates, has progressed at an unprecedented rate, and vaccines are currently in use worldwide. Thrombotic events after vaccination are accompanied by thrombocytopenia, and this issue was recently termed vaccine-induced immune thrombotic thrombocytopenia. This manuscript describes recently published guidelines and other related issues and demonstrates characteristic cases.Palisading encapsulated neuroma is a rare, benign, cutaneous nerve sheath tumor. It usually occurs as an asymptomatic solitary skin-colored papule and commonly affects the nose and cheeks. Sometimes, it involves other sites, including the shoulder, upper arm, and trunk, but rarely involves the oral mucosa, including that of the lip. In our case, a 63-year-old female patient complained of a pinkish rubbery nodule on her lower lip. Histopathologic examination demonstrated a well-circumscribed nodule encapsulated by connective tissue stroma in the dermis. The nodule consisted of palisading spindle-shaped tumor cells with wavy and basophilic nuclei. The cells were arranged in streaming fascicles with multiple clefts and were strongly positive for S-100 proteins. To our knowledge, only three cases of palisading encapsulated neuroma on the lower lip have been reported in the Korean literature. Herein, we report a rare case of an oral palisaded encapsulated neuroma.