Although chemical methods for the selective derivatization of amino acid (AA) side chains in peptides and proteins are available, selective N-terminal labeling is challenging, especially for glycine, which has no side chain at the α-carbon position. We report here a double activation at glycine's α-methylene group that allows this AA to be differentiated from the other 19 AAs. A condensation reaction of dibenzoylmethane with glycine results in the formation of an imine, and subsequent tautomerization is followed by intramolecular cyclization, leading to the formation of a fluorescent pyrrole ring.
View Article and Find Full Text PDFSemiconductor nanocrystals (NCs) interfaced with molecular ligands that function as charge and energy acceptors are an emerging platform for the design of light-harvesting, photon-upconverting, and photocatalytic materials. However, NC systems explored for these applications often feature high concentrations of bound acceptor ligands, which can lead to ligand-ligand interactions that may alter each system's ability to undergo charge and energy transfer. Here, we demonstrate that aggregation of acceptor ligands impacts the rate of photoinduced NC-to-ligand charge transfer between lead(II) sulfide (PbS) NCs and perylenediimide (PDI) electron acceptors.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
November 2022
Background: Material wear caused by relative micromotion of multi-part orthopaedic implants can impact physiology near the implant site and ultimately lead to revision surgery. Cryogenic Thermal Cycling (CTC) is a process that refines and stabilizes the crystal lattice structure of materials by introducing them to temperature modulation cycles that include extremely low temperatures. This method has been proven to significantly improve the performance and wear life capabilities of mechanical components in an efficient, sterile and non-polluting process.
View Article and Find Full Text PDFMolecular encoding in abiotic sequence-defined polymers (SDPs) has recently emerged as a versatile platform for information and data storage. However, the storage capacity of these sequence-defined polymers remains underwhelming compared to that of the information storing biopolymer DNA. In an effort to increase their information storage capacity, herein we describe the synthesis and simultaneous sequencing of eight sequence-defined 10-mer oligourethanes.
View Article and Find Full Text PDFA peptide sequencing scheme utilizing fluorescence microscopy and Edman degradation to determine the amino acid position in fluorophore-labeled peptides was recently reported, referred to as fluorosequencing. It was observed that multiple fluorophores covalently linked to a peptide scaffold resulted in a decrease in the anticipated fluorescence output and worsened the single-molecule fluorescence analysis. In this study, we report an improvement in the photophysical properties of fluorophore-labeled peptides by incorporating long and flexible (PEG) linkers at the peptide attachment points.
View Article and Find Full Text PDFGrainGenes is the USDA-ARS database and Web resource for wheat, barley, oat, rye, and their relatives. As a community Web hub and database for small grains, GrainGenes strives to provide resources for researchers, students, and plant breeders to improve traits such as quality, yield, and disease resistance. Quantitative trait loci (QTL), genes, and genetic maps for quality attributes in GrainGenes represent the historical approach to mapping genes for groat percentage, test weight, protein, fat, and β-glucan content in oat ( spp.
View Article and Find Full Text PDFProc Inst Mech Eng H
February 2022
In vitro test methods are challenged by the multi-factorial nature of head-neck taper connection tribocorrosion due to the consequences of simplification. Incorrect study design and misinterpretation of results has led to contradictory findings regarding important factors affecting head-neck taper tribocorrosion. This review seeks to highlight important considerations when developing in vitro test methods, to help researchers strengthen their study design and analyze the implications of others' design decisions.
View Article and Find Full Text PDFSemiconductor nanocrystals (NCs) have emerged as promising photocatalysts. However, NCs are often functionalized with complex ligand shells that contain not only charge acceptors but also other "spectator ligands" that control NC solubility and affinity for target reactants. Here, we show that spectator ligands are not passive observers of photoinduced charge transfer but rather play an active role in this process.
View Article and Find Full Text PDFNeuroendocrine neoplasms are uncommon in the cervix with almost all representing neuroendocrine carcinomas (NECs), either small cell or large cell type. Cervical low-grade neuroendocrine tumors (NETs) are extremely rare with few recent reports using contemporary modern diagnostic criteria. We report 3 cases of cervical NET in patients aged 32 to 57 yr and undertake a review of the literature.
View Article and Find Full Text PDFBackground: Global surgery (GS) training pathways in residency are unclear and vary by specialty and program. Furthermore, information on these pathways is not always accessible. To address this gap, we produced a collection of open-access webinars for senior medical students focused on identifying GS training pathways during residency.
View Article and Find Full Text PDFAims: This study investigates head-neck taper corrosion with varying head size in a novel hip simulator instrumented to measure corrosion related electrical activity under torsional loads.
Methods: In all, six 28 mm and six 36 mm titanium stem-cobalt chrome head pairs with polyethylene sockets were tested in a novel instrumented hip simulator. Samples were tested using simulated gait data with incremental increasing loads to determine corrosion onset load and electrochemical activity.
Background: Pembrolizumab is a humanized monoclonal antibody that is used to treat a variety of cancers. It exerts its mechanism of action by blocking the programmed death receptor-1 (PD-1). Toxicity concerns include immune-related toxicities, including colitis, hepatitis, pneumonitis, nephritis, endocrine toxicities and more rarely, myocarditis and other organ system toxicities.
View Article and Find Full Text PDFIntroduction: Early detection of melanoma skin cancer improves survival rates. Training family physicians in dermoscopy with the triage amalgamated dermoscopic algorithm (TADA) has high sensitivity and specificity for identifying malignant skin neoplasms. In this study we evaluated the effectiveness of TADA training among medical students, compared with practicing clinicians.
View Article and Find Full Text PDFBackground: In addition to systemic gender disparities, women in surgery encounter interpersonal microaggressions. The objective of this study is to describe the most common forms of microaggressions reported by women in surgery.
Methods: We conducted a scoping review using PubMed/MEDLINE, Ovid, and Web of Science to describe the international, indexed English-language literature on gender-based microaggressions experienced by female surgeons, surgical trainees, and medical students in surgery.
There is growing interest in creating solids that are responsive to various stimuli. Herein we report the first molecular-level mechanistic picture of the thermochromic polymorphic transition in a series of MAN-NI dyad crystals that turn from orange to yellow upon heating with minimal changes to the microscopic morphology following the transition. Detailed structural analyses revealed that the dyads assemble to create an alternating bilayer type structure, with horizontal alternating alkyl and stacked aromatic layers in both the orange and yellow forms.
View Article and Find Full Text PDFThe genus Avena (oats) contains diploid, tetraploid and hexaploid species that evolved through hybridization and polyploidization. Four genome types (named A through D) are generally recognized. We used GBS markers to construct linkage maps of A genome diploid (Avena strigosa x A.
View Article and Find Full Text PDFBackground: Periprosthetic femur fractures are a well-documented complication following direct anterior uncemented total hip arthroplasty. The purpose of this study is to compare the prevalence of postoperative periprosthetic femur fractures between 2 different femoral component designs used in direct anterior total hip arthroplasty.
Methods: Beginning in February 2015, a single fellowship-trained adult reconstruction surgeon performed 361 consecutive direct anterior total hip replacements using a flat, single-taper, wedged femoral implant.
A set of four experiments was conducted to develop methods for screening oat tolerance to salt and alkali and the following results were obtained. (1) In experiment 1, 68.5 mmol L salt and 22.
View Article and Find Full Text PDFThe controlled preparation of higher order oligopyrrolic species holds broad utility across the chemical and material sciences. Here, we describe the gram-scale synthesis of a bench-stable 5,5″-unsubstituted terpyrrole in excellent yield via a tandem Suzuki cross-coupling with in situ deprotection. The solution and solid-state stability as well as UV-vis, fluorescence, and single crystal X-ray diffraction structure are also detailed.
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