Smaller Gold Nanoparticles Release DNA More Efficiently During fs Laser Pulsed Optical Heating.

This work investigates the effect of plasmonic gold nanoparticle (AuNP) size on the rate of thermal release of single-stranded oligonucleotides under femtosecond (fs)-pulsed laser irradiation sources. Contrary to the theoretical predictions that larger AuNPs (50-60 nm diameter) would produce the most solution heating and fastest DNA release, it is found that smaller AuNP diameters (25 nm) lead to faster dsDNA denaturation rates. Controlling for the pulse energy fluence, AuNP concentration, DNA loading density, and the distance from the AuNP surface finds the same result. These results imply that the solution temperature increases around the AuNP during fs laser pulse optical heating may not be the only significant influence on dsDNA denaturation, suggesting that direct energy transfer from the AuNP to the DNA (phonon-phonon coupling), which is increased as AuNPs decrease in size, may play a significant role.

Investigating the dissipation of heat and quantum information from DNA-scaffolded chromophore networks.

Scaffolded molecular networks are important building blocks in biological pigment-protein complexes, and DNA nanotechnology allows analogous systems to be designed and synthesized. System-environment interactions in these systems are responsible for important processes, such as the dissipation of heat and quantum information. This study investigates the role of nanoscale molecular parameters in tuning these vibronic system-environment dynamics. Here, genetic algorithm methods are used to obtain nanoscale parameters for a DNA-scaffolded chromophore network based on comparisons between its calculated and measured optical spectra. These parameters include the positions, orientations, and energy level characteristics within the network. This information is then used to compute the dynamics, including the vibronic population dynamics and system-environment heat currents, using the hierarchical equations of motion. The dissipation of quantum information is identified by the system's transient change in entropy, which is proportional to the heat currents according to the second law of thermodynamics. These results indicate that the dissipation of quantum information is highly dependent on the particular nanoscale characteristics of the molecular network, which is a necessary first step before gleaning the systematic optimization rules. Subsequently, the I-concurrence dynamics are calculated to understand the evolution of the vibronic system's quantum entanglement, which are found to be long-lived compared to these system-bath dissipation processes.

Pursuing excitonic energy transfer with programmable DNA-based optical breadboards.

DNA nanotechnology has now enabled the self-assembly of almost any prescribed 3-dimensional nanoscale structure in large numbers and with high fidelity. These structures are also amenable to site-specific modification with a variety of small molecules ranging from drugs to reporter dyes. Beyond obvious application in biotechnology, such DNA structures are being pursued as programmable nanoscale optical breadboards where multiple different/identical fluorophores can be positioned with sub-nanometer resolution in a manner designed to allow them to engage in multistep excitonic energy-transfer (ET) via Förster resonance energy transfer (FRET) or other related processes. Not only is the ability to create such complex optical structures unique, more importantly, the ability to rapidly redesign and prototype almost all structural and optical analogues in a massively parallel format allows for deep insight into the underlying photophysical processes. Dynamic DNA structures further provide the unparalleled capability to reconfigure a DNA scaffold on the fly in situ and thus switch between ET pathways within a given assembly, actively change its properties, and even repeatedly toggle between two states such as on/off. Here, we review progress in developing these composite materials for potential applications that include artificial light harvesting, smart sensors, nanoactuators, optical barcoding, bioprobes, cryptography, computing, charge conversion, and theranostics to even new forms of optical data storage. Along with an introduction into the DNA scaffolding itself, the diverse fluorophores utilized in these structures, their incorporation chemistry, and the photophysical processes they are designed to exploit, we highlight the evolution of DNA architectures implemented in the pursuit of increased transfer efficiency and the key lessons about ET learned from each iteration. We also focus on recent and growing efforts to exploit DNA as a scaffold for assembling molecular dye aggregates that host delocalized excitons as a test bed for creating excitonic circuits and accessing other quantum-like optical phenomena. We conclude with an outlook on what is still required to transition these materials from a research pursuit to application specific prototypes and beyond.

Determining interchromophore effects for energy transport in molecular networks using machine-learning algorithms.

Nature uses chromophore networks, with highly optimized structural and energetic characteristics, to perform important chemical functions. Due to its modularity, predictable aggregation characteristics, and established synthetic protocols, structural DNA nanotechnology is a promising medium for arranging chromophore networks with analogous structural and energetic controls. However, this high level of control creates a greater need to know how to optimize the systems precisely. This study uses the system's modularity to produce variations of a coupled 14-Site chromophore network. It uses machine-learning algorithms and spectroscopy measurements to reveal the energy-transport roles of these Sites, paying particular attention to the cooperative and inhibitive effects they impose on each other for transport across the network. The physical significance of these patterns is contextualized, using molecular dynamics simulations and energy-transport modeling. This analysis yields insights about how energy transfers across the Donor-Relay and Relay-Acceptor interfaces, as well as the energy-transport pathways through the homogeneous Relay segment. Overall, this report establishes an approach that uses machine-learning methods to understand, in fine detail, the role that each Site plays in an optoelectronic molecular network.

DNA sequencing in the classroom: complete genome sequence of two earwig (Dermaptera; Insecta) species.

BACKGROUND: Despite representing the largest fraction of animal life, the number of insect species whose genome has been sequenced is barely in the hundreds. The order Dermaptera (the earwigs) suffers from a lack of genomic information despite its unique position as one of the basally derived insect groups and its importance in agroecosystems. As part of a national educational and outreach program in genomics, a plan was formulated to engage the participation of high school students in a genome sequencing project. Students from twelve schools across Chile were instructed to capture earwig specimens in their geographical area, to identify them and to provide material for genome sequencing to be carried out by themselves in their schools. RESULTS: The school students collected specimens from two cosmopolitan earwig species: Euborellia annulipes (Fam. Anisolabididae) and Forficula auricularia (Fam. Forficulidae). Genomic DNA was extracted and, with the help of scientific teams that traveled to the schools, was sequenced using nanopore sequencers. The sequence data obtained for both species was assembled and annotated. We obtained genome sizes of 1.18 Gb (F. auricularia) and 0.94 Gb (E. annulipes) with the number of predicted protein coding genes being 31,800 and 40,000, respectively. Our analysis showed that we were able to capture a high percentage (≥ 93%) of conserved proteins indicating genomes that are useful for comparative and functional analysis. We were also able to characterize structural elements such as repetitive sequences and non-coding RNA genes. Finally, functional categories of genes that are overrepresented in each species suggest important differences in the process underlying the formation of germ cells, and modes of reproduction between them, features that are one of the distinguishing biological properties that characterize these two distant families of Dermaptera. CONCLUSIONS: This work represents an unprecedented instance where the scientific and lay community have come together to collaborate in a genome sequencing project. The versatility and accessibility of nanopore sequencers was key to the success of the initiative. We were able to obtain full genome sequences of two important and widely distributed species of insects which had not been analyzed at this level previously. The data made available by the project should illuminate future studies on the Dermaptera.

Determining the Cytosolic Stability of Small DNA Nanostructures In Cellula.

DNA nanostructures have proven potential in biomedicine. However, their intracellular interactions─especially cytosolic stability─remain mostly unknown and attempts to discern this are confounded by the complexities of endocytic uptake and entrapment. Here, we bypass the endocytic uptake and evaluate the DNA structural stability directly in live cells. Commonly used DNA structures─crosshairs and a tetrahedron─were labeled with a multistep Förster resonance energy transfer dye cascade and microinjected into the cytosol of transformed and primary cells. Energy transfer loss, as monitored by fluorescence microscopy, reported the structure's direct time-resolved breakdown in cellula. The results showed rapid degradation of the DNA crosshair within 20 min, while the tetrahedron remained consistently intact for at least 1 h postinjection. Nuclease assays in conjunction with a current understanding of the tetrahedron's torsional rigidity confirmed its higher stability. Such studies can inform design parameters for future DNA nanostructures where programmable degradation rates may be required.

Laser-Controlled Real- and Reciprocal-Space Topology in Multiferroic Insulators.

Magnetic materials in which it is possible to control the topology of their magnetic order in real space or the topology of their magnetic excitations in reciprocal space are highly sought after as platforms for alternative data storage and computing architectures. Here we show that multiferroic insulators, owing to their magnetoelectric coupling, offer a natural and advantageous way to address these two different topologies using laser fields. We demonstrate that via a delicate balance between the energy injection from a high-frequency laser and dissipation, single skyrmions-archetypical topological magnetic textures-can be set into motion with a velocity and propagation direction that can be tuned by the laser field amplitude and polarization, respectively. Moreover, we uncover an ultrafast Floquet magnonic topological phase transition in a laser-driven skyrmion crystal and we propose a new diagnostic tool to reveal it using the magnonic thermal Hall conductivity.

Health Indicators as Measures of Individual Health Status and Their Public Perspectives: Cross-sectional Survey Study.

BACKGROUND: Disease status (eg, cancer stage) has been used in routine clinical practice to determine more accurate treatment plans. Health-related indicators, such as mortality, morbidity, and population group life expectancy, have also been used. However, few studies have specifically focused on the comprehensive and objective measures of individual health status. OBJECTIVE: The aim of this study was to analyze the perspectives of the public toward 29 health indicators obtained from a literature review to provide evidence for further prioritization of the indicators. The difference between health status and disease status should be considered. METHODS: This study used a cross-sectional design. Online surveys were administered through Ohio University, ResearchMatch, and Clemson University, resulting in three samples. Participants aged 18 years or older rated the importance of the 29 health indicators. The rating results were aggregated and analyzed as follows (in each case, the dependent variables were the individual survey responses): (1) to determine the agreement among the three samples regarding the importance of each indicator, where the independent variables (IVs) were the three samples; (2) to examine the mean differences between the retained indicators with agreement across the three samples, where the IVs were the identified indicators; and (3) to rank the groups of indicators into various levels after grouping the indicators with no mean differences, where the IVs were the groups of indicators. RESULTS: In total, 1153 valid responses were analyzed. Descriptive statistics revealed that the top five-rated indicators were drug or substance abuse, smoking or tobacco use, alcohol abuse, major depression, and diet and nutrition. Among the 29 health indicators, the three samples agreed upon the importance of 13 indicators. Inferential statistical analysis indicated that some of the 13 indicators held equal importance. Therefore, the 13 indicators were categorized by rank into seven levels: level 1 included blood sugar level and immunization and vaccination; level 2 included LDL cholesterol; level 3 included HDL cholesterol, blood triglycerides, cancer screening detection, and total cholesterol; level 4 included health literacy rate; level 5 included personal care needs and air quality index greater than 100; level 6 included self-rated health status and HIV testing; and level 7 included the supply of dentists. Levels 1 to 3 were rated significantly higher than levels 4 to 7. CONCLUSIONS: This study provides a baseline for prioritizing 29 health indicators, which can be used by electronic health record or personal health record system designers or developers to determine what can be included in the systems to capture an individual's health status. Currently, self-rated health status is the predominantly used health indicator. Additionally, this study provides a foundation for tracking and measuring preventive health care services more accurately and for developing an individual health status index.

WiFi FTM and UWB Characterization for Localization in Construction Sites.

A high-precision location is becoming a necessity in the future Industry 4.0 applications that will come up in the near future. However, the construction sector remains particularly obsolete in the adoption of Industry 4.0 applications. In this work, we study the accuracy and penetration capacity of two technologies that are expected to deal with future high-precision location services, such as ultra-wide band (UWB) and WiFi fine time measurement (FTM). For this, a measurement campaign has been performed in a construction environment, where UWB and WiFi-FTM setups have been deployed. The performance of UWB and WiFi-FTM have been compared with a prior set of indoors measurements. UWB seems to provide better ranging estimation in LOS conditions but it seems cancelled by reinforcement concrete for propagation and WiFi is able to take advantage of holes in the structure to provide location services. Moreover, the impact of fusion of location technologies has been assessed to measure the potential improvements in the construction scenario.

Understanding Disorder, Vibronic Structure, and Delocalization in Electronically Coupled Dimers on DNA Duplexes.

Structural DNA nanotechnology is a promising approach to create chromophore networks with modular structures and Hamiltonians to control the material's functions. The functional behaviors of these systems depend on the interactions of the chromophores' vibronic states, as well as interactions with their environment. To optimize their functions, it is necessary to characterize the chromophore network's structural and energetic properties, including the electronic delocalization in some cases. In this study, parameters of interest are deduced in DNA-scaffolded Cyanine 3 and Cyanine 5 dimers. The methods include steady-state optical measurements, physical modeling, and a genetic algorithm approach. The parameters include the chromophore network's vibronic Hamiltonian, molecular positions, transition dipole orientations, and environmentally induced energy broadening. Additionally, the study uses temperature-dependent optical measurements to characterize the spectral broadening further. These combined results reveal the quantum mechanical delocalization, which is important for functions like coherent energy transport and quantum information applications.

Using contact-based education to destigmatize opioid use disorder among medical students.

CONTEXT: All first- and second-year (i.e., pre-clinical) medical students at a large, Midwestern medical school with three campuses were invited to participate in a two-arm, parallel educational study comparing the efficacy of two types of curricular interventions. Students at the main campus attended the modified contact-based education panel or the didactic lecture in person, while students at the two distance campuses attended the modified contact-based education or lecture remotely using the University's videoconferencing system. Impact: A total of 109 students participated in the study (average age 24.2 years (SD = 2.6), 64.2% female, 79.8% white, 56.0% second-year students, 67.9% attended on main campus, lecture = 52 participants, modified contact-based = 57 participants). Baseline responses were similar across groups. Following the session, participants in both interventions rated drug abuse (percent increase = 21.2%, p < .001) and prescription drug diversion (percent increase = 7.6%, p = .004) as more serious problems. Participants from both interventions expressed increased confidence in caring for patients with OUD (percent increase = 45.5%, p < .001) and increased interest in pursuing MAT training (percent increase = 21.5%, p = .04). Both curricular interventions were equally effective at reducing OUD stigma with a significant 8.2% decrease in total stigma scores and a large effect size (p < .001, ηp2 = .34). Lastly, participants with lower post-assessment OUD stigma scores were more likely to indicate that they would pursue additional training to provide MAT (p = .02). Lessons learned: Exposure to opioid-specific education with a focus on MAT and recovery, regardless of education type, positively affected opioid-related postgraduate intentions and reduced OUD stigma. Notably, these findings suggest that there are multiple efficacious techniques to reduce OUD stigma during preclinical training.

Spin Wave Radiation by a Topological Charge Dipole.

The use of spin waves (SWs) as data carriers in spintronic and magnonic logic devices offers operation at low power consumption, free of Joule heating. Nevertheless, the controlled emission and propagation of SWs in magnetic materials remains a significant challenge. Here, we propose that skyrmion-antiskyrmion bilayers form topological charge dipoles and act as efficient sub-100 nm SW emitters when excited by in-plane ac magnetic fields. The propagating SWs have a preferred radiation direction, with clear dipole signatures in their radiation pattern, suggesting that the bilayer forms a SW antenna. Bilayers with the same topological charge radiate SWs with spiral and antispiral spatial profiles, enlarging the class of SW patterns. We demonstrate that the characteristics of the emitted SWs are linked to the topology of the source, allowing for full control of the SW features, including their amplitude, preferred direction of propagation, and wavelength.

Magnonic Quadrupole Topological Insulator in Antiskyrmion Crystals.

We uncover that antiskyrmion crystals provide an experimentally accessible platform to realize a magnonic quadrupole topological insulator, whose hallmark signatures are robust magnonic corner states. Furthermore, we show that tuning an applied magnetic field can trigger the self-assembly of antiskyrmions carrying a fractional topological charge along the sample edges. Crucially, these fractional antiskyrmions restore the symmetries needed to enforce the emergence of the magnonic corner states. Using the machinery of nested Wilson loops, adapted to magnonic systems supported by noncollinear magnetic textures, we demonstrate the quantization of the bulk quadrupole moment, edge dipole moments, and corner charges.

Transducing Protease Activity into DNA Output for Developing Smart Bionanosensors.

DNA can process information through sequence-based reorganization but cannot typically receive input information from most biological processes and translate that into DNA compatible language. Coupling DNA to a substrate responsive to biological events can address this limitation. A two-component sensor incorporating a chimeric peptide-DNA substrate is evaluated here as a protease-to-DNA signal convertor which transduces protease activity through DNA gates that discriminate between different input proteases. Acceptor dye-labeled peptide-DNAs are assembled onto semiconductor quantum dot (QD) donors as the input gate. Addition of trypsin or chymotrypsin cleaves their cognate peptide sequence altering the efficiency of Förster resonance energy transfer (FRET) with the QD and frees a DNA output which interacts with a tetrahedral output gate. Downstream output gate rearrangement results in FRET sensitization of a new acceptor dye. Following characterization of component assembly and optimization of individual steps, sensor ability to discriminate between the two proteases is confirmed along with effects from joint interactions where potential for cross-talk is highest. Processing multiple bits of information for a sensing outcome provides more confidence than relying on a single change especially for the discrimination between different targets. Coupling other substrates to DNA that respond similarly could help target other types of enzymes.

Topological Magnons and Edge States in Antiferromagnetic Skyrmion Crystals.

Antiferromagnetic skyrmion crystals are magnetic phases predicted to exist in antiferromagnets with Dzyaloshinskii-Moriya interactions. Their spatially periodic noncollinear magnetic texture gives rise to topological bulk magnon bands characterized by nonzero Chern numbers. We find topologically protected chiral magnonic edge states over a wide range of magnetic fields and Dzyaloshinskii-Moriya interaction values. Moreover, and of particular importance for experimental realizations, edge states appear at the lowest possible energies, namely, within the first bulk magnon gap. Thus, antiferromagnetic skyrmion crystals show great promise as novel platforms for topological magnonics.

Energy Transfer with Semiconductor Quantum Dot Bioconjugates: A Versatile Platform for Biosensing, Energy Harvesting, and Other Developing Applications.

Luminescent semiconductor quantum dots (QDs) are one of the more popular nanomaterials currently utilized within biological applications. However, what is not widely appreciated is their growing role as versatile energy transfer (ET) donors and acceptors within a similar biological context. The progress made on integrating QDs and ET in biological configurations and applications is reviewed in detail here. The goal is to provide the reader with (1) an appreciation for what QDs are capable of in this context, (2) how this field has grown over a relatively short time span, and, in particular, (3) how QDs are steadily revolutionizing the development of new biosensors along with a myriad of other photonically active nanomaterial-based bioconjugates. An initial discussion of QD materials along with key concepts surrounding their preparation and bioconjugation is provided given the defining role these aspects play in the QDs ability to succeed in subsequent ET applications. The discussion is then divided around the specific roles that QDs provide as either Förster resonance energy transfer (FRET) or charge/electron transfer donor and/or acceptor. For each QD-ET mechanism, a working explanation of the appropriate background theory and formalism is articulated before examining their biosensing and related ET utility. Other configurations such as incorporation of QDs into multistep ET processes or use of initial chemical and bioluminescent excitation are treated similarly. ET processes that are still not fully understood such as QD interactions with gold and other metal nanoparticles along with carbon allotropes are also covered. Given their maturity, some specific applications ranging from in vitro sensing assays to cellular imaging are separated and discussed in more detail. Finally a perspective on how this field will continue to evolve is provided.

Students' Perceptions of Trigger Warnings in Medical Education.

Phenomenon: Trigger warnings are verbal statements or written warnings that alert students in advance to potentially distressing material. Medical education includes numerous subjects frequently identified as triggers, such as abuse, rape, self-injurious behaviors, eating disorders, drug and alcohol addiction, and suicide. Thus, exploring medical students' perceptions of trigger warnings may provide a valuable perspective on the use of these warnings in higher education. APPROACH: As part of a larger descriptive, cross-sectional survey study on medical education, we assessed 1st- and 2nd-year medical students' perceptions of trigger warnings in the preclinical curriculum. Five questions specific to trigger warnings explored students' knowledge, prior experience, and perceptions of trigger warnings in medical education. Frequencies of individual question responses were calculated, and qualitative data were analyzed via content and thematic analyses. FINDINGS: Of the 424 medical students invited to participate, 259 completed the survey (M = 24.8 years, SD + 3.4, 51.4% female, 76.1% White, 53.7% 1st-year students). Few students (11.2%) were aware of the term trigger warning and its definition. However, after being presented with a formal definition on the online survey, 38.6% reported having had a professor use one. When asked whether they supported the use of trigger warnings in medical education, respondents were distributed fairly equally by response (yes = 31.0%, maybe = 39.2%, no = 29.7%). Qualitative analysis revealed three themes: (a) Trigger Warnings Allow Students to Know What is Coming and Prepare Themselves: Respondents believed that trigger warnings would benefit students with a history of trauma by providing them additional time to prepare for the material and, if appropriate, seek professional help; (b) Students Need to Learn How to Handle Distressing Information: Respondents agreed that they needed to learn and cope with highly sensitive material because they would be confronted with difficult and unexpected situations in clinical practice; and (c) Trigger Warnings Help Students Understand the Severity of the Material: Respondents felt that trigger warnings may help students understand the severity of the material being covered and increase awareness about trauma and its effects on health and well-being. Insights: Findings did not reach consensus for or against the use of trigger warnings in medical school; however, students emphasized the importance of learning how to cope with distressing material. Trigger warnings may represent a teaching tool to facilitate classroom discussions about the severity of trauma-related material and problem-focused coping strategies.

Water-Soluble, Thermostable, Photomodulated Color-Switching Quantum Dots.

Photoswitchable probes are of great utility in fluorescence microscopy, permitting numerous determinations, including molecular localization for super-resolution, based on their modifiable emission intensity and spectra. We have coated a blue-emitting (425 nm) quantum dot (QD) with a diheteroarylethene photochrome (PCf), the closed form isomer of which has absorption and emission maxima at 440 and 520-530 nm, respectively, and thus functions as a fluorescent acceptor for the QD donor in Förster resonance energy transfer (FRET). The transition from the non-absorbing, non-fluorescent open state to the fluorescent closed state is achieved by irradiation in the near-UV and reversed by visible light. The PCf is coupled to an amphiphilic polymer that stably coats the QD, thereby creating a water-soluble color-switching QD (csQD) emitting in the blue after visible light irradiation and in the green after UV irradiation. Thus, csQDs photomodulate between two observable states, without the "off" state of previous constructs. The resulting change in the emission ratios of the QD and PCf is up to 180 %, and the csQD can undergo multiple photocycles with minimal fatigue.

Optical determination of the electronic coupling and intercalation geometry of thiazole orange homodimer in DNA.

Sequence-selective bis-intercalating dyes exhibit large increases in fluorescence in the presence of specific DNA sequences. This property makes this class of fluorophore of particular importance to biosensing and super-resolution imaging. Here we report ultrafast transient anisotropy measurements of resonance energy transfer (RET) between thiazole orange (TO) molecules in a complex formed between the homodimer TOTO and double-stranded (ds) DNA. Biexponential homo-RET dynamics suggest two subpopulations within the ensemble: 80% intercalated and 20% non-intercalated. Based on the application of the transition density cube method to describe the electronic coupling and Monte Carlo simulations of the TOTO/dsDNA geometry, the dihedral angle between intercalated TO molecules is estimated to be 81° ± 5°, corresponding to a coupling strength of 45 ± 22 cm-1. Dye intercalation with this geometry is found to occur independently of the underlying DNA sequence, despite the known preference of TOTO for the nucleobase sequence CTAG. The non-intercalated subpopulation is inferred to have a mean inter-dye separation distance of 19 Å, corresponding to coupling strengths between 0 and 25 cm-1. This information is important to enable the rational design of energy transfer systems that utilize TOTO as a relay dye. The approach used here is generally applicable to determining the electronic coupling strength and intercalation configuration of other dimeric bis-intercalators.

Report on the microbiota of Melipona quadrifasciata affected by a recurrent disease.

Melipona quadrifasciata is an eusocial stingless bee traditionally used for honey production in Brazil. In the last decades, the species disappeared from the wild in Southern Brazil, being kept exclusively in managed colonies for commercial and recreational purposes. Stingless beekeepers from this region report annual losses of their colonies due to a syndrome of yet unknown causes. We investigate whether it is associated to pathogenic microorganisms already known to cause disease in bees. These results provide a starting point for future studies aimed at clarifying the relationship between the microbial community of stingless bees and their colony collapses.