Structural Basis for Mitotic Centrosome Assembly in Flies.

In flies, Centrosomin (Cnn) forms a phosphorylation-dependent scaffold that recruits proteins to the mitotic centrosome, but how Cnn assembles into a scaffold is unclear. We show that scaffold assembly requires conserved leucine zipper (LZ) and Cnn-motif 2 (CM2) domains that co-assemble into a 2:2 complex in vitro. We solve the crystal structure of the LZ:CM2 complex, revealing that both proteins form helical dimers that assemble into an unusual tetramer. A slightly longer version of the LZ can form micron-scale structures with CM2, whose assembly is stimulated by Plk1 phosphorylation in vitro. Mutating individual residues that perturb LZ:CM2 tetramer assembly perturbs the formation of these micron-scale assemblies in vitro and Cnn-scaffold assembly in vivo. Thus, Cnn molecules have an intrinsic ability to form large, LZ:CM2-interaction-dependent assemblies that are critical for mitotic centrosome assembly. These studies provide the first atomic insight into a molecular interaction required for mitotic centrosome assembly.

Digital Intervention for behaviouR changE and Chronic disease prevenTION (DIRECTION): Study protocol for a randomized controlled trial of a web-based platform integrating nutrition, physical activity, and mindfulness for individuals with obesity.

Excess body weight, suboptimal diet, physical inactivity, alcohol consumption, sleep disruption, and elevated stress are modifiable risk factors associated with the development of chronic diseases. Digital behavioural interventions targeting these factors have shown promise in improving health and reducing chronic disease risk. The Digital Intervention for behaviouR changE and Chronic disease prevenTION (DIRECTION) study is a parallel group, two-arm, randomized controlled trial evaluating the effects of adding healthcare professional guidance and peer support via group-based sessions to a web-based wellness platform (experimental group, n = 90) compared to a self-guided use of the platform (active control group, n = 90) among individuals with a body mass index (BMI) of 30 to <35 kg/m2 and aged 40-65 years. Obesity is defined by a high BMI. The web-based wellness platform employed in this study is My Viva Plan (MVP)®, which holistically integrates nutrition, physical activity, and mindfulness programs. Over 16 weeks, the experimental group uses the web-based wellness platform daily and engages in weekly online support group sessions. The active control group exclusively uses the web-based wellness platform daily. Assessments are conducted at baseline and weeks 8 and 16. The primary outcome is between-group difference in weight loss (kg) at week 16, and secondary outcomes are BMI, percent weight change, proportion of participants achieving 5% or more weight loss, dietary intake, physical activity, alcohol consumption, sleep, and stress across the study. A web-based wellness platform may be a scalable approach to promote behavioural changes that positively impact health. This study will inform the development and implementation of interventions using web-based wellness platforms and personalized digital interventions to improve health outcomes and reduce chronic disease risk among individuals with obesity.

Myc Regulates Chromatin Decompaction and Nuclear Architecture during B Cell Activation.

50 years ago, Vincent Allfrey and colleagues discovered that lymphocyte activation triggers massive acetylation of chromatin. However, the molecular mechanisms driving epigenetic accessibility are still unknown. We here show that stimulated lymphocytes decondense chromatin by three differentially regulated steps. First, chromatin is repositioned away from the nuclear periphery in response to global acetylation. Second, histone nanodomain clusters decompact into mononucleosome fibers through a mechanism that requires Myc and continual energy input. Single-molecule imaging shows that this step lowers transcription factor residence time and non-specific collisions during sampling for DNA targets. Third, chromatin interactions shift from long range to predominantly short range, and CTCF-mediated loops and contact domains double in numbers. This architectural change facilitates cognate promoter-enhancer contacts and also requires Myc and continual ATP production. Our results thus define the nature and transcriptional impact of chromatin decondensation and reveal an unexpected role for Myc in the establishment of nuclear topology in mammalian cells.

National Institutes of Health COVID-19 Treatment Guidelines Panel: Perspectives and Lessons Learned.

DESCRIPTION: In March 2020, the White House Coronavirus Task Force determined that clinicians in the United States needed expert treatment guidelines to optimally manage patients with COVID-19, a potentially life-threatening disease caused by a new pathogen for which no specific treatments were known to be effective. METHODS: The U.S. Department of Health and Human Services requested that the National Institutes of Health (NIH) take the lead in expeditiously convening a panel of experts to create "living" guidelines that would be widely accessible and capable of frequent updating as important new information became available. RECOMMENDATIONS: The purpose of this article is to expand on the experiences of the NIH COVID-19 Treatment Guidelines Panel (the Panel) over the past 4 years, summarize the Panel's final recommendations for COVID-19, highlight some challenges and unanswered questions about COVID-19 management, and inform future responses to public health emergencies. The Panel was formed in March 2020, and the first iteration of the guidelines was released in April 2020. Now that the public health emergency has ended, the NIH COVID-19 Treatment Guidelines have sunsetted. This role will now fall to professional societies and organizations, such as the American College of Physicians, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the World Health Organization, all of which have been active in this area.

Bis-sulfonamido-2-phenylbenzoxazoles Validate the GroES/EL Chaperone System as a Viable Antibiotic Target.

We recently reported on small-molecule inhibitors of the GroES/GroEL chaperone system as potential antibiotics against Escherichia coli and the ESKAPE pathogens but were unable to establish GroES/GroEL as the cellular target, leading to cell death. In this study, using two of our most potent bis-sulfonamido-2-phenylbenzoxazoles (PBZs), we established the binding site of the PBZ molecules using cryo-EM and found that GroEL was the cellular target responsible for the mode of action. Cryo-EM revealed that PBZ1587 binds at the GroEL ring-ring interface (RRI). A cellular reporter assay confirmed that PBZ1587 engaged GroEL in cells, but cellular rescue experiments showed potential off-target effects. This prompted us to explore a closely related analogue, PBZ1038, which is also bound to the RRI. Biochemical characterization showed potent inhibition of Gram-negative chaperonins but much lower potency of chaperonin from a Gram-positive organism, Enterococcus faecium. A cellular reporter assay showed that PBZ1038 also engaged GroEL in cells and that the cytotoxic phenotype could be rescued by a chromosomal copy of E. faecium GroEL/GroES or by expressing a recalcitrant RRI mutant. These data argue that PBZ1038's antimicrobial action is exerted through inhibition of GroES/GroEL, validating this chaperone system as an antibiotic target.

Flowers meet Newton: testing the role of gravitational pull in resupination of orchid flowers.

Resupination refers to the developmental orientation changes of flowers through ≈180º, leaving them effectively upside-down. It is a widespread trait present in 14 angiosperm families, including the Orchidaceae, where it is a gravitropic phenomenon actively controlled by auxins. Here, we demonstrate that the passive gravitational pull on flower parts can have an additional influence on resupination. We studied a lady's slipper orchid in which some flowers naturally fail to resupinate. We conducted a manipulative experiment removing floral parts and showed that both the probability of complete resupination and the degree of flower vertical movement (from 0º - 180º) are related to the mass of floral organs. During flower development, the tip of the ovary slightly curves actively (14.75º) due to gravitropism. This promotes a lever arm effect so that the gravitational pull acting on flower mass creates a torque that bends the ovary, orienting the flower into a resupinate position that is accessible to pollinators. The role of the mass of floral organs in resupination provides new insights into flower development and its role in pollination mechanisms.

Anatomical validation of needle placement for cervical paraspinal mapping of the multifidus.

INTRODUCTION/AIMS: The paraspinal muscles are an important component of electrodiagnostic testing for radiculopathy. In the cervical region, a protocol for cervical paraspinal mapping assumes accurate placement of the electromyography (EMG) needle into the cervical multifidus. However, there is scant information regarding the accuracy of needle placement in that muscle. This study examines the accuracy of this protocol in sampling the intended multifidus muscle of cadavers. METHODS: An experienced electromyographer directed needles to multifidus at C5, C7, and T2 spinous processes of 19 embalmed cadavers, and injected color dyes. Separately another examiner dissected the cadavers, noting whether the dye was in the correct location and whether its trajectory approached any "danger zones" of nerve, artery, or joint. RESULTS: The dye was in the multifidus muscle 100% of the time and hit the intended bony target in 79%, 73%, and 79% of C5, C7, and T2 insertions. No insertion was found in a danger zone. DISCUSSION: The results indicate modest accuracy for EMG needle placement as proposed in the clinical protocol. Clinical utility of this method requires more work including the establishment of norms, sensitivities, specificities, and clinical impact.

Nectar cardenolides and floral volatiles mediate a specialized wasp pollination system.

Specialization in plant pollination systems can arise from traits that function as filters of flower visitors. This may involve chemical traits such as floral volatiles that selectively attract favoured visitors and non-volatile nectar constituents that selectively deter disfavoured visitors through taste or longer-term toxic effects or both. We explored the functions of floral chemical traits in the African milkweed Gomphocarpus physocarpus, which is pollinated almost exclusively by vespid wasps, despite having nectar that is highly accessible to other insects such as honeybees. We demonstrated that the nectar of wasp-pollinated G. physocarpus contains cardenolides that had greater toxic effects on Apis mellifera honeybees than on Vespula germanica wasps, and also reduced feeding rates by honeybees. Behavioural experiments using natural compositions of nectar compounds showed that these interactions are mediated by non-volatile nectar chemistry. We also identified volatile compounds with acetic acid as a main component in the floral scent of G. physocarpus that elicited electrophysiological responses in wasp antennae. Mixtures of these compounds were behaviourally effective for attraction of V. germanica wasps. The results show the importance of both volatile and non-volatile chemical traits as filters that lead to specialization in plant pollination systems.

Optimizing pain management in breast cancer care: Utilizing 'All of Us' data and deep learning to identify patients at elevated risk for chronic pain.

PURPOSE: The aim of the study was to develop a prediction model using deep learning approach to identify breast cancer patients at high risk for chronic pain. DESIGN: This study was a retrospective, observational study. METHODS: We used demographic, diagnosis, and social survey data from the NIH 'All of Us' program and used a deep learning approach, specifically a Transformer-based time-series classifier, to develop and evaluate our prediction model. RESULTS: The final dataset included 1131 patients. We evaluated the deep learning prediction model, which achieved an accuracy of 72.8% and an area under the receiver operating characteristic curve of 82.0%, demonstrating high performance. CONCLUSION: Our research represents a significant advancement in predicting chronic pain among breast cancer patients, leveraging deep learning model. Our unique approach integrates both time-series and static data for a more comprehensive understanding of patient outcomes. CLINICAL RELEVANCE: Our study could enhance early identification and personalized management of chronic pain in breast cancer patients using a deep learning-based prediction model, reducing pain burden and improving outcomes.

Module-Level Polaritonic Thermophotovoltaic Emitters via Hierarchical Sequential Learning.

Thermophotovoltaic (TPV) generators provide continuous and high-efficiency power output by utilizing local thermal emitters to convert energy from various sources to thermal radiation matching the bandgaps of photovoltaic cells. Lack of effective guidelines for thermal emission control at high temperatures, poor thermal stability, and limited fabrication scalability are the three key challenges for the practical deployment of TPV devices. Here we develop a hierarchical sequential-learning optimization framework and experimentally realize a 6″ module-scale polaritonic thermal emitter with bandwidth-controlled thermal emission as well as excellent thermal stability at 1473 K. The 300 nm bandwidth thermal emission is realized by a complex photon polariton based on the superposition of Tamm plasmon polariton and surface plasmon polariton. We experimentally achieve a spectral efficiency of 65.6% (wavelength range of 0.4-8 µm) with statistical deviation less than 4% over the 6″ emitter, demonstrating industrial-level reliability for module-scale TPV applications.

A phase 2 study of neoadjuvant chemotherapy plus durvalumab in resectable locally advanced head and neck squamous cell carcinoma.

BACKGROUND: Patients with locally advanced head and neck squamous cell cancer (HNSCC) are treated with surgery followed by adjuvant (chemo) radiotherapy or definitive chemoradiation, but recurrence rates are high. Immune checkpoint blockade improves survival in patients with recurrent/metastatic HNSCC; however, the role of chemo-immunotherapy in the curative setting is not established. METHODS: This phase 2, single-arm, multicenter study evaluated neoadjuvant chemo-immunotherapy with carboplatin, nab-paclitaxel, and durvalumab in patients with resectable locally advanced HNSCC. The primary end point was a hypothesized pathologic complete response rate of 50%. After chemo-immunotherapy and surgical resection, patients received study-defined, pathologic risk adapted adjuvant therapy consisting of either durvalumab alone (low risk), involved field radiation plus weekly cisplatin and durvalumab (intermediate risk), or standard chemoradiation plus durvalumab (high risk). RESULTS: Between December 2017 and November 2021, 39 subjects were enrolled at three centers. Oral cavity was the most common primary site (69%). A total of 35 of 39 subjects underwent planned surgical resection; one subject had a delay in surgery due to treatment-related toxicity. The most common treatment-related adverse events were cytopenias, fatigue, and nausea. Post treatment imaging demonstrated an objective response rate of 57%. Pathologic complete response and major pathologic response were achieved in 29% and 49% of subjects who underwent planned surgery, respectively. The 1-year progression-free survival was 83.8% (95% confidence interval, 67.4%-92.4%). CONCLUSIONS: Neoadjuvant carboplatin, nab-paclitaxel, and durvalumab before surgical resection of HNSCC were safe and feasible. Although the primary end point was not met, encouraging rates of pathologic complete response and clinical to pathologic downstaging were observed.

The economy of pollen dispersal in flowering plants.

Mating success of flowering plants depends strongly on the efficiencies of pollen removal from flowers and its subsequent dispersal to conspecific stigmas. We characterized the economy of pollen dispersal in flowering plants by analysing pollen fates and their correlates for 228 species. The mean percentage of pollen removed from flowers (removal efficiency) varied almost twofold according to the type of pollen-dispersal unit, from less than 45% for orchids and milkweeds with solid pollinia, to greater than 80% for species with granular monads or sectile (segmented) pollinia. The mean percentage of removed pollen reaching stigmas (pollen transfer efficiency, PTE) varied from 2.4% for species with separate monads to 27.0% for orchids with solid pollinia. These values tended to be higher in plants with single pollinator species and in those with non-grooming pollinators. Nectar production increased removal efficiency, but did not influence PTE. Among types of pollen-dispersal units, the net percentage of produced pollen that was dispersed to stigmas varied negatively with removal efficiency and positively with PTE, indicating the relative importance of the latter for overall pollen economy. These findings confirm the key importance of floral traits, particularly pollen packaging, for pollen dispersal outcomes and highlight the under-appreciated pollination efficiency of non-grooming pollinators.

'Bleeding' flowers of Ceropegia gerrardii (Apocynaceae-Asclepiadoideae) mimic wounded insects to attract kleptoparasitic fly pollinators.

Kleptomyiophily, where flowers imitate wounded insects to attract 'kleptoparasitic' flies as pollinators, is one of the most specialized types of floral mimicry and often involves physical trapping devices. However, the diversity of pollinators and functional floral traits involved in this form of mimicry remain poorly understood. We report a novel example of kleptomyiophily in the nontrapping flowers of Ceropegia gerrardii and explore the floral traits responsible for attracting pollinators. The pollinators, reproductive biology and floral traits (including epidermal surfaces, spectral reflectance and the composition of nectariferous petal secretions and scent) were investigated. Attractive volatiles were identified using electrophysiological and behavioural experiments. Ceropegia gerrardii was predominantly pollinated by kleptoparasitic Desmometopa spp. (Milichiidae) flies. The flower corollas extrude a protein- and sugar-containing secretion, similar to the haemolymph of wounded insects, on which the flies feed. Floral scent was chemically similar to that of injured honey bees. Four out of 24 electrophysiologically active compounds, all released by injured honey bees, were identified as key players in pollinator attraction. Our results suggest that C. gerrardii flowers chemically mimic wounded honey bees to attract kleptoparasitic flies and reward them with a secretion similar to the haemolymph on which they would normally feed.

Hiding images in noise.

A limitation of free-space optical communications is the ease with which the information can be intercepted. This limitation can be overcome by hiding the information within background optical noise. We demonstrate the transfer of images over free-space using a photon-pair source emitting two correlated beams. One of these beams contains image information, to which noise is added, and the other correlated beam is used as a heralding trigger so that the intended recipient can differentiate this image signal from the background noise. The system uses spontaneous parametric down-conversion to create photon-pairs with a wide spectral bandwidth and a gated intensified camera to extract the image from the background noise. The high-dimensionality of the image space means that the information content can be many bits per detected photon, whereas the heralding photon can be restricted to a single spatial-mode within a secure fiber which itself could be protected against interception by traditional low-dimensionality quantum key protocols.

Designing structures that maximize spatially averaged surface-enhanced Raman spectra.

We present a general framework for inverse design of nanopatterned surfaces that maximize spatially averaged surface-enhanced Raman (SERS) spectra from molecules distributed randomly throughout a material or fluid, building upon a recently proposed trace formulation for optimizing incoherent emission. This leads to radically different designs than optimizing SERS emission at a single known location, as we illustrate using several 2D design problems addressing effects of hot-spot density, angular selectivity, and nonlinear damage. We obtain optimized structures that perform about 4 × better than coating with optimized spheres or bowtie structures and about 20 × better when the nonlinear damage effects are included.

Transcending shift-invariance in the paraxial regime via end-to-end inverse design of freeform nanophotonics.

Traditional optical elements and conventional metasurfaces obey shift-invariance in the paraxial regime. For imaging systems obeying paraxial shift-invariance, a small shift in input angle causes a corresponding shift in the sensor image. Shift-invariance has deep implications for the design and functionality of optical devices, such as the necessity of free space between components (as in compound objectives made of several curved surfaces). We present a method for nanophotonic inverse design of compact imaging systems whose resolution is not constrained by paraxial shift-invariance. Our method is end-to-end, in that it integrates density-based full-Maxwell topology optimization with a fully iterative elastic-net reconstruction algorithm. By the design of nanophotonic structures that scatter light in a non-shift-invariant manner, our optimized nanophotonic imaging system overcomes the limitations of paraxial shift-invariance, achieving accurate, noise-robust image reconstruction beyond shift-invariant resolution.

Self-compression of femtosecond laser pulses in ambient air through conical radiation.

We demonstrate self-compression of 98 fs near-infrared laser pulses down to 8.8 fs in ambient air, utilizing self-phase modulation in air and negative dispersion in the properties of a laser-induced plasma. The blueshifted pulses achieve self-compression through conical radiation, eliminating the need for additional dispersion compensation. The results highlight a simple and compact approach to generate sub-10 fs laser pulses without additional measures for time-resolved applications in ultrafast diagnostics and spectroscopy.

Allosteric differences dictate GroEL complementation of E. coli.

GroES/GroEL is the only bacterial chaperone essential under all conditions, making it a potential antibiotic target. Rationally targeting ESKAPE GroES/GroEL as an antibiotic strategy necessitates studying their structure and function. Herein, we outline the structural similarities between Escherichia coli and ESKAPE GroES/GroEL and identify significant differences in intra- and inter-ring cooperativity, required in the refolding cycle of client polypeptides. Previously, we observed that one-half of ESKAPE GroES/GroEL family members could not support cell viability when each was individually expressed in GroES/GroEL-deficient E. coli cells. Cell viability was found to be dependent on the allosteric compatibility between ESKAPE and E. coli subunits within mixed (E. coli and ESKAPE) tetradecameric GroEL complexes. Interestingly, differences in allostery did not necessarily result in differences in refolding rate for a given homotetradecameric chaperonin. Characterization of ESKAPE GroEL allostery, ATPase, and refolding rates in this study will serve to inform future studies focused on inhibitor design and mechanism of action studies.

Does COVID-19 Infection Increase the Risk of Diabetes? Current Evidence.

PURPOSE OF REVIEW: Multiple studies report an increased incidence of diabetes following SARS-CoV-2 infection. Given the potential increased global burden of diabetes, understanding the effect of SARS-CoV-2 in the epidemiology of diabetes is important. Our aim was to review the evidence pertaining to the risk of incident diabetes after COVID-19 infection. RECENT FINDINGS: Incident diabetes risk increased by approximately 60% compared to patients without SARS-CoV-2 infection. Risk also increased compared to non-COVID-19 respiratory infections, suggesting SARS-CoV-2-mediated mechanisms rather than general morbidity after respiratory illness. Evidence is mixed regarding the association between SARS-CoV-2 infection and T1D. SARS-CoV-2 infection is associated with an elevated risk of T2D, but it is unclear whether the incident diabetes is persistent over time or differs in severity over time. SARS-CoV-2 infection is associated with an increased risk of incident diabetes. Future studies should evaluate vaccination, viral variant, and patient- and treatment-related factors that influence risk.

The conserved C2 phospholipid-binding domain in Delta contributes to robust Notch signalling.

Accurate Notch signalling is critical for development and homeostasis. Fine-tuning of Notch-ligand interactions has substantial impact on signalling outputs. Recent structural studies have identified a conserved N-terminal C2 domain in human Notch ligands which confers phospholipid binding in vitro. Here, we show that Drosophila ligands Delta and Serrate adopt the same C2 domain structure with analogous variations in the loop regions, including the so-called ß1-2 loop that is involved in phospholipid binding. Mutations in the ß1-2 loop of the Delta C2 domain retain Notch binding but have impaired ability to interact with phospholipids in vitro. To investigate its role in vivo, we deleted five residues within the ß1-2 loop of endogenous Delta. Strikingly, this change compromises ligand function. The modified Delta enhances phenotypes produced by Delta loss-of-function alleles and suppresses that of Notch alleles. As the modified protein is present on the cell surface in normal amounts, these results argue that C2 domain phospholipid binding is necessary for robust signalling in vivo fine-tuning the balance of trans and cis ligand-receptor interactions.