Real-time Gated Proton Therapy (RGPT) enables precise irradiation of moving targets and is an important motion-management technique in proton therapy. Uninterrupted continuous delivery (UCD), in which fluoroscopic X-rays remain on during proton irradiation, may improve beam stability and treatment efficiency, particularly in synchrotronbased systems using continuous beams. However, scattered fluoroscopic X-rays may be detected by the dose monitor (DM) and mistakenly counted as proton monitor units, potentially causing beam aborts. This study aimed to quantify scattered fluoroscopic X-rays detected by the DM during RGPT and evaluate their impact on beam delivery during simultaneous fluoroscopy and proton irradiation. Scattered fluoroscopic X-ray signals detected by the DM were measured using an RGPT system. Phantom experiments evaluated scattered X-ray dose rates while varying phantom thickness, fluoroscopic parameters, and range-shifter conditions. Beam-abort simulations were conducted under UCD conditions for both phantom and clinical liver cases.Abort probability was assessed as a function of proton MU per spot, scattered X-ray MU per frame, and fluoroscopy frame rate (FPS). DM signals from scattered fluoroscopic X-rays increased with tube voltage, tube current, field size, and phantom thickness, and were higher without a range shifter. The maximum dose rate was 0.0211 MU/frame at 125 kV, 80 mAs, 200 × 200 mm², and PW-30 cm without a range shifter, representing an 11.7-fold increase compared with in-air conditions. Beam-abort simulations showed abort proportions below 2% for monoenergetic fields and below 3% for clinical liver plans across all tested conditions. With the DM positioned closer to the X-ray tube, scattered fluoroscopic X-ray contamination increased with phantom thickness, differing from prior reports. Optimization of proton dose rate, imaging parameters, and system geometry can minimize beam interruptions, supporting the clinical feasibility of UCD.
Modern self-contained x-ray irradiators offer a safer alternative to radionuclide sources for preclinical radiation research and can deliver conformal, clinically relevant dose distributions. However, concerns persist regarding their performance and biological toxicity as direct replacements in radiobiological studies. We assessed two preclinical x-ray platforms, a collimated cabinet X-Rad320 and an image guided Small Animal Radiation Research Platform (SARRP), for induced tumor response, tolerability, and dosimetric accuracy in a subcutaneous xenograft prostate tumor model under 2-Gy daily fractionated radiotherapy. Male athymic mice bearing 22Rv1 xenografts were randomized into cohorts receiving total doses of 10, 16, or 20 Gy (5, 8, or 10 2-Gy fractions) on either platform. Unirradiated controls were included. Tumor burden was quantified by the area under the tumor growth curve (AUC). Machine dose delivery accuracy was verified quarterly with alanine pellet dosimetry. Across regimens, no animals met humane body condition or weight endpoints or exhibited overt clinical toxicity. All irradiated groups had lower tumor normalized AUCs than controls, but the dose response was not clearly monotonic, and not all differences remained statistically significant after correcting for multiple comparisons. At 14 d post-treatment, SARRP at 16 Gy provided the greatest tumor suppression, with no significant additional benefit observed with 20 Gy. Histological γ H2AX staining provided complementary evidence of a radiation-induced dose response. Focused x-ray platforms can reproducibly deliver conventional fractionated radiotherapy regimens in mice, inducing tumor response without overt clinical toxicity. However, platform-specific dose deviations highlight the need for rigorous dosimetric calibration and quality assurance to ensure they can effectively replace cesium-137 for in vivo research with comparable tumor control outcomes.
Lead exposure remains a major global health concern, contributing to an estimated 1.5% of annual deaths worldwide and causing widespread, irreversible neurodevelopmental and cardiovascular damage, particularly in children. A central challenge in understanding and mitigating lead toxicity is the determination of its chemical speciation in complex biological and environmental systems, where conventional Pb LIII-edge X-ray absorption spectroscopy (XAS) is fundamentally limited by severe core-hole lifetime broadening. Here we show that Pb Lα1 high-energy-resolution fluorescence-detected X-ray absorption spectroscopy (HERFD-XAS) provides a practical and experimentally accessible route to overcoming this limitation. Pb Lα1 HERFD-XAS yields an approximately 2-fold improvement in spectral resolution relative to conventional XAS, enabling enhanced sensitivity for quantitative speciation in heterogeneous and dilute systems. The method shows negligible chemical shifts (<0.06 eV) in the emission energy, simplifying implementation, distinguishes holodirected and hemidirected Pb(II) coordination environments, resolves biologically relevant Pb binding modes in zinc-finger model peptides, and identifies hemidirected Pb-substitution in hydroxyapatite, a key long-term reservoir of lead in humans. These results establish Pb Lα1 HERFD-XAS as a sensitive and experimentally accessible tool for determining Pb speciation in environmental and biological systems.
Chest X-Ray Vision-Language pretraining (VLP) leverages large-scale radiograph-report pairs to develop joint image-text representations, demonstrating significant potential for medical image diagnosis. However, existing VLP approaches often overlook the multi-view nature of chest X-Rays, and some multi-view methods apply uniform feature fusion, neglecting view-key semantic contributions. Moreover, random cross-modal Masked Language Modeling (MLM) fails to facilitate effective interactions, impeding representation alignment. Additionally, global alignment in VLP may lead to the false-negative problem. To address these limitations, we propose a novel medical VLP framework comprising three core components. First, a Key Semantics-enhanced Multi-view MLM module aggregates pathology-relevant patches across views, providing semantically rich supervision for MLM. A local semantics enhancing approach, which identifies and aggregates pathology-relevant key patches across views to guide MLM. Second, a Frontal-Lateral Alignment module extracts view-specific pathological features, ensuring semantic consistency and preserving critical information during aggregation. This module independently extracts pathological features from both views to preserve view-specific information while ensuring semantic consistency, which mitigates the loss of crucial information during aggregation. Third, a High-order Semantic Alignment approach mitigates false-negative issues by aligning features with semantically consistent clusters, enhancing global alignment through prototype-level semantics. Extensive experiments across seven public datasets demonstrate that our framework outperforms state-of-the-art methods in four downstream tasks, validating its efficacy. The code is available at https://github.com/sajiutea/F-L.
Accurate target localization in frameless stereotactic radiosurgery (SRS) is commonly achieved using intrafraction kV X-ray imaging, which contributes to patient imaging dose. In this study, the feasibility of reducing the imaging dose in CyberKnifeTM SRS by implementing copper (Cu) beam-hardening filtration while preserving image-guided targeting accuracy is investigated. Entrance Skin Dose (ESD) at isocenter was measured for standard aluminum (Al) filtration and additional Cu filtration thicknesses of 0.12 mm and 0.24 mm. Monte Carlo simulations were used to characterize Cu-induced X-ray spectral changes and to estimate imaging doses using patient-specific voxelized anatomical models over a range of tube potentials and filtration conditions. The effect of Cu filtration on targeting accuracy was assessed using End-to-End (E2E) tests, supplemented by patient image data. Copper filtration progressively removed low-energy photons, increasing the mean photon energy from 56 keV with standard Al filtration to 60 keV and 64 keV for 0.1 mm and 0.2 mm Cu filtration at 120 kVp. At 10 mAs, ESD increased from 0.248 mGy at 80 kVp to 0.822 mGy at 150 kVp with Al filtration, while addition of 0.12 mm and 0.24 mm Cu reduced ESD by 46% and 64% at 80 kVp and by 25% and 36% at 150 kVp, respectively. Patient model calculations confirmed meaningful organ dose sparing for the eye lenses, thyroid gland, and skin. For 6Dskull tracking, implementation of Cu filters induced modest image brightness/gradient error changes which were readily compensated by small kVp increase without mAs adjustment. For Xsight Spine and fiducial tracking algorithms registration performance was maintained with the addition of Cu filtration. E2E testing confirmed that the total system targeting error was maintained for all three tracking algorithms studied. Copper filtered imaging constitutes an effective strategy for optimizing imaging dose in the evaluated CyberKnife tracking workflows without compromising tracking accuracy.
Large quantities of dust particles are emitted from the arid and semi-arid regions of China, influencing atmospheric processes and climate from regional to global scales. The morphology and composition of dust particles govern their optical properties, reactivity, and transport behavior; thus, accurate single-particle information is essential for improving model representations and understanding their environmental effects. Here, we present the Dust Morphology and Composition from China's Source Regions (DMC-China) dataset. The dataset includes 541,074 individual dust particles generated via saltation-sandblasting processes from 55 surface soils collected from major dust source regions. The samples represent surface cover types, including gobi (gravel/desert pavement), sand dune, saline, desertified grassland and alluvial sediment surfaces. The particles were analyzed using computer-controlled scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (CCSEM-EDX), and strict quality control procedures ensured consistency and reliability across samples. Provided in accessible XLSX format with detailed metadata, DMC-China delivers comprehensive source-region profiles of nascent dust particle size, shape, and composition, offering a valuable foundation for studies of dust emission, long-range transport, and dust-related effects on climate and the environment.
Lanthanide coordination complexes are harnessed for biological imaging due to their oxidative stability in aqueous media, favorable relaxometric behavior, and accessible luminescence emissions within biomedically relevant, optical-imaging wavelength ranges. In contrast with multimodal imaging strategies that rely on exchanging lanthanide ions to access distinct modalities, we exploit the unique redox chemistry of the Eu2+/3+ pair to demonstrate the feasibility of multimodal imaging within a single chelate scaffold. We constructed a series of polypyridine-containing macrocyclic ligands that readily coordinate both Eu2+ and Eu3+ ions. Characterization of the corresponding chelates by X-ray crystallography, cyclic voltammetry, electron paramagnetic resonance spectroscopy, and photophysical measurements were conducted. The Eu2+-containing complexes of acetamide-functionalized, polypyridine-containing 18-membered macrocycles exhibit relaxometric properties comparable to clinical Gd3+ contrast agents for magnetic resonance imaging. Upon oxidation to Eu3+, the complexes display characteristic luminescence with quantum yields ranging from 1.3 to 13.9%. In situ sensitization with a Cherenkov-emitting radionuclide efficiently produces Eu3+ emission at concentrations comparable to those employed for Eu2+-enhanced magnetic resonance imaging. The complex that provided the greatest signal-to-noise ratio in magnetic resonance in vitro imaging studies, and when oxidized, produced a detectable, optical imaging signal with as little as 5 nmol of complex. A subsequent study in a murine xenograft tumor model demonstrated the feasibility of conducting sequential magnetic resonance and optical imaging experiments following single dose administration of the redox-switchable complex.
Electrocution, although uncommon in forensic practice, remains a significant cause of accidental death. We report a fatal case involving a 35-year-old singer who collapsed during a live performance. The autopsy revealed burn-like lesions on the hand holding the microphone, along with non-specific cutaneous lesions at multiple body sites. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) analysis identified numerous metallic particles on a toe and fewer particles on the hand. The detection of bismuth on the toe was unexpected and suggested an atypical electrocution mechanism involving a defective electrical cable containing a non-standard solder. This hypothesis was subsequently supported by expert evaluation of the electrical system. This case highlights the crucial role of SEM-EDS in the investigation of complex electrocution deaths. It emphasizes the need for careful examination of all cutaneous lesions, including those with atypical appearances, to detect potential evidence of electrical injury. In addition, the findings illustrate that metallization may occur at both the entry and exit points of the electric current, warranting cautious interpretation of lesion distribution.
Phase transitions are omnipresent in modern condensed matter physics and its applications. In solids, first-order phase transformations typically occur by nucleation and growth under nonequilibrium conditions. Under constant external conditions, e.g., constant annealing temperature and pressure, the nucleation and growth dynamics are often thought of as spatially and temporally independent. Here, in situ Bragg X-ray photon correlation spectroscopy (XPCS) reveals nanoscale spatial and dynamical heterogeneity in the perovskite-to-brownmillerite topotactic phase transformation in La0.7Sr0.3CoO3 thin films annealed under constant reducing conditions over a time span of multiple hours. Specifically, a time scale associated with domain growth remains stable, with a corresponding domain wall speed of vd = 6 ± 0.5 × 10-4 nm/s (2 ± 0.2 nm/h), while a slower time scale, associated with temperature-driven depinning of domains, leads to accelerating dynamics with time scales following an aging power law with exponent -2.2 ± 0.5. This experiment demonstrates that Bragg XPCS is a powerful tool to study nanoscale dynamics in structural phase transformations, with the ability to extract quantitative average values related to nanodomain motion in situ. The results are relevant for phase engineering of phase-change devices, as they show that nanoscale dynamics, linked to domain and domain-wall motion, can continuously evolve and speed up with time, even hours after the initiation of the phase transformation, with potential repercussions on electrical performance.
This study investigates the geochemical partitioning of arsenic (As) and antimony (Sb) in deposited dust collected from ventilation outlets of ten underground coal mines in Shanxi, with particular emphasis on potential mobility and associated ecological risks. Particle-size distribution, mineralogical characteristics, and bulk geochemical composition indicate that, relative to the corresponding parent coal, the deposited dust is dominated by fine mineral particles and enriched in clay minerals, carbonates, Fe-bearing phases, sulfate minerals, As, and Sb relative to the corresponding parent coal. Sequential extraction, TESCAN Integrated Mineral Analyzer (TIMA), and X-ray photoelectron spectroscopy (XPS) results further show that As is mainly partitioned into the residual (F8), surface-associated (F3), and acid-soluble fractions (F4), whereas Sb is predominantly concentrated in F8 and F4. These operationally defined fractions should be regarded as indicators of potential reactivity rather than direct measures of field mobility. A morphology- and scenario-adjusted risk index (MARI), derived from RI by assigning fraction-specific mobility-potential weights to As and Sb, shows that dust samples containing higher proportions of readily soluble and potentially reactive pools exhibit extremely high baseline relative risk (MARI = 781-813), and that this risk increases further under scenario-based acidic and low-oxygen conditions (MARI = 932-1016). Collectively, these findings suggest that environmental stressors may enhance the potential reactivity and relative ecological concern of As- and Sb-bearing dust, rather than directly demonstrating release at the field scale. Accordingly, effective management should prioritize focus on dust suppression, targeted environmental monitoring, and stabilization of reactive dust particles. Risk assessments should also incorporate operational partitioning and scenario-dependent sensitivity to improve the identification and prioritization of high-risk deposited dust from coal mine ventilation outlets.
X-ray repair cross-complementing protein 1 (XRCC1) protects cells from the effects of genotoxic stress by coordinating base excision repair (BER) and DNA single-strand break repair. XRCC1 phosphorylation and recruitment to sites of DNA damage are dependent on poly(ADP-ribose) polymerase-1 (PARP1) activity. As a central scaffolding protein, XRCC1 interacts with multiple components of BER pathway and also contributes to DNA double-strand break repair through the alternative nonhomologous end-joining pathway. In this regard, both established and recent studies have highlighted its critical role in spermatogenesis, extending beyond its classical association with PARP1. By integrating expression profiles with functional evidence, this review summarizes current insights into XRCC1 expression and subnuclear localization in spermatogenic cells, as well as its cooperative interaction with PARP1 in maintaining genomic integrity through efficient recombination and repair of genotoxic damage.
The contact application method of ethephon has drawbacks including rapid ethylene release, harmful effects of its products on the human body, and environmental pollution. A controlled-release and low-residue ethephon application technology can effectively address this issue. This study developed a simple and efficient ethylene slow-release technology: ethephon was mixed with porous starch (PS) and sodium alginate (SA) to form a complex via a mixing process, followed by coating a layer of hydroxypropyltrimethyl ammonium chloride chitosan (HACC) shell on its surface. The porous structure of PS provides sufficient loading and storage sites for ethephon. SA endows the composite with humidity responsiveness. HACC inhibits microbial growth by damaging cell membranes, thereby conferring antibacterial properties on the material. Compared with traditional ethylene slow-release technologies, this technology features lower cost, higher loading capacity, easy recyclability and environmental friendliness. Subsequently, the ratio of SA to PS was optimized, with the optimal ratio determined as 1:10. Under this ratio, the ethylene slow-release (ESR) complex achieves a maximum encapsulation efficiency of 52.17% and maintains stable ethylene release for over 120 h. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) analyses indicated that ethephon was physically combined with PS without altering the type-A crystal structure of PS. Ethylene release experiments showed that the complex with an ethephon concentration of 350 ppm achieved the optimal release effect, and the ethylene release rate was highly sensitive to humidity. In fruit application experiments, the ESR complex also performed excellently, achieving the dual goals of extending the edible window and preserving the nutritional quality of bananas and kiwifruits, and thus has broad application prospects in fruit ripening and preservation.
The widespread occurrence of microplastics (MPs) and nanoplastics (NPs) in natural environments, along with their associated potential health risks, has garnered significant scientific interest. Compared to MPs, NPs have a smaller particle diameter and a substantially larger surface-to-volume ratio. Therefore, NPs are hypothesized to pose a greater risk than MPs. In this study, we employed a multimodality approach combining pre-processing, transmission electron microscopy, and energy-dispersive X-ray spectroscopy to characterize NPs in natural water environments across China. Subsequently, we utilized commercially available fluorescent polystyrene NPs and MPs to conduct our biological comparisons. Flow cytometric analysis of RAW 264.7 cells revealed that NPs possess a markedly enhanced capacity to invade cells and provoke inflammatory responses compared to their MPs counterparts. Fluorescence imaging further demonstrated that NPs not only exhibit greater adhesion to food surfaces but also accumulate more readily than MPs in both adult zebrafish and their embryos. Finally, using uterine horn injection combined with Chicago blue staining, we confirmed that NPs induce more severe reproductive toxicity than MPs. The enhanced biological toxicity of NPs is likely attributable to their superior invasion and adhesion capability. Collectively, these findings provide a solid foundation for further investigations into the detrimental effects of NPs on human health.
Highly active and durable electrocatalysts for acidic oxygen evolution reaction (OER) remain a central challenge for proton-exchange-membrane water electrolyzers (PEMWEs). Here, we demonstrate that incorporating vanadium into Ir-Ru alloys changes the catalytic mechanism, resulting in increased OER performance. X-ray diffraction and high-resolution transmission electron microscopy studies indicate the Ir27Ru20V53 electrocatalyst exhibits pronounced lattice compression and shortened metal-metal bonds, which are associated with changes in d-d orbital interactions and the adsorption energetics of oxygen intermediates. Convergent evidence from the kinetic isotope effect (KIE) and kinetic probe studies using both methanol and tetramethylammonium suggests that the Ir27Ru20V53 electrocatalyst follows predominantly a direct O-O coupling pathway, rather than the conventional lattice oxygen-mediated mechanism (LOM) or adsorbate evolution mechanism (AEM) under which Ir-Ru catalysts operate. Operando attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) captures O-O intermediates, further supporting a direct O-O coupling pathway during the OER process catalyzed by the Ir27Ru20V53 electrocatalyst. The Ir27Ru20V53 electrocatalyst achieves a low overpotential of 213 mV at 10 mA cm-2 and a durability with a degradation rate of only 70 μV h-1 at a current density of 100 mA cm-2, determined in a PEMWE over 570 h. This work provides a design strategy for making high-performance low-Ir OER catalysts through the control of reaction mechanisms using early transition metals.
Histone deacetylase 6 (HDAC6) is a cytoplasmic enzyme that deacetylates non-histone substrates such as α-tubulin and cortactin. HDAC6 contains two catalytic domains, each containing a catalytic zinc ion, and a zinc-finger ubiquitin-binding domain. We have discovered BAS-2, a selective HDAC6 inhibitor with an isothiouronium core and no obvious zinc-binding group. To define its mechanism, we combine X-ray crystallography, structure-activity-relationships, molecular modeling and mutagenesis. BAS-2 potently inhibits human HDAC6 but it does not inhibit zebrafish HDAC6. Computational modeling highlighted Asp567 in human HDAC6 as critical for BAS-2 recognition and mutational analyses confirmed this. The corresponding zebrafish residue is Asn530 and the crystal structure of the N530D variant zHDAC6 revealed binding of a BAS-2-derived mercaptoacetamide that engages the catalytic zinc via strong thiolate-zinc coordination. Leveraging the orientation of BAS-2 binding, we designed a BAS-2-based proteolysis targeting chimera that induced proteasome-dependent HDAC6 degradation in cells, verified by global proteomics. Collectively, these insights clarify species selectivity and demonstrate that BAS-2 acts as a selective, mechanism-based inhibitor of human HDAC6. These discoveries will aid the development of the next generation of selective HDAC6 inhibitors and degraders.
The aim of this study was to examine whether a novel semi-automated dataset based on electronic health record documentation can be used for surveillance of central venous catheter-related mechanical complications (failed catheterisation, bleeding, cardiac arrhythmia, pneumothorax and nerve injury) within 24 hours of catheterisation. The semi-automated dataset comprised a fully automated extraction of clinical documentation from the electronic health record supplemented with a minor manual review aimed at identifying pneumothoraces as these rarely are diagnosed at the time of insertion but rather after a postprocedural chest X-ray. To assess surveillance performance, we compared the number of mechanical complications between the semi-automated and manually evaluated datasets for the same cohort and study period, focusing on agreement in aggregate counts. Comparisons were made at the group level only, without enforcing insertion-by-insertion matching. A total of 12 667 insertions were included. Minor mechanical complications occurred in 615 (4.9%) of the insertions in the semi-automated dataset and in 645 (5.1%) of the insertions in the manually validated dataset. Major mechanical complications occurred in 44 (0.35%) of the insertions in the semi-automated dataset compared to 48 (0.38%) in the manually validated dataset. A semi-automated dataset based on electronic health record documentation provides sufficiently accurate surveillance of central catheterisation related mechanical complications at the group level. Despite minor discrepancies, the semi-automated method enhances efficiency, scalability, and supports continuous real-time quality assurance. The potential underestimation of complication rates is offset by the possibility of robust real-time quality assurance in registries and a substantial analytical power in scientific studies.
Chemical pollution is a global threat to human health, yet the toxicity mechanisms of most contaminants remains unknown. Here, we applied an ultrahigh-throughput affinity selection-mass spectrometry (AS-MS) platform to systematically identify protein targets of prioritized chemical contaminants. After benchmarking the platform, we screened 50 human proteins against 481 prioritized chemicals, including 446 ToxCast chemicals and 35 per- and polyfluoroalkyl substances (PFAS). Among 24,050 interactions assessed, we discovered 35 interactions involving 13 proteins, with fatty acid-binding proteins (FABPs) emerging as the most ligandable protein family. Given this, we selected FABPs for further validation, which revealed a distinct PFAS binding pattern: legacy PFAS selectively bound to FABP1, whereas replacement compounds, perfluoroether carboxylic acids, unexpectedly interacted with all FABPs. X-ray crystallography further revealed that the ether group enhances the molecular flexibility of alternative PFAS to accommodate the binding pockets of FABPs. Our findings demonstrate that AS-MS is a robust platform for the discovery of protein targets beyond the scope of ToxCast and highlight the broader protein-binding spectrum of alternative PFAS as potential regrettable substitutes.
Wrong-side diagnostic imaging order errors are preventable errors that can delay diagnosis and cause patient harm yet remain underdetected due to limitations in existing reporting systems. To develop and validate an automated electronic health record (EHR)-based method for detecting potential wrong-side diagnostic imaging order errors using an adapted Retract-and-Reorder (RAR) approach and to identify associated risk factors. Retrospective cohort study. Six-facility health system comprising inpatient, outpatient and emergency room sites. We screened 355 000 imaging orders with side specified, placed during 2021 across our healthcare system. We adapted the RAR methodology, originally developed to detect near-miss medication errors, by extending detection windows to 24 hours and identifying any orders switching from one side to the contralateral side, accounting for multiprovider workflows inherent in imaging. We validated the method through chart review of 100 randomly selected RAR events, then applied the query across all imaging orders. Multivariate logistic regression was used to identify risk factors associated with RAR events. We identified 1667 RAR events (4.70 per 1000 orders). Validation yielded a positive predictive value of 87% (95% CI 79.0% to 92.2%), estimating 4.09 confirmed wrong-side errors per 1000 orders. The odds of an RAR event were significantly higher in outpatient settings compared with inpatient settings (OR 4.53; 95% CI 3.80 to 5.42) and among administrative staff compared with attending physicians (OR 2.08; 95% CI 1.73 to 2.49). CT scans showed 79% higher odds of an RAR event compared with X-rays (OR 1.79; 95% CI 1.34 to 2.39). This validated approach offers a scalable solution for automated detection of potential wrong-side diagnostic imaging order errors. The methodology leverages commonly available EHR data to support continuous surveillance and intervention evaluation for improved diagnostic safety.
Advances in structural biology have improved our understanding of the relationship between protein structure and function, while also confirming a widely applicable principle: protein domains with highly conserved three-dimensional folds can perform radically disparate biochemical functions. To gain insight into this structural enigma, we mapped the energetic landscapes of a family of bacterial transcription factors and their anciently diverged structural homologues, the periplasmic binding proteins. Using hydrogen exchange-mass spectrometry, bioinformatics, X-ray crystallography and molecular dynamics, we uncovered an unexpected contrast: despite binding the same sugars, the two families have evolved unique 'energetic blueprints' to support their distinct functional requirements. To test if differences in ensemble energies have functional consequences, we rationally redesigned the protein fold for tunable ligand-driven transcriptional responses. Strikingly, energy-driven protein engineering produced synthetic transcription factors with the theoretically anticipated ligand-induced transcriptional outputs. Thus, decoding energetic blueprints among conserved protein folds provides diverse functional adaptations, paves an alternative roadmap for protein design, and offers a distinct approach for engineering challenging drug targets.
To characterize unilateral and bilateral masticatory myofascial pain (MMP) in a clinical cohort. Patients meeting criteria for MMP according to the Research Diagnostic Criteria for Temporomandibular Disorders were recruited over a 2-year period. Demographic and clinical date were recorded. Data for unilateral and bilateral pain were analysed using Mann-Whitney U, Kruskal-Wallis H, and Fisher's Exact tests. Variables showing a p < 0.2 were entered into a binary logistic regression model, with pain laterality as the dependent variable. Patients with unilateral pain exhibited muscle tenderness both ipsilaterally and bilaterally, and patients with bilateral pain likewise demonstrated tenderness bilaterally and unilaterally. Unilateral pain was significantly associated with pain-related awakening (p = 0.03), nausea (p = 0.01), and primary pain (p = 0.01). These associations were confirmed in the regression analysis. Patients with unilateral and bilateral pain were similar in demographic characteristics. Unilateral and bilateral masticatory muscle pain differ in three clinical domains. Unilateral pain is significantly associated with pain-related awakening, primary pain, and nausea. The significance of these findings needs further study in a larger cohort. Additionally, the potential relationship between unilateral/bilateral MMP and headache warrants further investigation.