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Real-Time BioContact Assurance and Status Monitoring Using Human Body Communication
No full textReliable electrode-skin contact is essential for accurate biomedical signal acquisition, as poor contact leads to signal degradation and measurement errors in critical applications such as ECG, EEG, and EMG monitoring. Traditional lead-off detection methods face real-world challenges, including motion artifacts causing false detections, environmental noise reducing accuracy, and variations in skin-electrode impedance affecting reliability. To address these limitations, this paper presents a BioContact assurance system (BCAS) leveraging common-ground human body communication (CG-HBC) to continuously monitor electrode contact status. CG-HBC enables direct digital communication through the human body without complex modulation. The system consists of three core components: a CG-HBC transceiver, a processing unit, and an electrode interface module. The CG-HBC transceiver, fabricated using the TSMC 65 nm process, achieves 11.55 pJ/bit energy efficiency and consumes only 23.10 μW, making it suitable for seamless integration into wearable medical devices. A custom timing protocol synchronized with biomedical sampling ensures consistent and reliable contact monitoring. BCAS accurately classifies electrode conditions (connected, loose, intermittent, disconnected) in real time by analyzing the bit error rate and transmission success rate between electrode pairs, ensuring reliable contact assessment while maintaining signal quality. Unlike traditional DC/AC lead-off techniques, it detects subtle contact degradations with high sensitivity while sustaining robust performance for fully connected or disconnected states. These advancements highlight its promise for next-generation continuous health monitoring systems and intelligent biomedical wearables.The research reported in this publication was partially supported by funding from KAUST Center of Excellence for Smart Health, under award number #5932 and NEOM under award number #4819. The experiments were conducted with the approval of the Institutional Biosafety and Bioethics Committee (IBEC) under the reference number 20IBEC30
Pre-Crop Choice Shapes Nematode-Attached Bacterial Communities Associated With Reduced <scp><i>Pratylenchus penetrans</i></scp> Invasion of Barley Roots
No full textABSTRACTSoil microbiomes play a crucial role in plant–parasitic nematode suppression; however, the influence of plant–soil interactions remains unclear. This study examines plant–soil feedback effects on microbiomes attached to the cuticle of Pratylenchus penetrans in winter barley. We tested whether bacterial drivers of nematode suppression remain conserved across plant hosts or exhibit host specificity. Surface-sterilised P. penetrans were baited in different soils and rhizospheres, and their attached bacterial communities were analysed. Fallow and rhizosphere microbiomes from reduced P. penetrans invasion in barley, and suppression strength varied by plant species. Only the maize and Ethiopian mustard microbiomes inhibited invasion relative to other microbiomes and to surface-sterilised nematodes. By contrast, association with the oat microbiome did not reduce P. penetrans invasion of barley roots. The suppression of P. penetrans invasion relied on the cuticle-associated bacteria, with maize showing a distinct assembly rich in Proteobacteria and Firmicutes. Suppressive cuticle-associated bacteria differed between nematodes exposed to maize-derived and Ethiopian mustard-derived rhizosphere microbiomes from the same soil. Specific bacterial genera associated with reduced invasion included Chryseobacterium, Duganella, Streptomyces, Asticcacaulis, Pseudomonas, and members of Enterobacteriaceae. These results indicate that crop rotation and cover crop choices could steer nematode-associated microbiomes toward communities that prevent root invasion.The authors thank the technical members of the Heuer lab for their
excellent assistance in carrying out the experiments. This study was
funded by the German Research Foundation (DFG EL 1038/2-1)
Nanobody-Based Lateral Flow Assay for Rapid Zika Virus Detection
No full textZika virus infections remain severely underdiagnosed due to their initial mild clinical symptoms. However, recent outbreaks have revealed neurological complications in adults and severe deformities in newborns, emphasizing the critical need for accurate diagnosis. Lateral flow assays (LFAs) provide a rapid, cost-effective, and user-friendly method for antigen testing at point-of-care, bedside, or in home settings. LFAs utilizing nanobodies have multiple benefits over traditional antibody-based techniques, as nanobodies are much smaller, more stable, and simpler to manufacture. We introduce a nanobody-based LFA for the rapid identification of Zika virus antigens. Starting from two previously reported nanobodies recognizing the Zika nonstructural protein 1 (NS1), we evaluate periplasmic and cytosolic nanobody expression and test different purification tags and immobilization strategies. We quantify nanobody binding kinetics and validate their mutually noncompetitive binding. Avidity effects boost the capture of the tetrameric target protein by 3 orders of magnitude and point to a general strategy for higher sensitivity LFA sensing. The nanobody LFA detects Zika NS1 with a limit of detection ranging from 25 ng/mL in buffer to 1 ng/mL in urine. This nanobody-LFA has the potential to facilitate on-site and self-diagnosis, improve our understanding of Zika infection prevalence, and support public health initiatives in regions affected by Zika virus outbreaks.We thank H. Khurram for assistance in lab maintenance andprocurement. Experimental research was supported by theBioscience Core Lab, and ACL Proteomics Core Lab at KingAbdullah University of Science & Technology (KAUST) inThuwal, Saudi Arabia. The graphical abstract was created inBiorender.comThe research reported in this publication was supported byfunding from King Abdullah University of Science andTechnology (KAUST)�KAUST Center of Excellence forSmart Health (KCSH), under award number 5932, and theTranslational Research Grant Award no. RFS-TRG2024-6187
Warming Accelerates Phytoplankton Bloom Dynamics and Differentially Affects the Fluxes of Carbon, Nitrogen, and Oxygen Through a Coastal Microbial Community.
No full textMarine heatwaves affect the abundance and community structure of microbial plankton, with implications for food web and ecosystem processes, but their impact on microbially mediated elemental cycling remains poorly constrained. To determine the biogeochemical effects of increased temperature, we conducted an experiment in September 2023 in which a plankton community from a coastal, productive ecosystem (Ría de Vigo, NW Iberia) was exposed to a warming of + 2 °C and + 4 °C under unamended and nutrient-enriched conditions. The response of microbial plankton was characterized in terms of organic matter production, carbon fixation, nitrogen uptake, and oxygen net production. We found that warming caused increased nutrient consumption and biomass production, as well as faster bloom dynamics, both in unamended and nutrient-enriched treatments, indicating that the community was robust to thermal perturbation. Accelerated nutrient depletion under warming gave way to an earlier decrease in carbon fixation and nitrate uptake rates, together with a shift towards a negative or less positive metabolic balance. Carbon fixation was less sensitive than nitrate uptake to the different temperature and nutrient scenarios, leading to wide changes in the carbon-to-nitrogen uptake ratio, while respiration increased non-linearly with temperature. Overall, the investigated microbial fluxes were more responsive to nutrient availability than to temperature. Our results show that microbially driven ecosystem services in coastal waters have the potential to be enhanced during short-term warming events.We thank María Pérez-Lorenzo and Mercedes Peleteiro for their assistance with dissolved oxygen measurements and flow cytometry analysis.
Funding for open access publishing: Universidade de Vigo /CISUG. This study was supported by the Spanish Ministry of Science and Innovation through project POLARIS (PGC2018–094553-B-I00)
Varying effects of climate change on the photosynthesis and calcification of crustose coralline algae: Implications for settlement of coral larvae
No full textCoral recruitment is critical to the maintenance of healthy coral reef ecosystems. Many coral species settle preferentially on certain crustose coralline algae (CCA) (e.g., Hydrolithon boergesenii) over others (e.g., Paragoniolithon solubile). Calcifying organisms like CCA are particularly susceptible to ocean acidification (OA), and settlement behavior of larvae may be compromised as seawater temperatures increase (ocean warming; OW) and pH levels decrease as a result of climate change. Here, we examine the effects of future seawater conditions (OW and OA) on the calcification and photosynthetic efficiency of two CCA species, H. boergesenii and Pa. solubile. We also examine the effects of conditioning CCA in combined OA and OW on the settlement preferences of three coral species, Acropora palmata, A. cervicornis and Porites astreoides. Acropora palmata and Po. astreoides demonstrated a preference for H. boergesenii over Pa. solubile in choice experiments after short-term treatment (7–21 days) and this preference was not affected by future seawater conditions. A. cervicornis did not demonstrate a CCA preference under any treatment. Po. astreoides did not demonstrate a CCA preference in no-choice assays and settlement was unaffected by OW and OA even after the longest exposure (99 days). Both CCA had reduced photosynthetic efficiency after exposure to future seawater conditions. However, net calcification rate was reduced in H. boergesenii but not Pa. solubile after exposure to future seawater conditions. These results demonstrate that while climate change may differentially affect the physiological functioning of various species of CCA, coral settlement preferences are unlikely to be altered.We thank Nikki Fogarty, Alicia Vollmer, Megan Bock, Kelly Pitts, Zach Foltz, Molly Ashur, Zara Cowan, Jenn Joseph, and Skylar Carlson for assistance collecting CCA and coral larvae. Funding was provided by Mote Protect Our Reefs Grant program (POR 2016-7) and the Smithsonian Scholarly Studies Program. Belize Fisheries Department provided permits to conduct research at Carrie Bow Cay, Belize (permit #000009-17). In Florida, coral larvae and CCA were collected under permit #FKNMS-2017-015. This is SMSFP contribution #1233 and CCRE contribution #1085. This is publication #1792 from the Institute of Environment at Florida International University. We thank Julie Olson for sequencing support
Synergistic Ru Species on Poly(heptazine imide) Enabling Efficient Photocatalytic CO2 reduction with H2O Beyond 800 nm
No full textPhotocatalytic CO2 conversion with H2O to carbonaceous fuels is a desirable strategy for CO2 management and solar utilization, yet its efficiency remains suboptimal. Herein, efficient and durable CO2 photoreduction is realized over a RuNPs/Ru-PHI catalyst assembled by anchoring Ru single atoms (SAs) and nanoparticles (NPs) onto poly(heptazine imide) (PHI) via the in-plane Ru-N4 coordination and interfacial Ru-N bonds, respectively. This catalyst shows an unsurpassed CO production (32.8 μmol h-1), a record-high apparent quantum efficiency (0.26%) beyond 800 nm, and the formation of the valuable H2O2. Ru SAs tune PHI’s electronic structure to promote in-plane charge transfer to Ru NPs, forming a built-in electron field at the interface, which directs electron-hole separation and rushes excited electron movement from Ru-PHI to Ru NPs. Simultaneously, Ru SAs introduce an impurity level in PHI to endow long-wavelength photoabsorption, while Ru NPs strengthen CO2 adsorption/activation and expedite CO desorption. These effects of Ru species together effectively ensure CO2-to-CO conversion. The CO2 reduction on the catalyst is revealed to follow the pathway CO2→ *CO2→ *COOH→ *CO→ CO, based on the intermediates identified by in situ diffuse reflectance infrared Fourier transform spectroscopy and further supported by density functional theory calculations.This work was financially supported by the National Key R&DProgram of China (2021YFA1502100 and 2022YFE0114800), theNational Natural Science Foundation of China (U24A20567, 22372035, 22302039 and 22311540011) and the 111 Project(D16008)
Plant-specific adaptations of the CDC48 unfoldase
No full textTargeted protein degradation through the CDC48 unfoldase enables the maintenance and rapid adaptation of proteomes across eukaryotes. However, the profound differences between animals, fungi, and plants are expected to have led to a significant adaptation of the CDC48-mediated degradation. While animal and fungal CDC48 systems have shown structural and functional preservation, such analysis is lacking for plants. We determined the structural and functional characteristics of Arabidopsis thaliana CDC48A in various states and bound to the target-identifying cofactors UFD1 and NPL4. Our analysis reveals several features that distinguish AtCDC48 from its animal and yeast counterparts, despite an 80% sequence identity. Key features are that AtCDC48A displays distinct domain dynamics and interacts differently with AtNPL4. Moreover, AtNPL4 and AtUFD1 do not form an obligate heterodimer, but independently bind to AtCDC48A and mediate target degradation; however, their joint action is synergistic. An evolutionary analysis supports that these Arabidopsis features are conserved across plants and represent the ancestral state of eukaryotic CDC48 systems. Jointly, our findings support that plant CDC48 retains a greater modular and combinatorial cofactor usage, highlighting a specific adaptation of targeted protein degradation in plants.We would like to thank the Imaging and Characterization core lab, the Supercomputing Laboratories, and Bioscience core labs at KAUST for the use of their resources and support. We are grateful to ETH Zürich for access to the computational resources at ScopeM and Euler cluster
Molecular Insights into Bulk and Interfacial Properties of Brine Systems with Gas
No full textCarbon capture and storage (CCS) remains a crucial strategy for controlling CO2 emissions and combating climate change. Concurrently, Hydrogen has emerged as a promising clean and renewable energy resource to replace fossil fuels and facilitate the transition to a decarbonized society. In both technologies, fundamental understandings of the interfacial properties of the involved system is essential. Due to the difficulty associated with purification processes, the presence of impurities such as nitrogen can significantly influence the efficiency and safety of CO2 storage. In particular, capillary pressure plays a key role in determining CO2 migration, trapping, and storage security in deep saline aquifers and hydrocarbon reservoirs. Therefore, elucidating the effects of such impurities on capillarity is vital for accurate prediction and process optimization. In the context of hydrogen energy, cushion gases are commonly used to facilitate the withdrawal of hydrogen stored in saline aquifers and depleted oil and gas reservoirs. The bulk and interfacial properties of hydrogen–brine and cushion gas–brine systems critically affect the efficiency, economics, and environmental performance of subsurface hydrogen storage. In this dissertation,molecular dynamics simulations are employed to examine the interfacial properties of systems relevant to carbon capture and storage and hydrogen storage, including N2–oil–water mixtures, hydrogen–brine systems, and CO2–brine–silica systems. The results provide molecular-level insights that support the design and optimization of efficient, safe, and environmentally sustainable CCS and hydrogen-storage operations
Breaking the Specificity Barrier in Microwave Sensing: Highly Specific Lactate Microwave Biosensor for Fitness and Exercise Optimization
No full textNoninvasive biomarker sensing plays a vital role in health monitoring and sports physiology, particularly for tracking sweat lactate in real time to gauge exercise intensity without disrupting activity. This work introduces a high-specificity microwave biosensor for lactate detection, addressing the challenge of specificity seen in current microwave biosensors, which limits their practical applications. Our approach leverages a cost-effective complementary split-ring resonator (CSRR) combined with lactate oxidase (LOx) immobilized on spherical glass beads that act as mini-reactors within a microfluidic reservoir, enabling highly specific lactate sensing. The sensor was tested in phosphate buffer saline (PBS) and artificial sweat, achieving a high linear sensitivity of 10.9 and 11.3 MHz/mM, respectively, across lactate concentrations up to 150 mM and limit-of-detection (LOD) of 8.76 mM, with validation using the gold-standard HPLC method. It demonstrated excellent specificity against common interferences, including glucose, uric acid, and several ions. Testing with a diverse group of adult volunteers confirmed the sensor’s capability to detect dynamic lactate changes during exercise and reliably identify the lactate threshold (LT), underscoring its promise for applications in sports physiology. This innovative method not only offers a powerful tool for lactate monitoring but also paves the way for enzyme-specific microwave biosensors adaptable to detect a range of biomarkers by simply exchanging the target enzyme.This work was supported by the bassline funding from KAUST.The authors are grateful for KAUST core laboratories’ staff support throughout this work
Offline and Online KL-Regularized RLHF under Differential Privacy
No full textIn this paper, we study the offline and online settings of reinforcement learning from human feedback (RLHF) with KL-regularization -- a widely used objective function in large language model alignment -- under the local differential privacy (-LDP) model on the label of the human preference. In the offline setting, we design an algorithm based on the principle of pessimism and derive a new suboptimality gap of on the KL-regularized objective under single-policy concentrability. We also prove its optimality by providing a matching lower bound where is the sample size. In the online setting, we are the first one to theoretically investigate the problem of KL-regularized RLHF with LDP. We design an optimism-based algorithm and derive a logarithmic regret bound of , where is the total time step, is cardinality of the reward function space and is a variant of eluder dimension for RLHF. As a by-product of our analysis, our results also imply the first analysis for online KL-regularized RLHF without privacy. We implement our algorithm in the offline setting to verify our theoretical results and release our open source code at: https://github.com/rushil-thareja/PPKL-RLHF-Official.WethankWeiXiong, XingyuZhou, andYuhuiWangforinsightfuldiscussions. We wouldlike to acknowledge the MBZUAI SUFund and MIT–MBZUAI Collaborative Research Program for supporting this work