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Fang, S.

Publications and source records attributed to Fang, S..

At least 37 records · Page 2Linked to original sources

DynPerturb:Dynamic Perturbation Modeling for Spatiotemporal Single-Cell Systems

Perturbation responses in multicellular systems are inherently spatiotemporal, governed by temporal dynamics, perturbation intensity, and tissue context. However, existing approaches rarely capture explicit spatiotemporal perturbation dynamics, limiting the ability to reconstruct how perturbations propagate over time, spread across space, and induce feedback at multiple biological scales. Here we introduce DynPerturb, a dynamic inference framework for single-cell and spatial transcriptomics that systematically models the "when-how strong-where" dimensions of perturbations. DynPerturb incorporates temporal encoding, spatial adjacency, and memory modules to capture nonlinear signal propagation and cross-regional feedback with mechanistic interpretability. Across temporal benchmarking datasets, DynPerturb consistently outperformed existing methods in regulatory link prediction, demonstrated zero-shot generalization to unseen nodes, and preserved accuracy under varying sparsity conditions and temporal resolutions. Applied to representative biological systems, DynPerturb uncovers dynamic regulatory rewiring in kidney disease, highlighting a mid-age sensitivity window and potential reversibility with early intervention; delineated a temporal fate-switching boundary between megakaryocyte-erythroid progenitors (MEPs) and granulocyte-monocyte progenitors (GMPs) during hematopoiesis; and revealed spatiotemporal interchamber signaling in murine heart development, where Igf2 perturbations induced spatial feedback shaping chamber proportioning. Collectively, these results establish DynPerturb as a unified and versatile system for dissecting dynamic perturbation effects and guiding precision intervention strategies in multicellular systems.

bioinformatics↗

Iron Metabolism and Antioxidant Defense: The Role of LI-rTMS in Cerebral Ischemia-Reperfusion

BACKGROUNDTreating cerebral ischemia/reperfusion injury (CIRI) is challenging, with iron metabolism imbalances and oxidative stress worsening the condition. While low-intensity repetitive transcranial magnetic stimulation (LI-rTMS) shows potential in brain protection, its effects on iron processing and antioxidant use are unclear. This study explored LI-rTMSs role in regulating iron homeostasis and antioxidant defense for potential therapeutic use in CIRI. METHODSA rat model of CIRI was established using a filament insertion technique, followed by neurological and infarct volume assessments. In PC12 cells, oxidative damage was induced with H2O2 or ferric ammonium citrate (FAC), then treated with LI-rTMS or deferoxamine (DFP). Parameters measured included oxidative stress markers, iron metabolism markers, and mitochondrial integrity. Gene knockdown and overexpression experiments explored mechanisms involving LI-rTMS and ACSL4. RESULTSLI-rTMS improved neurological deficits by boosting GPX4 activity and inhibiting the ACSL4-LPCAT3-LOX axis, reducing lipid peroxidation. It restored iron balance by lowering TFR and DMT1, decreasing ferritin and hepcidin, and increasing FPN for better iron efflux. LI-rTMS also prevented the Fenton reaction, reduced ROS production, and maintained mitochondrial structure and transmembrane potential. CONCLUSIONSLI-rTMS offers neuroprotection by regulating iron homeostasis through dual pathways: boosting export (via FPN) and reducing uptake/storage (via TFR/DMT1/FE). It also provides ACSL4-dependent antioxidant benefits, suggesting its potential to prevent ferroptosis in CIRI.

biophysics↗

Bioactive 3D-bioprinted scaffolds with endothelial progenitor cells and Zn2+-enhanced SFMA/HisMA/nHAP for healing of infected bone defect

Infected bone defects remain one of the greatest challenges in orthopedics, as bacterial contamination and insufficient vascularization severely compromise regeneration. Here, we report the development of a multifunctional 3D-bioprinted scaffold composed of zinc ion (Zn{superscript 2}{square}) functionalized silk fibroin methacryloyl (SFMA), histidine methacryloyl (HisMA), and nano-hydroxyapatite (nHAP), further loaded with endothelial progenitor cells (EPCs) to promote simultaneous antibacterial, angiogenic, and osteogenic responses. The photocrosslinkable SFMA/HisMA bio-ink reinforced with nHAP provided mechanical stability, controlled swelling and degradation, while Zn{superscript 2}{square} coordination endowed strong antibacterial activity against E. coli and S. aureus. EPCs adhered and proliferated on the scaffolds, and in co-culture with bone marrow stromal cells (BMSCs) markedly enhanced osteogenic differentiation, as evidenced by increased expression of OCN, RUNX2, COL1, and OPN. Proteomic profiling further revealed that EPC-loaded scaffolds modulated osteoblast protein expression patterns consistent with both immunoregulation and active extracellular matrix reconstruction to promote tissue regeneration. In a murine femoral infected defect model, EPC-loaded scaffolds suppressed pro-inflammatory cytokines (IL-6, TNF-), stimulated angiogenesis, and supported robust new bone formation, leading to accelerated defect repair confirmed by {micro}CT and histological analyses. Together, these findings demonstrate that the EPC-loaded Zn{superscript 2}{square} functionalized SFMA/HisMA/nHAP scaffold integrates antibacterial defence with vascular and osteogenic stimulation, offering a promising translational strategy for the treatment of complex infected bone defects. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=145 SRC="FIGDIR/small/676384v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@1a75a57org.highwire.dtl.DTLVardef@1c32b6org.highwire.dtl.DTLVardef@1456159org.highwire.dtl.DTLVardef@1fa5321_HPS_FORMAT_FIGEXP M_FIG C_FIG Schematic illustration of materials synthesis and application. Silk fibroin was modified with glycidyl methacrylate (GMA) to obtain silk fibroin methacryloyl (SFMA), while histidine was functionalized with acryloyl chloride to generate histidine methacryloyl (HisMA). SFMA and HisMA were then combined and coordinated with Zn{superscript 2}{square} ions and incorporated with nHAP to form the full-component bioactive scaffold (SFMA/HisMA/nHAP/Zn{superscript 2}{square}). The resulting material can be 3D-printed and loaded with endothelial progenitor cells (EPCs) to yield a multifunctional scaffold with antibacterial activity, pro-osteogenic and pro-angiogenic properties, favorable physicochemical characteristics, and excellent biocompatibility, making it a promising candidate for the treatment of infected bone defects.

bioengineering↗

Neurophysiological Sensitivity to Envelope and Pulse Timing Interaural Time Differences in Cochlear Implanted Rats with Different Hearing Experiences

Cochlear implants (CIs) have successfully restored hearing in more than one million patients with severe to profound hearing loss worldwide. While CIs effectively restore speech perception in quiet environments, sound localization remains challenging for bilateral CI users, particularly their ability to utilize interaural time differences (ITDs). The majority of clinical CI processors use a coding strategy that encodes ITD information only in the envelope of electrical pulse trains rather than their pulse timing, which may contribute to the poorer spatial hearing perception of CI users. We recently demonstrated in a behavioral study on early deafened, bilaterally CI-implanted rats that pulse timing ITDs completely dominate ITD perception, while sensitivity to envelope ITDs is almost negligible in comparison. Building on this, we here investigated the neurophysiological sensitivity of the inferior colliculus (IC) to envelope and pulse timing ITDs at two different pulse rates (900 and 4500 pulses/s) and three different stimulation modulations (5, 20 and 100 Hz) in CI rats with different hearing experiences. Our results indicate that IC neurons exhibit far greater sensitivity to pulse timing ITD than envelope ITD independent of pulse rate, modulation rate or hearing experience. These findings suggest that to improve binaural hearing outcome in bilateral CI users, clinical stimulation strategies should provide informative pulse timing ITDs. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=131 SRC="FIGDIR/small/675523v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@1874d3borg.highwire.dtl.DTLVardef@1df79feorg.highwire.dtl.DTLVardef@c244e5org.highwire.dtl.DTLVardef@39220f_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Multi-omics reveals lipid metabolism, mitochondrial and extracellular matrix dysregulation of diabetic cardiomyopathy in the human heart

Diabetic cardiomyopathy (DbCM) is a condition characterized by myocardial dysfunction in diabetes. Although the clinical recognition of DbCM is increasing, its underlying molecular mechanisms remain poorly understood. We aimed to conduct a comprehensive multi-omics analysis of heart tissue from cardiomyopathy patients (both with and without diabetes),alongside tissue from healthy donors, by integrating transcriptomic, 4D-DIA proteomic, and full-spectrum widely targeted metabolomic data. Differential analyses revealed a significant metabolic pattern in patients with DbCM, characterized by increasing utilization of triglyceride-derived fatty acids. Correlation analyses highlighted impaired BNIP3L-mediated mitophagy as a potential contributor to the disruption of fatty acid metabolism and mitochondrial dysfunction in DbCM. Protein interaction and fibrotic trichrome analyses showed that patients with DbCM had impaired cardiac matrix repair compared to patients with cardiomyopathy without diabetes. These findings provide a system-level understanding of DbCM and reveal molecular signatures driving its progression, offering insights for targeted therapeutic strategies against diabetic heart disease.

bioinformatics↗

An Anisotropic Reactive Viscoelastic Model of the Rhesus Macaque Cervix for Studying Cervical Remodeling

The uterine cervix is a soft biological tissue with critical biomechanical functions in pregnancy. It is a mechanical barrier that supports the growing fetus. As pregnancy progresses, the cervix becomes more compliant and eventually opens in late pregnancy to facilitate childbirth. This dual function is facilitated by extensive remodeling of the cervical extracellular matrix (ECM), giving rise to its complex time-dependent material properties. Premature cervical remodeling is known to result in preterm birth, defined as birth before 37 weeks of gestation. While previous work has studied cervical remodeling using various biomechanical methods, it remains unclear how the intrinsic or flow-independent viscoelastic behavior of the cervix is influenced by cervical remodeling. In this study, an anisotropic reactive viscoelastic material model was formulated and investigated under tensile deformation to understand material behavior in cervical remodeling. To calibrate the model, experimental force relaxation data was used from uniaxial tension tests on Rhesus macaque cervical specimens from four gestational time points. The results showed that cervical tissue equilibrium and instantaneous stiffness significantly decreased from the non-pregnant to the late pregnancy status. In addition, cervical tissue in the late third trimester relaxed faster to equilibrium than the other gestational groups, particularly at prescribed tensile strains greater than 30%. This fast relaxation to equilibrium helps the cervix dissipate tensile hoop stresses induced by the fetus during labor, preventing its rupture. This work provides insights into time-dependent cervical remodeling features, which are crucial for developing diagnostic methods and treatments for preterm birth.

bioengineering↗

UniCell: Towards a Unified Solution for Cell Annotation, Nomenclature Harmonization, Atlas Construction in Single-Cell Transcriptomics

Standardizing cell type annotations across single-cell RNA-seq datasets remains a major challenge due to inconsistencies in nomenclature, variation in annotation granularity, and the presence of rare or previously unseen populations. We present UniCell, a hierarchical annotation framework that combines Cell Ontology structure with transcriptomic data for scalable, interpretable, and ontology-aware cell identity inference. UniCell leverages a multi-task architecture that jointly optimizes local and global classifiers, yielding coherent predictions across multiple levels of the ontology-defined hierarchy. When benchmarked across 20 human and mouse datasets, UniCell consistently outperformed state-of-the-art tools, including CellTypist, scANVI, OnClass, and SingleR, in annotation performance, and sensitivity to low-abundance populations. In disease settings, UniCell effectively identified previously unseen cell types through confidence-guided novelty detection. Applied to 45 human and 23 mouse tissue atlases, UniCell enabled cross-dataset and cross-species harmonization by embedding cells into a unified latent space aligned with Cell Ontology structure. Moreover, when used to supervise single-cell foundation models, UniCell substantially improved downstream annotation accuracy, rare cell detection, and hierarchical consistency. Together, these results establish UniCell as a generalizable framework that supports high-resolution annotation, nomenclature standardization, and atlas-level integration, providing a scalable and biologically grounded solution for single-cell transcriptomic analysis across diverse biological systems.

bioinformatics↗

Integration of the hammerhead ribozyme into structured RNAs to measure ligand-binding events for riboswitch candidates and aptamers

Some structured RNAs, such as riboswitches and aptamers, can bind their cognate ligands and have been used in biosensors and gene expression control elements. However, current methods for detecting ligand binding to structured RNAs are either severely limited or inconvenient. In this study, we design a multi-base pair bridge to integrate a hammerhead ribozyme into structured RNAs to detect ligand binding events. The experimental results demonstrate that the length of the bridge has a significant effect on the cleavage of the ribozyme; optimal cleavage can be achieved with three to six base pairs in the bridge. The dissociation constant (KD) values obtained through this method are in agreement with those determined by in-line probing techniques, and 1 pmol of allosteric ribozyme RNA is sufficient for measurement. We apply this method to evaluate the binding affinity of the riboswitch candidate Motif_9307. Our findings indicate that this motif has no binding affinity for S-adenosylmethionine or several other tested ligands, which is consistent with the results of the in-line probing experiments. Notably, our method reveals an increase in cleavage activity when yeast extract is added as a mixture of ligands, suggesting that the ligand of Motif_9307 is present in the extract. In conclusion, we develop an alternative approach for measuring ligand binding events associated with riboswitch candidates and aptamers.

molecular biology↗

A Sensitive Soma-localized Red Fluorescent Calcium Indicator for Multi-Modality Imaging of Neuronal Populations In Vivo

Recent advancements in genetically encoded calcium indicators, particularly those based on green fluorescent proteins, have optimized their performance for monitoring neuronal activities in a variety of model organisms. However, progress in developing red-shifted GECIs, despite their advantages over green indicators, has been slower, resulting in fewer options for end-users. In this study, we explored topological inversion and soma-targeting strategies, which are complementary to conventional mutagenesis, to re-engineer a red genetically encoded calcium indicator, FRCaMP, for enhanced in vivo performance. The resulting sensors, FRCaMPi and soma-targeted FRCaMPi (SomaFRCaMPi), exhibit up to 2-fold higher dynamic range and peak {Delta}F/F0 per single AP compared to widely used jRGECO1a in neurons in culture and in vivo. Compared to jRGECO1a and FRCaMPi, SomaFRCaMPi reduces erroneous correlation of neuronal activity in the brains of mice and zebrafish by two- to four-fold due to diminished neuropil contamination without compromising the signal-to-noise ratio. Under wide-field imaging in primary somatosensory and visual cortex in mice with high labeling density (80-90%), SomaFRCaMPi exhibits up to 40% higher SNR and decreased artifactual correlation across neurons. Altogether, SomaFRCaMPi improves the accuracy and scale of neuronal activity imaging at single-neuron resolution in densely labeled brain tissues due to a 2-3-fold enhanced automated neuronal segmentation, 50% higher fraction of responsive cells, up to 2-fold higher SNR compared to jRGECO1a. Our findings highlight the potential of SomaFRCaMPi, comparable to the most sensitive soma-targeted GCaMP, for precise spatial recording of neuronal populations using popular imaging modalities in model organisms such as zebrafish and mice.

neuroscience↗

RegFormer: A Single-Cell Foundation Model Powered by Gene Regulatory Hierarchies

Single-cell RNA sequencing (scRNA-seq) enables high-resolution profiling of cellular diversity, but current computational models often fail to incorporate regulatory priors, handle data sparsity, or efficiently process long gene sequences. Here, we present RegFormer, a foundation model that integrates gene regulatory networks (GRNs) with Mamba-based state-space modeling, overcoming the scalability and context-length limitations of Transformer architectures. RegFormer encodes each gene through dual embeddings, a value embedding for quantitative expression and a token embedding for regulatory identity, organized within a GRN-guided gene order to capture both expression dynamics and hierarchical regulation. Pretrained on 26 million human single cells spanning 45 tissues and diverse biological contexts, RegFormer achieves superior scalability and biological fidelity. Across comprehensive benchmarks, it consistently outperforms state-of-the-art single-cell foundation models (scGPT, Geneformer, scFoundation, and scBERT), delivering higher clustering accuracy, improved batch integration, and more precise cell type annotation. RegFormer also reconstructs biologically coherent GRNs, accurately models transcriptional responses to genetic perturbations, and enhances drug response prediction across cancer cell lines. By combining regulatory priors with efficient long-sequence Mamba modeling, RegFormer establishes a biologically grounded and scalable framework for single-cell representation learning, enabling deeper mechanistic insight into gene regulation and cellular state transitions.

bioinformatics↗

Iterative acylation on mature lasso peptides by widespread acetyltransferases for lipolasso production

The biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs) leverages iterative catalysis to enhance structural and biological diversity. Traditionally, iterative enzymes install multiple post-translational modifications (PTMs) on linear peptides, rather than mature RiPPs with intricate three-dimensional structures, which would require complex changes in substrate binding poses. Here, we present a prolific class of GCN5-related N-acetyltransferases (GNATs) that iteratively and consecutively acylate two Lys residues within the loop and ring motifs of lasso peptides, diverging from the typical iterative modification of linear peptides--an unprecedented function for PTM enzymes. Utilizing high-resolution cryo-electron microscopy and enzymatic reconstitution, we mapped the lasso peptide binding pocket of IatT and pinpointed key residues involved in demarcating the two distinct acetylation steps. Structure-based engineering of IatTs acetyl group recognition site expanded the cavity to accommodate longer-chain acyl groups, leading to the creation of lipolasso peptides, a novel class of ribosomal lipopeptide. This engineering strategy can be applied to any RiPP BGC encoding GNAT, facilitating the efficient diversification of rare ribosomal lipopeptides. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=95 SRC="FIGDIR/small/630886v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@1d88af9org.highwire.dtl.DTLVardef@18c1298org.highwire.dtl.DTLVardef@118b9f3org.highwire.dtl.DTLVardef@580a50_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

In vivo multiplex imaging of dynamic neurochemical networks with designed far-red dopamine sensors

Neurochemical signals like dopamine (DA) play a crucial role in a variety of brain functions through intricate interactions with other neuromodulators and intracellular signaling pathways. However, studying these complex networks has been hindered by the challenge of detecting multiple neurochemicals in vivo simultaneously. To overcome this limitation, we developed a single-protein chemigenetic DA sensor, HaloDA1.0, which combines a cpHaloTag-chemical dye approach with the G protein-coupled receptor activation-based (GRAB) strategy, providing high sensitivity for DA, sub-second response kinetics, and an extensive spectral range from far-red to near-infrared. When used together with existing green and red fluorescent neuromodulator sensors, Ca2+ indicators, cAMP sensors, and optogenetic tools, HaloDA1.0 provides high versatility for multiplex imaging in cultured neurons, brain slices, and behaving animals, facilitating in-depth studies of dynamic neurochemical networks.

neuroscience↗

A Palette of Bridged Bicycle-Strengthened Fluorophores

Organic fluorophores are the keystone of advanced biological imaging. The vast chemical space of fluorophores has been extensively explored in seek of molecules with ideal properties. However, within the current molecular constraints, there appears to be a trade-off between high brightness, robust photostability, and tunable biochemical properties. Herein we report a general strategy to systematically boost the performance of donor-acceptor-type fluorophores by leveraging SO2 and O-substituted azabicyclo[3.2.1] octane auxochromes. These bicyclic heterocycles give rise to a collection of Bridged dyes (BD) spanning the UV and visible range with top-notch quantum efficiencies, enhanced water solubility, and tunable cell-permeability. Notably, these azabicyclic fluorophores showed remarkable photostability than its tetramethyl or azatidine analogue, at the same time completely resistant to oxidative photobluing rendered by the Bredts rule. Functionalized BD dyes are tailored for applications in single-molecule imaging, super-resolution imaging (STED and SIM) in fixed or live mammalian cells and plant cells, and live zebrafish imaging or chemigenetic voltage imaging. Synergizing with advanced imaging methods, the bridge bicycle dyes represent a versatile palette for biological researches.

biophysics↗

Integrative analysis of transcriptome and metabolism reveals functional roles of redox homeostasis in low light and salt combined stress in Leymus chinensis

Soil salinity (Salt) is one of the major limiting factors of Leymus chinensis (named sheepgrass) performance and alters their primary metabolic process and gene expression. Salt stress could accelerate inhibitive effects concomitant with low light (LL-Salt). However, little is known about physiological and molecular mechanisms under such LL-Salt in sheepgrass. This study aims to uncover the key reprogrammed metabolic pathways induced by LL-Salt through an integrated analysis of transcriptome and metabolism. Plant seedlings were exposed to six combinations of light intensity (moderate light, ML, and LL) and NaCl concentrations (0, 50, and 200mM) for 20 days. Results suggest that the growth of sheepgrass seedlings was dramatically inhibited with severe lodging phenotype, especially when exposed to LL-Salt combined conditions. Activities of an antioxidant enzyme, catalase, were significantly increased in LL but significantly decreased in salt stress, leading to a reverse pattern for H2O2 in LL and salt stress. Transcriptome analysis reveals 4921 downregulated differentially expressed genes (DEGs) with carbon metabolism pathways were significantly enriched compared to light response without salt (ML_0 vs LL_0). There are 194 overlapped downregulated DEGs induced by two salt treatments (ML_50 vs ML_0 and ML_200 vs ML_0), where the carbon metabolism pathway was also significantly enriched. In terms of interactive effects of LL-Salt treatments, we found that there are 16 overlapped DEGs, including a phytochrome-interacting transcription factor 4 (PIF4) with upregulation in LL treatment while downregulation in salt treatment, which was validated by qPCR. Metabolism analysis confirmed that in carbon metabolism, the contents of seven differentially abundant metabolites (DAMs), including sucrose, were all downregulated in both LL and salt treatment. In contrast, serine and glycolate in the photorespiration pathway were downregulated in LL while upregulated in salt treatment. A photorespiration regulatory gene, glycolate oxidase expression, was confirmed by qPCR. Collectively, we found that serval antioxidant redox pathways, including photorespiration, GSG/GSSH redox, and ABA signaling, participated in response to LL and salt combined events and highlighted the roles of cellular redox homeostasis in LL-Salt response in sheepgrass.

plant biology↗

BioLLM: A Standardized Framework for Integrating and Benchmarking Single-Cell Foundation Models

The application and evaluation of single cell foundational models (scFMs) present significant challenges stemming from the heterogeneity of architectural frameworks and coding standards. To address these issues, we introduce BioLLM, a framework facilitating the integration and application of scFMs in single-cell RNA sequencing data analysis. BioLLM provides a universal interface, bridging diverse scFMs into a seamless ecosystem. By mitigating architectural disparities and coding conventions, it empowers researchers with streamlined access to scFMs. With standardized APIs and comprehensive documentation, BioLLM streamlines model switching and comparative analyses, while incorporating best practices for consistent model evaluation. Our comprehensive evaluation of scFMs revealed distinct strengths and limitations, highlighting scGPTs robust performance across all tasks, both in zero-shot and fine-tuning scenarios. Geneformer and scFoundation also demonstrated strong capabilities in gene-level tasks, benefiting from effective pretraining strategies. In contrast, scBERT underperformed relative to other models, likely attributable to its considerably smaller parameter count and the limited size of the training dataset. Ultimately, BioLLM aims to empower the scientific community to leverage the full potential of foundational models, advancing our understanding of complex biological systems through enhanced single-cell analysis.

bioinformatics↗

Time-Dependent Material Properties and Composition of the Nonhuman Primate Uterine Layers Through Gestation

The uterus is central to the establishment, maintenance, and delivery of a healthy pregnancy. Biomechanics is an important contributor to pregnancy success, and alterations to normal uterine biomechanical functions can contribute to an array of obstetric pathologies. Few studies have characterized the passive mechanical properties of the gravid human uterus, and ethical limitations have largely prevented the investigation of mid-gestation periods. To address this key knowledge gap, this study seeks to characterize the structural, compositional, and time-dependent micro-mechanical properties of the nonhuman primate (NHP) uterine layers in nonpregnancy and at three time-points in pregnancy: early 2nd, early 3rd, and late 3rd trimesters. Distinct material and compositional properties were noted across the different tissue layers, with the nonpregnant endometrium and pregnant decidua being the least stiff, most viscous, least diffusible, and most hydrated layers of the NHP uterus. Pregnancy induced notable compositional and structural changes in the decidua and myometrium but had no effect on their micro-mechanical properties. Further comparison to published human data revealed marked similarities across species, with minor differences noted for the perimetrium and nonpregnant endometrium. This work provides insights into the material properties of the NHP uterus and demonstrates the validity of NHPs as a model for studying certain aspects of human uterine biomechanics.

bioengineering↗

ATP-gated P2x7 receptor is a major channel type at type II auditory nerves and required for hearing sensitivity efferent controlling and noise protection

Hearing sensitivity and noise protection are mediated and determined by negative feedback of the cochlear efferent system. Type II auditory nerves (ANs) innervate outer hair cells (OHCs) in the cochlea and provide an input to this efferent control. However, little is known about underlying channel information. Here, we report that ATP-gated P2x7 receptor had a predominant expression at type II ANs and the synaptic areas under inner hair cells and OHCs with lateral and medial olivocochlear efferent nerves. Knockout (KO) of P2x7 increased hearing sensitivity with enhanced acoustic startle response (ASR), auditory brainstem response (ABR), and cochlear microphonics (CM) by increasing OHC electromotility, an active cochlear amplifier in mammals. P2x7 KO also increased susceptibility to noise. Middle level noise exposure could impair active cochlear mechanics resulting in permanent hearing loss in P2x7 KO mice. These data demonstrate that P2x7 receptors have a critical role in type II AN function and the cochlear efferent system to control hearing sensitivity; deficiency of P2x7 receptors can impair the cochlear efferent suppression leading to hearing oversensitivity and susceptibility to noise.

neuroscience↗

OpenExo: An Open-Source Modular Exoskeleton to Augment Human Function

While the field of wearable robotic exoskeletons is rapidly expanding, there are several barriers to entry that discourage many from pursuing research in this area, ultimately hindering growth. Chief among these are the lengthy and costly development time to get an exoskeleton from conception to implementation and the necessity for a broad set of expertise. Additionally, many exoskeletons are designed for a specific utility (e.g., ankle plantarflexor assistance) and are confined to the laboratory environment, limiting the flexibility of the designed system to adapt to answer new questions and explore new domains. To address these barriers, we present OpenExo, an open-source modular untethered exoskeleton framework that provides access to all aspects of the design process including (1) software, (2) electronics, (3) hardware, and (4) control schemes. To demonstrate the utility of this exoskeleton framework, we performed benchtop and experimental validation testing with the system across multiple configurations including (1) hip-only incline assistance, (2) ankle-only indoor and outdoor assistance, (3) hip-and-ankle load-carriage assistance, and (4) elbow-only weightlifting assistance. All aspects of the software architecture, electrical components, hip and Bowden-cable transmission designs, and control schemes are freely available for other researchers to access, use, and modify when looking to address research questions in the field of wearable exoskeletons. Our hope is that OpenExo will rapidly accelerate the development and testing of new exoskeleton designs and control schemes, while simultaneously encouraging others, including those who would have been turned away from entering the field, to explore new and unique research questions. One-Sentence SummaryWe present an open-source, open-hardware exoskeleton to aid in accelerating the growth of robotic exoskeleton research.

bioengineering↗