Browse Articles

Molecular contacts in self-assembling clusters of membrane proteins

Motivated by recent data pointing to the existence of homo-oligomeric assemblies of membrane proteins called higher-order transient structures, and their apparent role in connecting components of membrane signal pathways, we examine here by cryoelectron microscopy some of the protein–protein interactions that occur in cluster formation. Metabotropic glutamate receptors and HCN ion channels inside clusters contact their neighbors through structured extracellular and intracellular domains, respectively. Other ion channels, including Kv2.1 and Slo1, appear to form clusters through prominent intrinsically disordered sequences in the cytoplasm. These distinct modes of interaction are associated with clusters exhibiting varying degrees of compactness and order. We conclude that nature utilizes a variety of ways to form connections between membrane proteins in self-assembled clusters.

Closed-loop two-photon functional imaging in a freely moving animal

Abstract Direct measurement of neural activity in freely moving animals is essential for understanding how the brain controls and represents behaviors. Genetically encoded calcium indicators report neural activity as changes in fluorescence intensity, but brain motion confounds quantitative measurement of fluorescence. Translation, rotation, and deformation of the brain and the movements of intervening scattering or autofluorescent tissue all alter the amount of fluorescent light captured by a microscope. Compared to single-photon approaches, two-photon microscopy is less sensitive to scattering and off-target fluorescence, but more sensitive to motion, and two photon imaging has always required anchoring the microscope to the brain. We developed a closed-loop resonant axial-scanning high-speed two-photon (CRASH2p) microscope for real-time 3D motion correction in unrestrained animals, without implantation of reference markers. We complemented CRASH2p with a ‘Pong’ scanning strategy and a multi-stage registration pipeline. We performed volumetric ratiometrically corrected functional imaging in the CNS of freely moving Drosophila larvae and discovered previously unknown neural correlates of behavior.

Hundreds of grocery outlets needed across the United States to achieve walkable cities

Abstract The location of amenities in urban areas fundamentally shapes both sustainability and equity outcomes. While cities worldwide are pursuing walkable neighborhood initiatives, the practical implications of retrofitting existing urban areas remain unclear. How many new facilities are needed, and where should they be located to ensure equitable access? We analyzed supermarket access across 500 U.S. cities using an optimization approach that minimizes both average distance and inequality in its distribution. Unlike traditional methods that focus solely on reducing inequality or average distance, our approach identifies solutions that improve overall accessibility while reducing disparities. We found that 25% of cities could achieve 15-minute walking access by adding five or fewer stores in optimal locations, while more ambitious 5-minute targets would require over 100 additional stores in most cities. These findings demonstrate both the potential for strategic interventions to efficiently improve access and the substantial challenge posed by car-oriented urban development. By identifying priority areas for new facilities while considering distributional impacts, our method can inform multiple stakeholders working to create more sustainable and equitable cities - from local governments using zoning and incentives to state agencies developing funding programs and community organizations advocating for improved food access.

Photothermal-electrocatalysis interface for fuel-cell grade ammonia harvesting from the environment

Enhanced security for IoT cloud environments using EfficientNet and enhanced football team training algorithm

Evaluating the distribution and clustering of SARS-CoV-2 antibodies in dogs across the United States of America

Fundamentals of 1/f noise reduction technique based on complementary cascode switching applied to a 52 microwatts 5.2pJ/bit 100Kb/s 120 GHz receiver

Experimental investigation of CTAB modified clay on oil recovery and emulsion behavior in low salinity water flooding

Disproportionality analysis of adverse events associated with ipilimumab and nivolumab combination therapy based on FAERS database

Association between wet-bulb globe temperature with gastroesophageal reflux disease in different geographic regions in a large Taiwanese population study

Restoration and functional analysis of the SGI1 resolution system – SGI1 multimers are eliminated by the reactivated resolution

Abstract SGI1 and the related elements that are specifically mobilized by the IncA- and IncC-family plasmids are efficient agents in the dissemination of multi-resistance in Gammaproteobacteria. The In104 gene cluster responsible for multi-resistance in these genomic islands is generally integrated into the conserved SGI1 backbone, upstream of a resolvase gene, presumably by res-hunting transposition events. In this work we demonstrate that precise deletion of In104 cluster with one copy of its flanking direct repeats restores the res site belonging to the resolvase gene, leading to an active Tn3-like resolution system. The entire res site and its subsites have been identified and the resolvase activity has been demonstrated in plasmid-based recombination assays. The major effect of the reactivated resolution system seems to be the rapid elimination of SGI1 multimers in SGI1 transconjugants. It has been shown that wt SGI1-C and the resolvase-deleted SGI1ΔIn104 variant produce significantly more concatemers, which persist for longer periods in transconjugants, than SGI1ΔIn104 with a functional resolution system. High prevalence of inactivated res systems among the multidrug-resistant members of SGI1-family suggests that the ability to produce more and more stable multimers in SGI1 transconjugants may confer evolutionary advantage to these elements.

Testing the effect of host availability on endobiont diversity: proposing the single hotel hypothesis

An ABA–ROP toggle switch orchestrates xylem differentiation and cell wall patterning

The mutual antagonistic signaling of abscisic acid (ABA) and ROP GTPases highlights an intersection between stress responses and pattern formation. Previously, we have shown that signaling of ABA in the endodermis leads to protoxylem (PX) differentiation. In this study, we demonstrate that ROPs suppress PX differentiation in the roots of both Arabidopsis and tomato. Fourier transform and Shannon’s entropy show that endodermal ABA signaling controls the periodicity and overall order of PX secondary cell wall (SCW) coils in an ROP-dependent manner. Correspondingly, in the PX, GFP-ROP11 is initially dispersed and gradually becomes distributed in an oscillatory fashion with a periodicity corresponding to that of the SCW coils. Oryzalin treatments disrupt the frequency and increase the entropy of the GFP-ROP11 signal, suggesting that microtubules delimit ROP distribution. Signaling of ABA in the endodermis encourages the enlargement of metaxylem SCW pits, while ABA signaling in the stele limits this enlargement. Pit size and density are decreased in ROP mutants while ABA enhances ROP11 expression in the stele and broadens its distribution in the endodermis. Taken together, non-cell-autonomous and cell-autonomous interactions between ABA and ROPs regulate xylem differentiation and SCW patterning.

Caffeine enhances antitumor T-cell activity by suppressing kynurenine pathway in colorectal cancer

Deterministic generation of two-dimensional multi-photon cluster states

Printing photonic-based thermal barrier coatings onto metal alloy

Abstract Reflective coatings based on photonic crystals and photonic glasses are usually produced by traditional colloidal self-assembly techniques characterised by limited control over the deposition surface and lengthy processing times. The emergence of Additive Manufacturing combined with Colloidal Assembly (AMCA) has enabled fast and precise deposition of homogeneous photonic structures, whilst circumventing issues such as the undesired coffee-ring effect. However, the application of this technique was limited to flat substrates. This study investigates the AMCA of ceramic-based colloidal structures onto metallic curved surfaces, relevant to the field of thermal barrier coatings (TBCs). Our results demonstrate the homogeneous ceramic-based photonic glass coatings can be AMCA-printed on different substrates only when a conscious surface charge matching between the colloidal particles and the substrates is made. It also demonstrates the importance of controlling the contact angle of the suspension on the substrates and the printing geometry strategy, differing from traditional direct writing. We further demonstrate the versatility of this method by printing highly porous three-dimensional gadolinium zirconate structures onto curved Inconel substrates. These coatings are engineered for their use as reflective “photonic-based” thermal barrier coatings (rTBCs), capable of suppressing both radiative and conductive heat transport. The resultant AMCA-printed Gd2Zr2O7 rTBCs outperform state-of-the-art TBCs in terms of their reflectance properties and provide a reliable thermal protection to the underlying Inconel alloy, lowering its temperature by about 150 °C in a torch experiment.

Quantum phase transition in the Casten pyramid using entanglement entropy in the semi-classical approximation of IBM-2

Evaluation of oral hygiene and gingival parameters in pediatric nephrotic syndrome within an interdisciplinary care model

Distributed sliding mode control approach with adaptive spacing policy for vehicle platoons in communication interruption scenario

Bioinformatic prediction of key genes involved in pro-chondrogenic effect of fragmentated cartilage transplantation

Abstract Minced cartilage transplantation is thought to promote cartilage repair. However, the underlying mechanisms remain less well understood. In this study, we established a rat osteochondral defect model to evaluate fragment size-dependent repair efficacy, and tried to explore the mechanisms preliminarily. Herein, rats with cartilage defect were randomly divided into 3 groups. Small allogeneic cartilage fragments with fibrin glue, chunk allogeneic cartilage fragments with fibrin glue, and only fibrin glue were used to treat cartilage defects in each group, respectively. The results showed that the minced cartilage fragments had significantly improved outcomes in promoting cartilage repairing compared to chunk cartilage fragments and only fibrin glue. Notably, particulated cartilage transplantation-treat cartilage lesion had elevated inflammation. Following RNA-seq analysis on cartilage fragments and cartilage chunk identified 75 differentially expressed genes (DEGs), which include 70 up-regulated DEGs and 5 down-regulated DEGs in cartilage fragment group (CFG). Further GO enrichment and KEGG pathway analysis showed that the up-regulated DEGs in CFG were mainly involved in inflammation, cell proliferation and migration. We also found that the down-regulated DEGs in CFG had negative relationship with cell migration, proliferation and inflammation. This study suggest that cartilage fragmentation enhances repair efficacy compared to chunk cartilage transplantation, and the mechanism of pro-chondrogenic effect may be related to inflammatory stimulation.