326 research outputs found
Gene Expression Changes Associated with the Airway Wall Response to Injury
Understanding the way in which the airway heals in response to injury is fundamental to dissecting the mechanisms underlying airway disease pathology. As only limited data is available in relation to the in vivo characterisation of the molecular features of repair in the airway we sought to characterise the dynamic changes in gene expression that are associated with the early response to physical injury in the airway wall.We profiled gene expression changes in the airway wall using a large animal model of physical injury comprising bronchial brush biopsy in anaesthetised sheep. The experimental design featured sequential studies in the same animals over the course of a week and yielded data relating to the response at 6 hours, and 1, 3 and 7 days after injury. Notable features of the transcriptional response included the early and sustained preponderance of down-regulated genes associated with angiogenesis and immune cell activation, selection and differentiation. Later features of the response included the up-regulation of cell cycle genes at d1 and d3, and the latter pronounced up-regulation of extracellular matrix-related genes at d3 and d7.It is possible to follow the airway wall response to physical injury in the same animal over the course of time. Transcriptional changes featured coordinate expression of functionally related genes in a reproducible manner both within and between animals. This characterisation will provide a foundation against which to assess the perturbations that accompany airway disease pathologies of comparative relevance
New genus of the tribe Ceutorhynchini (Coleoptera: Curculionidae) from the late Oligocene of Enspel, southwestern Germany, with a remark on the role of weevils in the ancient food web
The new weevil genus Igneonasus gen. nov. (type species: I. rudolphi sp. nov.) of the tribe
Ceutorhynchini (Curculionidae: Conoderinae: Ceutorhynchitae) is described
from the late Oligocene of Fossillagerstätte Enspel, Germany. The new
genus differs from the similar genus Stenocarus Thomson, 1859 in the anterior margin
of the pronotum, which is not raised, a pronotum without tubercles on the
sides, and a femur without teeth. This weevil is the largest representative
of this supertribe and the first fossil Curculionidae species described from
the paleolake Enspel. In this ancient ecosystem, weevils were at least sometimes
an important food resource for the cyprinid fish Palaeorutilus enspelensis.</p
Surficial Functionalization of Monolithic Carbon Electrode via Femtosecond Laser Treatment
Carbon materials are promising to fulfill the worldwide need for advanced materials in many areas, particularly in electrochemical applications. However, achieving both high conductivity and surface functionalization in carbon electrodes remains a significant challenge. Herein, a scalable, sustainable, binder-free carbon disc electrode is developed in the desired size and shape. Subsequent femtosecond laser treatment introduces surface functionalization with pyrrolic and pyridinic nitrogen species (up to 12.6 at%, as determined by X-ray photoelectron spectroscopy) while preserving the bulk crystallinity and conductivity of the electrode. The laser-treated surfaces exhibit superhydrophilicity (water contact angle of 0°) and oleophilicity (0° for n-heptane, 25° for n-heptadecane), enabling enhanced interaction with electrolytes and anchoring of metal species like iron ions. Electrochemical impedance spectroscopy confirms minimal resistance (≤10 Ω) in 0.1M KOH, even after functionalization. The functionalized electrodes demonstrate improved stability in oxygen evolution reaction tests, with laser-treated samples showing 300-500 mV higher activity than untreated counterparts when Fe-impregnated. This work establishes a simple, industrial-scale method for creating multifunctional carbon electrodes with tailored surface properties, bridging the gap between material sustainability and electrochemical performance
Quantitative insights into the cyanobacterial cell economy
© Zavřel et al. Phototrophic microorganisms are promising resources for green biotechnology. Compared to heterotrophic microorganisms, however, the cellular economy of phototrophic growth is still insufficiently understood. We provide a quantitative analysis of light-limited, light-saturated, and light-inhibited growth of the cyanobacterium Synechocystis sp. PCC 6803 using a reproducible cultivation setup. We report key physiological parameters, including growth rate, cell size, and photosynthetic activity over a wide range of light intensities. Intracellular proteins were quantified to monitor proteome allocation as a function of growth rate. Among other physiological acclimations, we identify an upregulation of the translational machinery and downregulation of light harvesting components with increasing light intensity and growth rate. The resulting growth laws are discussed in the context of a coarse-grained model of phototrophic growth and available data obtained by a comprehensive literature search. Our insights into quantitative aspects of cyanobacterial acclimations to different growth rates have implications to understand and optimize photosynthetic productivity
RISnet: A Domain-Knowledge Driven Neural Network Architecture for RIS Optimization with Mutual Coupling and Partial CSI
Multiple access techniques are cornerstones of wireless communications. Their
performance depends on the channel properties, which can be improved by
reconfigurable intelligent surfaces (RISs). In this work, we jointly optimize
MA precoding at the base station (BS) and RIS configuration. We tackle
difficulties of mutual coupling between RIS elements, scalability to more than
1000 RIS elements, and channel estimation. We first derive an RIS-assisted
channel model considering mutual coupling, then propose an unsupervised machine
learning (ML) approach to optimize the RIS. In particular, we design a
dedicated neural network (NN) architecture RISnet with good scalability and
desired symmetry. Moreover, we combine ML-enabled RIS configuration and
analytical precoding at BS since there exist analytical precoding schemes.
Furthermore, we propose another variant of RISnet, which requires the channel
state information (CSI) of a small portion of RIS elements (in this work, 16
out of 1296 elements) if the channel comprises a few specular propagation
paths. More generally, this work is an early contribution to combine ML
technique and domain knowledge in communication for NN architecture design.
Compared to generic ML, the problem-specific ML can achieve higher performance,
lower complexity and symmetry.Comment: 13 pages, 16 figure
Fungi hijack a ubiquitous plant apoplastic endoglucanase to release a ROS scavenging beta-glucan decasaccharide to subvert immune responses
Plant pathogenic and beneficial fungi have evolved several strategies to evade immunity and cope with host-derived hydrolytic enzymes and oxidative stress in the apoplast, the extracellular space of plant tissues. Fungal hyphae are surrounded by an inner insoluble cell wall layer and an outer soluble extracellular polysaccharide (EPS) matrix. Here, we show by proteomics and glycomics that these two layers have distinct protein and carbohydrate signatures, and hence likely have different biological functions. The barley (Hordeum vulgare) β-1,3-endoglucanase HvBGLUII, which belongs to the widely distributed apoplastic glycoside hydrolase 17 family (GH17), releases a conserved β-1,3;1,6-glucan decasaccharide (β-GD) from the EPS matrices of fungi with different lifestyles and taxonomic positions. This low molecular weight β-GD does not activate plant immunity, is resilient to further enzymatic hydrolysis by β-1,3-endoglucanases due to the presence of three β-1,6-linked glucose branches and can scavenge reactive oxygen species. Exogenous application of β-GD leads to enhanced fungal colonization in barley, confirming its role in the fungal counter-defensive strategy to subvert host immunity. Our data highlight the hitherto undescribed capacity of this often-overlooked EPS matrix from plant-associated fungi to act as an outer protective barrier important for fungal accommodation within the hostile environment at the apoplastic plant–microbe interface
CuCo2S4 deposited on TiO2: Controlling the pH Value Boosts Photocatalytic Hydrogen Evolution
Metallic spinel‐type CuCo2S4 nanoparticles were deposited on nanocrystalline TiO2 (P25®), forming heterostructure nanocomposites. The nanocomposites were characterized in detail by X‐ray powder diffraction (XRD), high‐resolution transmission electron microscopy (HRTEM), nitrogen sorption (BET) and UV/Vis spectroscopy. Variation of the CuCo2S4:TiO2 ratio to an optimum value generated a catalyst which shows a very high photocatalytic H2 production rate at neutral pH of 32.3 µmol/h (0.72 mL h–1), which is much larger than for pure TiO2 (traces of H2). The catalyst exhibits an extraordinary long‐term stability and after 70 h irradiation time about 2 mmol H2 were generated. An increased light absorption and an efficient charge separation for the sample with the optimal CuCo2S4:TiO2 ratio is most probably responsible for the high catalytic activity
Mitochondrial calcium uniporter complex controls T-cell-mediated immune responses
T-cell receptor (TCR)-induced Ca2+ signals are essential for T-cell activation and function. In this context, mitochondria play an important role and take up Ca2+ to support elevated bioenergetic demands. However, the functional relevance of the mitochondrial-Ca2+-uniporter (MCU) complex in T-cells was not fully understood. Here, we demonstrate that TCR activation causes rapid mitochondrial Ca2+ (mCa2+) uptake in primary naive and effector human CD4+ T-cells. Compared to naive T-cells, effector T-cells display elevated mCa2+ and increased bioenergetic and metabolic output. Transcriptome and proteome analyses reveal molecular determinants involved in the TCR-induced functional reprogramming and identify signalling pathways and cellular functions regulated by MCU. Knockdown of MCUa (MCUaKD), diminishes mCa2+ uptake, mitochondrial respiration and ATP production, as well as T-cell migration and cytokine secretion. Moreover, MCUaKD in rat CD4+ T-cells suppresses autoimmune responses in an experimental autoimmune encephalomyelitis (EAE) multiple sclerosis model. In summary, we demonstrate that mCa2+ uptake through MCU is essential for proper T-cell function and has a crucial role in autoimmunity. T-cell specific MCU inhibition is thus a potential tool for targeting autoimmune disorders
RISnet: A Domain-Knowledge Driven Neural Network Architecture for RIS Optimization with Mutual Coupling and Partial CSI
Space-division multiple access (SDMA) plays an important role in modern wireless communications. Its performance depends on the channel properties, which can be improved by reconfigurable intelligent surfaces (RISs). In this work, we jointly optimize SDMA precoding at the base station (BS) and RIS configuration. We tackle difficulties of mutual coupling between RIS elements, scalability to more than 1000 RIS elements, and high requirement for channel estimation. We first derive an RIS-assisted channel model considering mutual coupling, then propose an unsupervised machine learning (ML) approach to optimize the RIS with a dedicated neural network (NN) architecture RISnet, which has good scalability, desired permutation-invariance, and a low requirement for channel estimation. Moreover, we leverage existing high-performance analytical precoding scheme to propose a hybrid solution of ML-enabled RIS configuration and analytical precoding at BS. More generally, this work is an early contribution to combine ML technique and domain knowledge in communication for NN architecture design. Compared to generic ML, the problem-specific ML can achieve higher performance, lower complexity and permutation-invariance
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