Browse Articles

Highly selective synthesis of interlocked carbazole-based cages and their applications in photothermal seawater desalination

Milli-Tesla quantization enabled by tuneable Coulomb screening in large-angle twisted graphene

Conservation of dark CPD photolyase function in blind cavefish

Abstract DNA damage is generated by various environmental stressors and so DNA repair systems must inevitably adapt to changing environments. Photolyases represent a highly conserved class of enzymes which repair UV-induced covalent crosslinks between adjacent pyrimidine bases (CPD and 6-4 photoproducts) via photoreactivation. In the blind cavefish Phreatichthys andruzzii which has evolved for millions of years completely isolated from UV radiation and visible light, we have documented multiple polymorphisms and loss of function mutations affecting both the 6-4phr and DASHphr photolyase genes while strangely, the CPDphr gene remains highly conserved. Using loss and gain of photolyase function medaka and mammalian cell lines, we reveal a novel function for CPDphr. Specifically, it enables the light-independent repair of CPD as well as 8-OHdG, an oxidatively modified form of guanosine which are both generated under oxidative stress in the absence of UV radiation. Thereby we document selective conservation of light-independent photolyase function in blind cavefish, enabling the repair of DNA damage encountered in an extreme subterranean environment.

Semitransparent organic photovoltaics with wide geographical adaptability as sustainable smart windows

Molecular basis of human taurine transporter uptake and inhibition

Ultra-long-range optical pulling with an optical nanofibre

Gamma-band synchronization between neurons in the visual cortex is causal for effective information processing and behavior

Abstract Successful behavior relies on the brain’s ability to process selectively attended information while suppressing irrelevant information. Visual neurons show such functional flexibility by selectively responding to subsets of inputs representing attended objects while ignoring those conveying information about irrelevant objects. Several neuronal mechanisms have been proposed to explain this attention-dependent processing, yet none has been proven as a causal mechanism. One requires precise synchronization between spikes carrying relevant information and the gamma-oscillatory activity in receiving neurons. To investigate its causal relevance, we electrically evoked single volleys of spikes in area V2 of two male macaque monkeys performing a selective-attention task and recorded neuronal activity in downstream area V4. Strongly depending on the γ-phase, when these additional spikes arrived in V4, they impaired monkeys’ performance and evoked a spiking response. This establishes the causal relevance of subtle changes in spike timing, specifically by phase synchronization, for neuronal mechanisms serving cognitive processes.

Increasing certainty in systems biology models using Bayesian multimodel inference

Abstract Mathematical models are indispensable for studying the architecture and behavior of intracellular signaling networks. It is common to develop models using phenomenological approximations due to the difficulty of fully observing the intermediate steps in intracellular signaling pathways. Thus, multiple models can be built to represent the same pathway. This opens up challenges for model selection and decreases certainty in predictions. Here, we investigate Bayesian multimodel inference (MMI) as an approach to increase certainty in systems biology predictions, which becomes relevant when one wants to leverage a set of potentially incomplete models. Using existing models of the extracellular-regulated kinase (ERK) pathway, we show that MMI successfully combines models and yields predictors robust to model set changes and data uncertainties. We then use MMI to identify possible mechanisms of experimentally measured subcellular location-specific ERK activity. This work highlights MMI as a disciplined approach to increasing the certainty of intracellular signaling activity predictions.

Atomic-scale visualization of strain-tailored noncollinear spin textures in an antiferromagnetic ultrathin film

In vivo antimicrobial activity of engineered mesoporous silica nanoparticles targeting intracellular mycobacteria

Abstract Treatments of Mycobacterium marinum, a common non-tuberculous mycobacterium associated with cutaneous infections are very challenging, emphasizing the development of new therapeutic approaches. Here we report the functionalization of mesoporous silica nanoparticles (MSN) with a series of triphenylphosphonium (TPP) substituents, which endowed them with affinity towards the surface of M. marinum in vitro, as well as within infected THP-1 cells. The presence of these nanoparticles at the bacterial surface prevents their uptake by human macrophages and dendritic cells. When loaded with doxycycline, the nanosystem exerts a potent anti-bacterial effect in planktonic cultures, biofilms, and in M. marinum-infected macrophages. Strikingly, in the M. marinum/zebrafish infection model, the doxycycline-loaded nanoparticles are associated with a pronounced decrease in the bacterial burden and a high embryo survival rate. These results disclose the proposed MSN nanosystems as a promising alternative for the treatment of M. marinum infection and, presumably, against a broader range of mycobacterial infections.

Mechanically robust eutectogels enabled by precisely engineered crystalline domains

Mid-Holocene extreme precipitation in the Tibesti, Central Sahara

Abstract During the early and mid Holocene deep lakes existed in the Tibesti volcanic complex, the highest mountain in the Sahara, but it is still unclear why they formed. Here, we combine sedimentary data analyses, high-resolution climate modelling and water balance modelling to provide a quantitative and differentiated estimate of the mid-Holocene water balance of the Trou au Natron (Doon Orei) and Era Kohor crater lakes and to discuss the underlying atmospheric circulation. During the mid-Holocene, the Tibesti received at least an order of magnitude more precipitation than the surrounding plains due to strong orographic uplift of moist air masses, which were surprisingly brought in by north-easterly winds from the Mediterranean, not by the stronger West African monsoon from the south. This may explain differences in the water levels between the Trou au Natron in the north-western part of the Tibesti and the Era Kohor in the south-eastern, leeward part. Our analysis demonstrates the importance of orographic precipitation for evaluating the hydroclimate of the central part of the Sahara – a factor grossly underestimated in the global climate models commonly used for palaeo and future climate simulations.

Computationally unmasking each fatty acyl C=C position in complex lipids by routine LC-MS/MS lipidomics

Abstract Identifying carbon-carbon double bond (C=C) positions in complex lipids is essential for elucidating physiological and pathological processes. Currently, this is impossible in high-throughput analyses of native lipids without specialized instrumentation that compromises ion yields. Here, we demonstrate automated, chain-specific identification of C=C positions in complex lipids based on the retention time derived from routine reverse-phase chromatography tandem mass spectrometry (RPLC-MS/MS). We introduce LC=CL, a computational solution that utilizes a comprehensive database capturing the elution profile of more than 2400 complex lipid species identified in RAW264.7 macrophages, including 1145 newly reported compounds. Using machine learning, LC=CL provides precise and automated C=C position assignments, adaptable to any suitable chromatographic condition. To illustrate the power of LC=CL, we re-evaluated previously published data and discovered new C=C position-dependent specificity of cytosolic phospholipase A2 (cPLA2). Accordingly, C=C position information is now readily accessible for large-scale high-throughput studies with any MS/MS instrumentation and ion activation method.

AI-assisted cervical cytology precancerous screening for high-risk population in resource-limited regions using a compact microscope

Interface-controlled uniaxial in-plane ferroelectricity in Hf0.5Zr0.5O2(100) epitaxial thin films

In situ molecular weaving of ionic polymers into metal-organic frameworks for radioactive anion capture

Abstract Encapsulation of polymer chains into nanochannels of metal-organic frameworks (MOFs) to construct polymer-MOF hybrid materials can retain the desired properties of two disparate materials. However, the facile fabrication of such hybrids remains challenging, given the difficulty in unraveling entanglement of polymer chains and constraining them into ordered conformations. Herein, we introduce an in situ molecular weaving strategy to construct ionic polymer-MOF hybrid materials, employing shear forces and coordination interactions to untangle cationic polymer chains and guide their realignment within MOF nanochannels during framework formation. Notably, this realignment promotes uniform polymer distribution and exposes more anion-exchange sites. The resulting hybrids capture ReO4 ¯ (a nonradioactive surrogate of 99TcO4 ¯) with a capacity of 438 mg g-1 and reach adsorption equilibrium within 20 min. Characterization and theoretical calculations reveal that the hydrophobic pores in the hybrid materials confer strong affinity toward less hydrated 99TcO4 ¯ anions, thereby enhancing their selectivity over competing anions.

Mechanisms and interventions promoting healthy frontostriatal dynamics in obsessive-compulsive disorder

Abstract Changes in the frontostriatal system activity support individuals’ perseverance in distressful thoughts and rigid, repetitive behaviours that define obsessive-compulsive disorder (OCD). Converging evidence from preclinical and clinical work suggests that OCD maps onto a functional imbalance in the ventral and dorsal frontostriatal circuits. However, the neural mechanisms supporting these dysregulations remain elusive, their association with symptom severity is unclear, and therapeutic interventions are limited. To address these gaps, we combined neuroimaging and behavioural data from individuals with OCD and controls with computational modelling. We found that bidirectionally decreasing spontaneous neural coupling in the ventromedial circuit while concurrently increasing dorsolateral cortico-striatal coupling delivered the highest functional improvements in OCD. The analysis of longitudinal changes in obsessions and compulsions with respect to modelled neural interventions supported our predictions. By highlighting behaviourally meaningful neural mechanisms hidden from traditional neuroimaging analysis, this study advances knowledge on the neural basis of OCD and provides new therapeutic targets for obsessions and compulsions.

Colour segmentation of printed fabrics by integrating adaptive neural network and density peak clustering algorithm

With the development of computer vision and image processing technology, color segmentation of printed fabrics has gradually become a key task in the textile industry. However, the existing methods often face the problems of low segmentation accuracy and poor computational efficiency when dealing with high complexity patterns and similar colors. To address the above problems, a new color segmentation algorithm for printed fabrics is proposed by integrating the self-organizing mapping network (SOM) in adaptive neural network and the density peak clustering algorithm. The method achieves topological mapping learning of color features through SOM, and then uses DPC for density-driven fine clustering division, which effectively improves the accuracy and stability of color segmentation. The experimental results show that the proposed method shortens the execution time by nearly 40% compared with the self-organized mapping network, and the average color difference (ΔE) of each region after color segmentation is as low as 0.7, which is significantly better than other algorithms. Meanwhile, in the detection of the four types of printed fabric samples, the obtained average color value is up to 87.49 (the higher the 0–100 score value indicates that the color is more significant), and the smallest standard deviation is 2.18 (the smaller the value indicates that the color segmentation is more centralized), which further verifies the comprehensive advantages of the algorithm in terms of segmentation accuracy and stability. In conclusion, the proposed method provides an effective reference for improving the quality and efficiency of color segmentation of printed fabrics.

Observation of dendrite formation at Li metal-electrolyte interface by a machine-learning enhanced constant potential framework

Differential microRNA profiling of the Marshallese population in Arkansas reveals a higher association with chronic diseases

The Marshallese communities face disproportionately high prevalence of chronic diseases, including diabetes, obesity, cardiovascular disease, and inflammatory conditions. Differences in miRNA expression may contribute to investigate the potential risk of chronic diseases in Marshallese people. In this study, we used RNA isolated from blood samples of Marshallese participants that resides in Arkansas to perform miRNA expression profiling and differential expression analysis. Specifically, blood samples were collected from 47 Marshallese participants after obtaining written informed consent and were subjected to Illumina-based next-generation RNA sequencing. Using the miRBase database, we identified the miRNAs that were most significantly expressed based on log2 fold change values, applying a Bonferroni-corrected P-value threshold of < 0.01. We found that a total of 63 human miRNAs were differentially expressed in the Marshallese subjects, with 52 miRNAs significantly upregulated and 11 miRNAs downregulated in males compared with females. Notably, 2 miRNA families, hsa-miR-548 and hsa-let-7, were significantly upregulated in the Marshallese population and are known to play important roles in regulating inflammatory responses. Further analysis revealed the 25 miRNAs that had the largest significant difference in expression with a cutoff of 1.5 when comparing males with females. Among these, we observed that 7 miRNAs were upregulated, and 18 miRNAs were downregulated by greater than 1.5 log2 fold change in males versus females. Interestingly, upregulated expression of hsa-miR-548k in males and hsa-miR-496 in females were both associated with diabetes mellitus. Diabetes remains a major health concern in the Marshallese community and may accelerate comorbidities related to cardiovascular conditions and cognitive decline. Therefore, the specific roles of these miRNAs in relation to these health issues warrant further investigation.