FDX1-dependent and independent mechanisms of elesclomol-mediated intracellular copper delivery.

Recent studies have uncovered the therapeutic potential of elesclomol (ES), a copper-ionophore, for copper deficiency disorders. However, we currently do not understand the mechanism by which copper brought into cells as ES-Cu(II) is released and delivered to cuproenzymes present in different subcellular compartments. Here, we have utilized a combination of genetic, biochemical, and cell-biological approaches to demonstrate that intracellular release of copper from ES occurs inside and outside of mitochondria. The mitochondrial matrix reductase, FDX1, catalyzes the reduction of ES-Cu(II) to Cu(I), releasing it into mitochondria where it is bioavailable for the metalation of mitochondrial cuproenzyme- cytochrome c oxidase. Consistently, ES fails to rescue cytochrome c oxidase abundance and activity in copper-deficient cells lacking FDX1. In the absence of FDX1, the ES-dependent increase in cellular copper is attenuated but not abolished. Thus, ES-mediated copper delivery to nonmitochondrial cuproproteins continues even in the absence of FDX1, suggesting alternate mechanism(s) of copper release. Importantly, we demonstrate that this mechanism of copper transport by ES is distinct from other clinically used copper-transporting drugs. Our study uncovers a unique mode of intracellular copper delivery by ES and may further aid in repurposing this anticancer drug for copper deficiency disorders.

From [2Mn2S] Diamond Cores to Butterfly Rhombs: Transformations That Highlight Alternating Peptide Binding Sites.

Thiocarboxamide chelates are known to assemble [2Mn2S] diamond core complexes via µ-S bridges that connect two MnI(CO)3 fragments. These can exist as syn- and anti-isomers and interconvert via 16-electron, monomeric intermediates. Herein, we demonstrate that reduction of such Mn2 derivatives leads to a loss of one thiocarboxamide ligand and a switch of ligand binding mode from an O- to N-donor of the amide group, yielding a dianionic butterfly rhomb with a short Mn0-Mn0 distance, 2.52 Å. Structural and chemical analyses suggest that reduction of the Mn(I) centers is dependent on the protonation state of the amide-H, as total deprotonation followed by reduction does not result in the reduction of the Mn2 core. Partial deprotonation followed by reduction suggests a pathway that involves monomeric Mn(CO)3(S-O) and Mn(CO)3(S-N) intermediates. Ligand modifications to tertiary amides that remove the possibility of amide-H reduction led to complexes that preserve the [2Mn2S] diamond core during chemical reduction. Further comparison with the tethered system, linking the Mn(CO)3(S-O) sites together, suggests that dimer dissociation is necessary for the overall reductive transformation. These results highlight organomanganese carbonyl chemistry to establish illustrations of peptide fragment binding modes in the uptake of low-valent metal carbonyls related to binuclear active sites of biocatalysts.

A modification of normalized difference drought index to enhance drought assessment using remotely sensed imagery.

Drought is one of the common natural disasters with a wide range of occurrences in terms of space and time, and with varying levels of severity, that may result in economic damage and health issues to humans. This study focuses on assessing drought severity in the Central Highlands of Vietnam based on ground meteorological stations and multispectral remote sensing data. A Modification of the Normalized Difference Drought Index (MNDDI) was developed to enhance the effectiveness of remote sensing indices in the drought assessment. Results indicate that MNDDI outperforms Normalized Difference Drought Index and other investigated indicators, such as Normalized Difference Vegetation Index, Normalized Difference Latent Heat Index, and Normalized Difference Water Index, in representing the Earth's surface response to drought events. Correlations ranging from 0.85 to 0.63 were identified between MNDDI and various time scales of the commonly used meteorological drought indicator, namely the Standardized Precipitation Index, during the drought year of 2015. This work also reveals the superiority of MNDDI in portraying the response of land cover types to drought situations. The finding of a severe drought phenomenon in critical agricultural zones is highly consistent with the report from the Ministry of Agriculture and Rural Development of Vietnam. This study contributes valuable insights to the preliminary assessment of drought through remote sensing data, offering a foundation for precise drought outlooks and effective risk management strategies.

Astrocytic FoxO1 in the hypothalamus regulates metabolic homeostasis by coordinating neuropeptide Y neuron activity.

The forkhead box transcription factor O1 (FoxO1) is expressed ubiquitously throughout the central nervous system, including in astrocytes, the most prevalent glial cell type in the brain. While the role of FoxO1 in hypothalamic neurons in controlling food intake and energy balance is well-established, the contribution of astrocytic FoxO1 in regulating energy homeostasis has not yet been determined. In the current study, we demonstrate the essential role of hypothalamic astrocytic FoxO1 in maintaining normal neuronal activity in the hypothalamus and whole-body glucose metabolism. Inhibition of FoxO1 function in hypothalamic astrocytes shifts the cellular metabolism from glycolysis to oxidative phosphorylation, enhancing astrocyte ATP production and release meanwhile decreasing astrocytic export of lactate. As a result, specific deletion of astrocytic FoxO1, particularly in the hypothalamus, causes a hyperactivation of hypothalamic neuropeptide Y neurons, which leads to an increase in acute feeding and impaired glucose regulation and ultimately results in diet-induced obesity and systemic glucose dyshomeostasis.

Local magnetic delivery of adeno-associated virus AAV2(quad Y-F)-mediated BDNF gene therapy restores hearing after noise injury.

Moderate noise exposure may cause acute loss of cochlear synapses without affecting the cochlear hair cells and hearing threshold; thus, it remains "hidden" to standard clinical tests. This cochlear synaptopathy is one of the main pathologies of noise-induced hearing loss (NIHL). There is no effective treatment for NIHL, mainly because of the lack of a proper drug-delivery technique. We hypothesized that local magnetic delivery of gene therapy into the inner ear could be beneficial for NIHL. In this study, we used superparamagnetic iron oxide nanoparticles (SPIONs) and a recombinant adeno-associated virus (AAV) vector (AAV2(quad Y-F)) to deliver brain-derived neurotrophic factor (BDNF) gene therapy into the rat inner ear via minimally invasive magnetic targeting. We found that the magnetic targeting effectively accumulates and distributes the SPION-tagged AAV2(quad Y-F)-BDNF vector into the inner ear. We also found that AAV2(quad Y-F) efficiently transfects cochlear hair cells and enhances BDNF gene expression. Enhanced BDNF gene expression substantially recovers noise-induced BDNF gene downregulation, auditory brainstem response (ABR) wave I amplitude reduction, and synapse loss. These results suggest that magnetic targeting of AAV2(quad Y-F)-mediated BDNF gene therapy could reverse cochlear synaptopathy after NIHL.

Surface Acoustic Wave Propagation of GaN/Sapphire Integrated with a Gold Guiding Layer.

Gallium nitride (GaN), widely known as a wide bandgap semiconductor material, has been mostly employed in high power devices, light emitting diodes (LED), and optoelectronic applications. However, it could be exploited differently due to its piezoelectric properties, such as its higher SAW velocity and strong electromechanical coupling. In this study, we investigated the affect of the presence of a guiding layer made from titanium/gold on the surface acoustic wave propagation of the GaN/sapphire substrate. By fixing the minimum thickness of the guiding layer at 200 nm, we could observe a slight frequency shift compared to the sample without a guiding layer, with the presence of different types of surface mode waves (Rayleigh and Sezawa). This thin guiding layer could be efficient in transforming the propagation modes, acting as a sensing layer for the binding of biomolecules to the gold layer, and influencing the output signal in terms of frequency or velocity. The proposed GaN/sapphire device integrated with a guiding layer could possibly be used as a biosensor and in wireless telecommunication applications.

Ultra-Deep Sequencing of Plasma-Circulating DNA for the Detection of Tumor- Derived Mutations in Patients with Nonmetastatic Colorectal Cancer.

Identification of tumor-derived mutation (TDM) in liquid biopsies (LB), especially in early-stage patients, faces several challenges, including low variant-allele frequencies, interference by white blood cell (WBC)-derived mutations (WDM), benign somatic mutations and tumor heterogeneity. Here, we addressed the above-mentioned challenges in a cohort of 50 nonmetastatic colorectal cancer patients, via a workflow involving parallel sequencing of paired WBC- and tumor-gDNA. After excluding potential false positive mutations, we detected at least one TDM in LB of 56% (28/50) of patients, with the majority showing low-patient coverage, except for one TDM mapped to KMT2D that recurred in 30% (15/30) of patients.

H2 S Dosimetry by CuO: Towards Stable Sensors by Unravelling the Underlying Solid-State Chemistry.

The precise detection of the toxic gas H2 S requires reliable sensitivity and specificity of sensors even at minute concentrations of as low as 10 ppm, the value corresponding to typical exposure limits. CuO can be used for H2 S dosimetry, based on the formation of conductive CuS and the concomitant significant increase in conductance. In theory, at elevated temperature the reaction is reversed and CuO is formed, ideally enabling repeated and long-term use of one sensor. Yet, the performance of CuO tends to drop upon cycling. Utilizing defined CuO nanorods we thoroughly elucidated the associated detrimental chemical changes directly on the sensors, by Raman and electron microscopy analysis of each step during sensing (CuO→CuS) and regeneration (CuS→CuO) cycles. We find the decrease in the sensing performance is mainly caused by the irreversible formation of CuSO4 during regeneration. The findings allowed us to develop strategies to reduce CuSO4 formation and thus to substantially maintain the sensing stability even for repeated cycles. We achieved CuO-based dosimeters possessing a response time of a few minutes only, even for 10 ppm H2 S, and prolonged life-time.

Genetic analysis using targeted exome sequencing of 53 Vietnamese children with developmental and epileptic encephalopathies.

Developmental and epileptic encephalopathies (DEE) refers to a group of rare and severe neurodevelopmental disorders where genetic etiologies can play a major role. This study aimed to elucidate the genetic etiologies of a cohort of 53 Vietnamese patients with DEE. All patients were classified into known electroclinical syndromes where possible. Exome sequencing (ES) followed by a targeted analysis on 294 DEE-related genes was then performed. Patients with identified causative variants were followed for 6 months to determine the impact of genetic testing on their treatment. The diagnostic yield was 38.0% (20/53), which was significantly higher in the earlier onset group (<12 months) than in the later onset group (≥12 months). The 19 identified variants belonged to 11 genes with various cellular functions. Genes encoding ion channels especially sodium voltage-gated channel were the most frequently involved. Most variants were missense variants and located in key protein functional domains. Four variants were novel and four had been reported previously but in different phenotypes. Within 6 months of further follow-up, treatment changes were applied for six patients based on the identified disease-causing variants, with five patients showing a positive impact. This is the first study in Vietnam to analyze the genetics of DEE. This study confirms the strong involvement of genetic etiologies in DEE, especially early onset DEE. The study also contributes to clarify the genotype-phenotype correlations of DEE and highlights the efficacy of targeted ES in the diagnosis and treatment of DEE.

Temporal Associations Between Daytime Napping and Nocturnal Sleep: An Exploration of Random Slopes.

BACKGROUND: Restricting daytime naps is a common sleep hygiene recommendation to improve nocturnal sleep, but research on whether napping is related to sleep is mixed. The current literature is limited in that day level, bidirectional associations have not been tested in college students, and existing studies have not sufficiently examined the role of individual differences in these daily associations. PURPOSE: The current study addressed these limitations by assessing the temporal associations between self-reported daytime nap duration and objectively assessed nocturnal sleep, and whether these associations were moderated by chronotype or nap frequency, in college students. METHODS: Participants (N = 384) self-reported nap duration and wore an actiwatch to measure nocturnal sleep for 14 consecutive days and nights. Mixed linear models were used to test the daily associations between daytime nap duration and total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), and wake after sleep onset (WASO). In addition, random slope modeling was used to test whether these associations significantly varied between participants. RESULTS: Longer nap duration was significantly associated with greater WASO, lower SE, and longer SOL. Shorter TST, shorter WASO, and greater SE were related to longer next-day nap duration. CONCLUSIONS: There were several significant associations between daytime napping and nocturnal sleep, and nap frequency significantly moderated the association between TST and next-day nap duration. Future research should test daily and contextual moderators of daytime napping and nocturnal sleep, which could refine sleep hygiene efforts by identifying individuals for whom recommendations would be most helpful.

Chirality-Guided Isomerization of Mn2S2 Diamond Core Complexes: A Mechanistic Study.

Occasioned by the discovery of a ligand transfer from M(N2S2) to MnI in Mn(CO)5Br, the resulting H2N2S2 ligand-tethered dimanganese complex, (µ4-N,N'-ethylenebis(mercaptoacetamide))[Mn2(CO)6], was found to have myriad analogues of the type (µ-S-E)2[Mn2(CO)6], making up an under-studied class containing Mn2S2 rhombs. The attempt to synthesize a nontethered version resulted in a solid-state structure in an anti-conformation. However, a direct comparison of the Fourier-transform infrared spectra of the tethered versus nontethered complexes in combination with theoretical frequency calculation suggested the coexistence of syn- and anti-isomers and their interconversion in solution. Analysis of the syn- versus anti-version of the dimanganese components led to the understanding that whereas the anti-form exists as centrosymmetric RS isomers, the syn-form is restricted by C2 symmetry to be either RR or SS. Molecular scrambling experiments indicated monomeric, pentacoordinate, 16-e- (S-O)Mn(CO)3 intermediates with lifetimes sufficiently long to sample R and S monomers. Density functional theory analysis of the mechanistic pathway and a kinetic study corroborated that the proposed isomerization involves the cleavage and reformation of the dimeric structures.

De novo homozygous variant of the SCN1A gene in a patient with severe Dravet syndrome complicated by acute encephalopathy.

Variants in the SCN1A gene have been identified in epilepsy patients with widely variable phenotypes and they are generally heterozygous. Here, we report a homozygous missense variant, NM_001165963.4: c.4319C>T (p.Ala1440Val), in the SCN1A gene which seemed to occur de novo together with a gene conversion event. It's highly possible that this variant, although located in a critical functional domain of protein Nav1.1, depending on the nature of the amino acid substitution, may not cause the complete loss of protein function. And the accumulated effect by having this variant on both alleles results in a Dravet syndrome phenotype which is more severe than average. This first report of a de novo homozygous variant in the SCN1A gene, therefore, provides a clear illustration of a complex genotype-phenotype relationship.

Neural correlates of visual stimulus encoding and verbal working memory differ between cochlear implant users and normal-hearing controls.

A common concern for individuals with severe-to-profound hearing loss fitted with cochlear implants (CIs) is difficulty following conversations in noisy environments. Recent work has suggested that these difficulties are related to individual differences in brain function, including verbal working memory and the degree of cross-modal reorganization of auditory areas for visual processing. However, the neural basis for these relationships is not fully understood. Here, we investigated neural correlates of visual verbal working memory and sensory plasticity in 14 CI users and age-matched normal-hearing (NH) controls. While we recorded the high-density electroencephalogram (EEG), participants completed a modified Sternberg visual working memory task where sets of letters and numbers were presented visually and then recalled at a later time. Results suggested that CI users had comparable behavioural working memory performance compared with NH. However, CI users had more pronounced neural activity during visual stimulus encoding, including stronger visual-evoked activity in auditory and visual cortices, larger modulations of neural oscillations and increased frontotemporal connectivity. In contrast, during memory retention of the characters, CI users had descriptively weaker neural oscillations and significantly lower frontotemporal connectivity. We interpret the differences in neural correlates of visual stimulus processing in CI users through the lens of cross-modal and intramodal plasticity.

Expression of genes involved in exopolysaccharide synthesis in Lactiplantibacillus plantarum VAL6 under environmental stresses.

Environmental factors can alter exopolysaccharide biosynthesis in lactic acid bacteria (LAB). To further clarify this potential relationship, the mRNA expression of genes involved in exopolysaccharide synthesis such as glmU, pgmB1, cps4E, cps4F, cps4J, and cps4H in Lactiplantibacillus plantarum VAL6 under different conditions including temperature, pH, sodium chloride (NaCl), and carbon dioxide (CO2) intensification culture was studied. The transcriptomic data revealed that the exposure of L. plantarum VAL6 at pH 3 increased the expression level of cps4H but decreased the expression levels of pgmB1 and cps4E. Under pH 8, cps4F and cps4E were significantly upregulated, whereas pgmB1 was downregulated. Similarly, the expression levels of cps4F, cps4E, and cps4J increased sharply under stresses at 42 or 47 °C. In the case of NaCl stress, glmU, pgmB1, cps4J, and cps4H were downregulated in exposure to NaCl at 7 and 10% concentrations while cps4E and cps4F were upregulated at 1 h of 10%-NaCl treatment and at 5 h of 4%-NaCl treatment. Remarkably, CO2 intensification culture stimulated the expression of all tested genes. In addition, simultaneous changes in expression of cps4E and cps4F under environmental challenges may elicit the possibility of an association between the two genes. These findings indicated that the expression level of eps genes is responsible for changes in the yield and monosaccharide composition of exopolysaccharides under environmental stresses.

Effects of annealing temperature on the structure, morphology, and photocatalytic properties of SnO2/rGO nanocomposites.

Water pollution abatement is a problem in today's society that requires urgent attention. Moreover, photocatalysts are an effective method to treat environmental pollution, and SnO2/reduced graphene oxide composite photocatalysts have been extensively studied in recent years. The synthesis parameters for these photocatalysts significantly affect their morphologies, structures, and properties. In this study, we investigated the effects of annealing temperatures on the properties of SnO2/reduced graphene oxide nanocomposites, which were hydrothermally fabricated at 180 °C for 24 h and annealed at 200 °C-800 °C. The structural characteristics of the fabricated nanocomposites were studied via x-ray diffraction, field emission scanning electron microscopy, and Raman scattering analyses. The observed results indicated that increasing the annealing temperature from 200 °C to 800 °C increased the average SnO2 nanoparticle size from 4.60 nm to 9.27 nm; in addition, the Raman scattering peaks of the SnO2 increased, and those of the reduced graphene oxide significantly decreased as the annealing temperature was increased. Furthermore, the specific surface area of the samples decreased due to the increase in calcination temperature. The amount of reduced graphene oxide content in all the samples was measured using thermo-gravimetric analysis. The optical properties of the samples were studied using ltraviolet-visible absorption spectra, and their photocatalytic activity was evaluated by decomposing methylene blue under visible light using the samples as catalysts. In particular, the photocatalytic properties of nanocomposites decreased significantly with increasing annealing temperature. Among the samples, the photocatalytic activity of that annealed at 200 °C is most satisfactory as it has the smallest particle size and the largest specific surface area. The results of our research could facilitate the production of efficient catalysts with suitable properties.

An Advanced Noise Reduction and Edge Enhancement Algorithm.

Complementary metal-oxide-semiconductor (CMOS) image sensors can cause noise in images collected or transmitted in unfavorable environments, especially low-illumination scenarios. Numerous approaches have been developed to solve the problem of image noise removal. However, producing natural and high-quality denoised images remains a crucial challenge. To meet this challenge, we introduce a novel approach for image denoising with the following three main contributions. First, we devise a deep image prior-based module that can produce a noise-reduced image as well as a contrast-enhanced denoised one from a noisy input image. Second, the produced images are passed through a proposed image fusion (IF) module based on Laplacian pyramid decomposition to combine them and prevent noise amplification and color shift. Finally, we introduce a progressive refinement (PR) module, which adopts the summed-area tables to take advantage of spatially correlated information for edge and image quality enhancement. Qualitative and quantitative evaluations demonstrate the efficiency, superiority, and robustness of our proposed method.

Development and Characterization of Novel Conductive Sensing Fibers for In Vivo Nerve Stimulation.

Advancements in electrode technologies to both stimulate and record the central nervous system's electrical activities are enabling significant improvements in both the understanding and treatment of different neurological diseases. However, the current neural recording and stimulating electrodes are metallic, requiring invasive and damaging methods to interface with neural tissue. These electrodes may also degrade, resulting in additional invasive procedures. Furthermore, metal electrodes may cause nerve damage due to their inherent rigidity. This paper demonstrates that novel electrically conductive organic fibers (ECFs) can be used for direct nerve stimulation. The ECFs were prepared using a standard polyester material as the structural base, with a carbon nanotube ink applied to the surface as the electrical conductor. We report on three experiments: the first one to characterize the conductive properties of the ECFs; the second one to investigate the fiber cytotoxic properties in vitro; and the third one to demonstrate the utility of the ECF for direct nerve stimulation in an in vivo rodent model.

Covid-19 pandemic and tail-dependency networks of financial assets.

This study provides evidence on the frequency-based dependency networks of various financial assets in the tails of return distributions given the extreme price movements under the exceptional circumstance of the Covid-19 pandemic, qualified by the IMF as the Great Lockdown. Our results from the quantile cross-spectral analysis and tail-dependency networks show increases in the network density in both lower and upper joint distributions of asset returns. Particularly, we observe an asymmetric impact of the Covid-19 because the left-tail dependencies become stronger and more prevalent than the right-tail dependencies. The cross-asset tail-dependency of equity, currency and commodity also increases considerably, especially in the left-tail, implying a higher degree of tail contagion effects. Meanwhile, Bitcoin and US Treasury bonds are disconnected from both tail-dependency networks, which suggests their safe-haven characteristics.

Single-step RT-qPCR for detection of extracellular vesicle microRNAs in vivo: a time- and cost-effective method.

Emerging evidence suggests that extracellular vesicle (EV)-associated microRNAs (miRNAs) are a potential diagnostic tool for liquid biopsy in various human diseases. However, the experimental procedure for the detection of EV-associated miRNAs (EV-miRNAs) from body fluids is relatively complex and not cost-effective. Due to the limited amount of EVs and EV-RNAs, a column-based RNA purification, which is an expensive approach, is often used to detect EV-miRNAs via reverse transcription-quantitative real-time PCR (RT-qPCR). Here, we developed and validated a simple and cost-effective method (single-step RT-qPCR) in which we directly detect EV-miRNAs without RNA purification from the EVs. We validated this protocol using the EVs isolated from mouse broncho-alveolar lavage fluid (BALF) and serum. The obtained EVs were first lysed in the EV-lysis buffer, followed by RT-qPCR without isolation and purification of RNAs. We successfully detected the designated miRNAs from lysed EVs; 106 to 107 EVs were optimal to detect the EV-miRNAs using the single-step RT-qPCR. In our previously published work, using the conventional RT-qPCR method, we have reported that miR-142 and -223 are dramatically upregulated in both BALF and serum EVs after lung infection. Hence, we reassessed and confirmed the level of EV-miR-142/223 using the newly developed single-step RT-qPCR. Notably, inhibition of RNase activity in the lysed EVs remains crucial for the detection of EV-miRNAs. Moreover, repeated freeze-thaw cycling significantly interferes the EV-miRNA quantification. Collectively, the single-step RT-qPCR for the detection of EV-miRNAs in vivo will potentially provide a fast, accurate, and convenient way to quantify circulating and/or body fluid-derived EV-miRNAs. This method may potentially be applied to the diagnostic blood testing used in the medical centers or research laboratories.

Evaluation of a Liquid Biopsy Protocol using Ultra-Deep Massive Parallel Sequencing for Detecting and Quantifying Circulation Tumor DNA in Colorectal Cancer Patients.

The identification and quantification of actionable mutations are critical for guiding targeted therapy and monitoring drug response in colorectal cancer. Liquid biopsy (LB) based on plasma cell-free DNA analysis has emerged as a noninvasive approach with many clinical advantages over conventional tissue sampling. Here, we developed a LB protocol using ultra-deep massive parallel sequencing and validated its clinical performance for detection and quantification of actionable mutations in three major driver genes (KRAS, NRAS and BRAF). The assay showed a 92% concordance for mutation detection between plasma and paired tissues and great reliability in quantification of variant allele frequency.