The Grafting of Hydroxyaromatic Organics within Layered Perovskites via a Microwave-Assisted Method.

A new series of inorganic-organic hybrid perovskite materials were prepared by microwave-assisted grafting reactions. Simple carboxylic acids, acetic acid, and propionic acid, as well as hydroxyaromatic carboxylic acids, 3,5-dihydroxy benzoic acid (DBA), 5-hydroxyisophthalic acid (HPA), 4-hydroxybenzoic acid (HBA), and 4-hydroxy-4-biphenyl carboxylic acid (HBCA), were reacted with the Dion-Jacobson double-layered perovskite, HLaNb2O7, and its alcoxy derivatives. Grafting was found to not occur with simple carboxylic acids, while those molecules with hydroxyls were all attached to the perovskite interlayers. Reactivity of the hydroxyaromatic carboxylic acids varied with the different layered perovskite hosts where reactions with HLaNb2O7 did not occur, and those with n-propoxy-LaNb2O7 were limited; the greatest extent of reactivity was seen with n-decoxy-LaNb2O7. This is attributed to the larger interlayer spacing available for the insertion of the various hydroxyaromatic carboxylic acid compounds. The loading exhibited by the grafting species was less than that seen with well-known long-chain alkoxy grafting groups. It is expected that the width of the molecules contributes to this where, due to the benzyl groups, the interlayer volume of the grafted moieties occupies a larger horizontal fraction, therefore minimizing the loading to the below half. X-ray powder diffraction and transmission electron microscopy studies found that grafting of the n-decoxy-LaNb2O7 intermediates with the series of hydroxyaromatics resulted in a reduction in crystallinity along with a disruption of the layer structure. Raman data on the series show little variation in local structure except for HBCA, where there appears to be a lengthening of the Nb-O apical linkage and a possible reduction in the distortion of inner-layer NbO6 octahedra. The optical properties of the hydroxyaromatic carboxylic acid grafted perovskites were also investigated using diffuse-reflectance UV-Vis spectroscopy. The band gaps of DBA, HPA, and HBA were found to be similar to the parent (Eg ≈ 3.4 eV), while the HBCA was significantly less by ca. 0.6 eV. This difference is attributed to electron withdrawal from the perovskite block to the HBCA ligand, leading to a lower band gap for the HBCA compound. The methods described herein allow for the formation of a new series of inorganic-organic hybrid materials where the products are of interest as precursors to more complex architectures as well as models for band gap modification of metal oxide photocatalysts.

Correction: Blanco et al. Synthesis and Characterization of [Fe(Htrz)2(trz)](BF4)] Nanocubes. Molecules 2022, 27, 1213.

After publication of the paper [...].

Glucocorticoid receptor-mediated Nr1d1 chromatin circadian misalignment in stress-induced irritable bowel syndrome.

Stress-elevated glucocorticoids cause circadian disturbances and gut-brain axis (GBA) disorders, including irritable bowel syndrome (IBS). We hypothesized that the glucocorticoid receptor (GR/NR3C1) might cause chromatin circadian misalignment in the colon epithelium. We observed significantly decreased core circadian gene Nr1d1 in water avoidance stressed (WAS) BALB/c colon epithelium, like in IBS patients. WAS decreased GR binding at the Nr1d1 promoter E-box (enhancer box), and GR could suppress Nr1d1 via this site. Stress also altered GR binding at the E-box sites along the Ikzf3-Nr1d1 chromatin and remodeled circadian chromatin 3D structures, including Ikzf3-Nr1d1 super-enhancer, Dbp, and Npas2. Intestinal deletion of Nr3c1 specifically abolished these stress-induced transcriptional alternations relevant to IBS phenotypes in BALB/c mice. GR mediated Ikzf3-Nr1d1 chromatin disease related circadian misalignment in stress-induced IBS animal model. This animal model dataset suggests that regulatory SNPs of human IKZF3-NR1D1 transcription through conserved chromatin looping have translational potential based on the GR-mediated circadian-stress crosstalk.

Life history of the endemic Hawaiian hogfish Bodianus albotaeniatus: age, growth and reproduction.

Growth rate, longevity, maturity and spawning seasonality were estimated for the endemic Hawaiian hogfish Bodianus albotaeniatus. The sex-specific von Bertalanffy growth parameters are L∞ = 339 mm fork length (LF ) and K = 0.66 year-1 for females and L∞ = 417 mm LF and K = 0.33 year-1 for males. The maximum age is 22 years. Histological gonad analysis and the absence of small and young males indicate a monandric protogynous hermaphrodite. Size and age at maturity for combined sexes are L50 = 238 mm LF and A50 = 1.6 years.

Rapid Synthesis of Kaolinite Nanoscrolls through Microwave Processing.

Kaolinite nanoscrolls (NScs) are halloysite-like nanotubular structures of great interest due to their ability to superimpose halloysite's properties and applicability. Especially attractive is the ability of these NScs to serve as reaction vessels for the uptake and conversion of different chemical species. The synthesis of kaolinite NScs, however, is demanding due to the various processing steps that lead to extended reaction times. Generally, three intercalation stages are involved in the synthesis, where the second step of methylation dominates others in terms of duration. The present research shows that introducing microwave processing throughout the various steps can simplify the procedure overall and reduce the synthesis period to less than a day (14 h). The kaolinite nanoscrolls were obtained using two final intercalating agents, aminopropyl trimethoxy silane (APTMS) and cetyltrimethylammonium chloride (CTAC). Both produce abundant NScs, as corroborated by microscopy measurements as well as the surface area of the final products; APTMS intercalated NScs were 63.34 m2/g, and CTAC intercalated NScs were 73.14 m2/g. The nanoscrolls averaged about 1 µm in length with outer diameters of APTMS and CTAC intercalated samples of 37.3 ± 8.8 nm and 24.9 ± 6.1 nm, respectively. The availability of methods for the rapid production of kaolinite nanoscrolls will lead to greater utility of these materials in technologically significant applications.

Chronic psychological stress alters gene expression in rat colon epithelial cells promoting chromatin remodeling, barrier dysfunction and inflammation.

Chronic stress is commonly associated with enhanced abdominal pain (visceral hypersensitivity), but the cellular mechanisms underlying how chronic stress induces visceral hypersensitivity are poorly understood. In this study, we examined changes in gene expression in colon epithelial cells from a rat model using RNA-sequencing to examine stress-induced changes to the transcriptome. Following chronic stress, the most significantly up-regulated genes included Atg16l1, Coq10b, Dcaf13, Nat2, Ptbp2, Rras2, Spink4 and down-regulated genes including Abat, Cited2, Cnnm2, Dab2ip, Plekhm1, Scd2, and Tab2. The primary altered biological processes revealed by network enrichment analysis were inflammation/immune response, tissue morphogenesis and development, and nucleosome/chromatin assembly. The most significantly down-regulated process was the digestive system development/function, whereas the most significantly up-regulated processes were inflammatory response, organismal injury, and chromatin remodeling mediated by H3K9 methylation. Furthermore, a subpopulation of stressed rats demonstrated very significantly altered gene expression and transcript isoforms, enriched for the differential expression of genes involved in the inflammatory response, including upregulation of cytokine and chemokine receptor gene expression coupled with downregulation of epithelial adherens and tight junction mRNAs. In summary, these findings support that chronic stress is associated with increased levels of cytokines and chemokines, their downstream signaling pathways coupled to dysregulation of intestinal cell development and function. Epigenetic regulation of chromatin remodeling likely plays a prominent role in this process. Results also suggest that super enhancers play a primary role in chronic stress-associated intestinal barrier dysfunction.

Life history of the humpnose big-eye bream Monotaxis grandoculis.

This study provides estimates of growth rate, longevity, maturity, spawning seasonality and mortality for Hawai'i's only lethrinid, the humpnose big-eye bream (known as Mu in Hawai'i) Monotaxis grandoculis, a commercially and recreationally important species in Hawai'i and throughout the Indo-Pacific. M. grandoculis reaches maturity at 303 mm fork length or 3.6 years of age for both sexes. Males were significantly larger than females for a given age. The von Bertalanffy growth parameters for males and females were L∞  = 506 mm fork length and von Bertalanffy growth coefficient (K) = 0.24 year-1 , and L∞  = 427 mm fork length and K = 0.33 year-1 , respectively. Both males and females reached ages over 20 years old, with a maximum age of 23 years. M. grandoculis had a distinct spawning season from May through August with corresponding elevated female gonadosomatic index. An age-based multinomial catch curve indicated that the commercial exploitation rate (natural mortality/fishing mortality) was 0.48 year-1 , which is considered below the overfishing limit.

Synthesis and Characterization of [Fe(Htrz)2(trz)](BF4)] Nanocubes.

Compounds that exhibit spin-crossover (SCO) type behavior have been extensively investigated due to their ability to act as molecular switches. Depending on the coordinating ligand, in this case 1H-1,2,4-triazole, and the crystallite size of the SCO compound produced, the energy requirement for the spin state transition can vary. Here, SCO [Fe(Htrz)2(trz)](BF4)] nanoparticles were synthesized using modified reverse micelle methods. Reaction conditions and reagent ratios are strictly controlled to produce nanocubes of 40-50 nm in size. Decreases in energy requirements are seen in both thermal and magnetic transitions for the smaller sized crystallites, where, compared to bulk materials, a decrease of as much as 20 °C can be seen in low to high spin state transitions.

Platinum@Hexaniobate Nanopeapods: A Directed Photocatalytic Architecture for Dye-Sensitized Semiconductor H2 Production under Visible Light Irradiation.

Platinum@hexaniobate nanopeapods (Pt@HNB NPPs) are a nanocomposite photocatalyst that was selectively engineered to increase the efficiency of hydrogen production from visible light photolysis. Pt@HNB NPPs consist of linear arrays of high surface area Pt nanocubes encapsulated within scrolled sheets of the semiconductor H x K4-x Nb6O17 and were synthesized in high yield via a facile one-pot microwave heating method that is fast, reproducible, and more easily scalable than multi-step approaches required by many other state-of-the-art catalysts. The Pt@HNB NPPs' unique 3D architecture enables physical separation of the Pt catalysts from competing surface reactions, promoting electron efficient delivery to the isolated reduction environment along directed charge transport pathways that kinetically prohibit recombination reactions. Pt@HNB NPPs' catalytic activity was assessed in direct comparison to representative state-of-the-art Pt/semiconductor nanocomposites (extPt-HNB NScs) and unsupported Pt nanocubes. Photolysis under similar conditions exhibited superior H2 production by the Pt@HNB NPPs, which exceeded other catalyst H2 yields (µmol) by a factor of 10. Turnover number and apparent quantum yield values showed similar dramatic increases over the other catalysts. Overall, the results clearly demonstrate that Pt@HNB NPPs represent a unique, intricate nanoarchitecture among state-of-the-art heterogeneous catalysts, offering obvious benefits as a new architectural pathway toward efficient, versatile, and scalable hydrogen energy production. Potential factors behind the Pt@HNB NPPs' superior performance are discussed below, as are the impacts of systematic variation of photolysis parameters and the use of a non-aqueous reductive quenching photosystem.

The Role of Epigenomic Regulatory Pathways in the Gut-Brain Axis and Visceral Hyperalgesia.

The gut-brain axis (GBA) is broadly accepted to describe the bidirectional circuit that links the gastrointestinal tract with the central nervous system (CNS). Interest in the GBA has grown dramatically over past two decades along with advances in our understanding of the importance of the axis in the pathophysiology of numerous common clinical disorders including mood disorders, neurodegenerative disease, diabetes mellitus, non-alcohol fatty liver disease (NAFLD) and enhanced abdominal pain (visceral hyperalgesia). Paralleling the growing interest in the GBA, there have been seminal developments in our understanding of how environmental factors such as psychological stress and other extrinsic factors alter gene expression, primarily via epigenomic regulatory mechanisms. This process has been driven by advances in next-generation multi-omics methods and bioinformatics. Recent reviews address various components of GBA, but the role of epigenomic regulatory pathways in chronic stress-associated visceral hyperalgesia in relevant regions of the GBA including the amygdala, spinal cord, primary afferent (nociceptive) neurons, and the intestinal barrier has not been addressed. Rapidly developing evidence suggests that intestinal epithelial barrier dysfunction and microbial dysbiosis play a potentially significant role in chronic stress-associated visceral hyperalgesia in nociceptive neurons innervating the lower intestine via downregulation in intestinal epithelial cell tight junction protein expression and increase in paracellular permeability. These observations support an important role for the regulatory epigenome in the development of future diagnostics and therapeutic interventions in clinical disorders affecting the GBA.

Microwave Synthetic Routes for Shape-Controlled Catalyst Nanoparticles and Nanocomposites.

The use of microwave irradiation for the synthesis of inorganic nanomaterials has recently become a widespread area of research that continues to expand in scope and specialization. The growing demand for nanoscale materials with composition and morphology tailored to specific applications requires the development of facile, repeatable, and scalable synthetic routes that offer a high degree of control over the reaction environment. Microwave irradiation provides unique advantages for developing such routes through its direct interaction with active reaction species, which promotes homogeneous heat distribution, increased reaction rates, greater product quality and yield, and use of mild reaction conditions. Many catalytic nanomaterials such as noble metal nanoparticles and intricate nanocomposites have very limited synthetic routes due to their extreme temperature sensitivity and difficulty achieving homogeneous growth. This work presents recent advances in the use of MW irradiation methods to produce high-quality nanoscale composites with controlled size, morphology, and architecture.

Age, growth and maturity for two highly targeted jack species: Caranx ignobilis and Caranx melampygus.

This study provides growth rate, longevity and maturity estimates for the two important species of jack in Hawai'i: ulua aukea/giant trevally Caranx ignobilis and omilu/bluefin trevally Caranx melampygus. Maximum observed ages for C. ignobilis and C. melampygus were 31 years and 24 years, respectively. Combined sex von Bertalanffy growth parameter values for C. ignobilis and C. melampygus were as follows: L∞  = 1064 mm and K = 0.18 year-1 ; and L∞  = 718 mm and K = 0.20 year-1 , respectively. Female size at maturity was significantly greater than males for both C. ignobilis and C. melampygus. Size and age at maturity for C. ignobilis was 594 mm and 4.4 years for females and 465 mm and 2.8 years for males. Size and age at maturity for C. melampygus was 372 mm and 4.1 years for females and 329 mm and 2.9 years for males. This study provides the first robust demographic data for both of these highly prized and ecologically important predatory species in Hawai'i, which can be used for future assessments or management.

Histone H3K9 methylation regulates chronic stress and IL-6-induced colon epithelial permeability and visceral pain.

BACKGROUND: Chronic stress is associated with activation of the HPA axis, elevation in pro-inflammatory cytokines, decrease in intestinal epithelial cell tight junction (TJ) proteins, and enhanced visceral pain. It is unknown whether epigenetic regulatory pathways play a role in chronic stress-induced intestinal barrier dysfunction and visceral hyperalgesia. METHODS: Young adult male rats were subjected to water avoidance stress ± H3K9 methylation inhibitors or siRNAs. Visceral pain response was assessed. Differentiated Caco-2/BBE cells and human colonoids were treated with cortisol or IL-6 ± antagonists. Expression of TJ, IL-6, and H3K9 methylation status at gene promoters was measured. Transepithelial electrical resistance and FITC-dextran permeability were evaluated. KEY RESULTS: Chronic stress induced IL-6 up-regulation prior to a decrease in TJ proteins in the rat colon. The IL-6 level inversely correlated with occludin expression. Treatment with IL-6 decreased occludin and induced visceral hyperalgesia. Chronic stress and IL-6 increased H3K9 methylation and decreased transcriptional GR binding to the occludin gene promoter, leading to down-regulation of protein expression and increase in paracellular permeability. Intrarectal administration of a H3K9 methylation antagonist prevented chronic stress-induced visceral hyperalgesia in the rat. In a human colonoid model, cortisol decreased occludin expression, which was prevented by the GR antagonist RU486, and IL-6 increased H3K9 methylation and decreased TJ protein levels, which were prevented by inhibitors of H3K9 methylation. CONCLUSIONS & INFERENCES: Our findings support a novel role for methylation of the repressive histone H3K9 to regulate chronic stress, pro-inflammatory cytokine-mediated reduction in colon TJ protein levels, and increase in paracellular permeability and visceral hyperalgesia.

Chromosome evolution in Lophyohylini (Amphibia, Anura, Hylinae).

The hyline tribe Lophyohylini includes 87 species of treefrogs, of which cytogenetics aspects have been studied in less than 20% of them. In order to evaluate the evolution of some of its chromosome characters (NOR position, C-bands, and DAPI/CMA3 bands), we studied the karyotypes of 21 lophyohylines, 16 of them for the first time, and analyzed them in a phylogenetic context. Most species showed similar karyotypes regarding chromosome number (2n = 24) and morphology (FN = 48), excepting Phyllodytes edelmoi and Osteocephalus buckleyi with 2n = 22 (FN = 44) and 2n = 28 (FN = 50), respectively. The NOR location was variable among species and provided valuable phylogenetic information. This marker was located in pair 11 in all species of Trachycephalus, Itapotihyla langsdorffii, and Nyctimantis arapapa, representing the plesiomorphic condition of Lophyohylini. Besides, other apomorphic states were recovered for the clades comprising N. rugiceps and N. siemersi (NOR in pair 5), and Dryaderces pearsoni, Osteocephalus, and Osteopilus (NOR in pair 9). Phyllodytes presented variation for NORs position; they were in pair 2 in P. edelmoi, pair 7 in P. melanomystax, and pair 8 in P. gyrinaethes and P. praeceptor. Polymorphisms in size, number, and activity of this marker were observed for N. siemersi, Osteocephalus fuscifacies, and some species of Trachycephalus. Remarkably, in N. siemersi NORs were detected on a single chromosome in the two specimens studied by this technique, raising the question of how this complex polymorphism is maintained. Interstitial telomeric sequences were found in P. edelmoi, P. melanomystax, and Osteocephalus buckleyi, and their presence seems to be not related to the chromosome reorganization events. Finally, some species showed spontaneous rearrangements, possibly as a consequence of an uncommon phenomenon in anuran cytogenetics: the presence of fragile sites or secondary constrictions not associated with NORs. We propose that this rare feature would have played an important role in the evolution of this group of frogs. From the evidence obtained in this and previous studies, we conclude that Lophyohylini presents a complex chromosome evolution.

Mitsui-7, heat-treated, and nitrogen-doped multi-walled carbon nanotubes elicit genotoxicity in human lung epithelial cells.

BACKGROUND: The unique physicochemical properties of multi-walled carbon nanotubes (MWCNT) have led to many industrial applications. Due to their low density and small size, MWCNT are easily aerosolized in the workplace making respiratory exposures likely in workers. The International Agency for Research on Cancer designated the pristine Mitsui-7 MWCNT (MWCNT-7) as a Group 2B carcinogen, but there was insufficient data to classify all other MWCNT. Previously, MWCNT exposed to high temperature (MWCNT-HT) or synthesized with nitrogen (MWCNT-ND) have been found to elicit attenuated toxicity; however, their genotoxic and carcinogenic potential are not known. Our aim was to measure the genotoxicity of MWCNT-7 compared to these two physicochemically-altered MWCNTs in human lung epithelial cells (BEAS-2B & SAEC). RESULTS: Dose-dependent partitioning of individual nanotubes in the cell nuclei was observed for each MWCNT material and was greatest for MWCNT-7. Exposure to each MWCNT led to significantly increased mitotic aberrations with multi- and monopolar spindle morphologies and fragmented centrosomes. Quantitative analysis of the spindle pole demonstrated significantly increased centrosome fragmentation from 0.024-2.4 µg/mL of each MWCNT. Significant aneuploidy was measured in a dose-response from each MWCNT-7, HT, and ND; the highest dose of 24 µg/mL produced 67, 61, and 55%, respectively. Chromosome analysis demonstrated significantly increased centromere fragmentation and translocations from each MWCNT at each dose. Following 24 h of exposure to MWCNT-7, ND and/or HT in BEAS-2B a significant arrest in the G1/S phase in the cell cycle occurred, whereas the MWCNT-ND also induced a G2 arrest. Primary SAEC exposed for 24 h to each MWCNT elicited a significantly greater arrest in the G1 and G2 phases. However, SAEC arrested in the G1/S phase after 72 h of exposure. Lastly, a significant increase in clonal growth was observed one month after exposure to 0.024 µg/mL MWCNT-HT & ND. CONCLUSIONS: Although MWCNT-HT & ND cause a lower incidence of genotoxicity, all three MWCNTs cause the same type of mitotic and chromosomal disruptions. Chromosomal fragmentation and translocations have not been observed with other nanomaterials. Because in vitro genotoxicity is correlated with in vivo genotoxic response, these studies in primary human lung cells may predict the genotoxic potency in exposed human populations.

Room-Temperature Aqueous Suzuki-Miyaura Cross-Coupling Reactions Catalyzed via a Recyclable Palladium@Halloysite Nanocomposite.

A reliable method for encapsulation of palladium nanoparticles (6-8 nm particles) in halloysite (Pd@Hal) has been developed. The Pd@Hal was found to be a highly efficient room-temperature catalyst for Suzuki-Miyaura cross-coupling reactions that gave high yields of a diverse array of coupling products in 5:2 n-PrOH/H2O within 1 h. The catalytic system was remarkably effective with a broad substrate scope. In addition, the catalyst was easily recovered and recycled without a significant loss of catalytic activity.

Chronic stress and intestinal permeability: Lubiprostone regulates glucocorticoid receptor-mediated changes in colon epithelial tight junction proteins, barrier function, and visceral pain in the rodent and human.

BACKGROUND: Chronic psychological stress is associated with increased intestinal epithelial permeability and visceral hyperalgesia. Lubiprostone, an agonist for chloride channel-2, promotes secretion and accelerates restoration of injury-induced epithelial barrier dysfunction. The mechanisms underlying how lubiprostone regulates colon epithelial barrier function and visceral hyperalgesia in chronic stress remain unknown. METHODS: Male rats were subjected to water avoidance stress for 10 consecutive days. Lubiprostone was administered daily during the stress phase. Visceromotor response to colorectal distension was measured. Human colon crypts and cell lines were treated with cortisol and lubiprostone. The transepithelial electrical resistance and FITC-dextran permeability were assayed. Chromatin immunoprecipitation was conducted to assess glucocorticoid receptor binding at tight junction gene promoters. KEY RESULTS: Lubiprostone significantly decreased chronic stress-induced visceral hyperalgesia in the rat (P < 0.05; n = 6). WA stress decreased occludin and claudin-1 and increased claudin-2 in rat colon crypts, which was prevented by lubiprostone. Cortisol treatment induced similar alterations of tight junction protein expression in Caco-2/BBE cells (P < 0.05) and significantly changed paracellular permeability in monolayers (P < 0.01). These changes were blocked by lubiprostone. Glucocorticoid receptor and its binding at occludin promoter region were decreased in cortisol-treated cells and human colon crypts, which was largely reversed by lubiprostone. In rat colonic cells, glucocorticoid receptor and its co-chaperone proteins were down-regulated after corticosterone treatment and lubiprostone reversed these changes. CONCLUSIONS & INFERENCES: Lubiprostone preferentially prevents chronic stress-induced alterations of intestinal epithelial tight junctions, barrier function, and visceral hyperalgesia that was associated with modulation of glucocorticoid receptor expression and function.

Publisher Correction: 3D Shape Modeling for Cell Nuclear Morphological Analysis and Classification.

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3D Shape Modeling for Cell Nuclear Morphological Analysis and Classification.

Quantitative analysis of morphological changes in a cell nucleus is important for the understanding of nuclear architecture and its relationship with pathological conditions such as cancer. However, dimensionality of imaging data, together with a great variability of nuclear shapes, presents challenges for 3D morphological analysis. Thus, there is a compelling need for robust 3D nuclear morphometric techniques to carry out population-wide analysis. We propose a new approach that combines modeling, analysis, and interpretation of morphometric characteristics of cell nuclei and nucleoli in 3D. We used robust surface reconstruction that allows accurate approximation of 3D object boundary. Then, we computed geometric morphological measures characterizing the form of cell nuclei and nucleoli. Using these features, we compared over 450 nuclei with about 1,000 nucleoli of epithelial and mesenchymal prostate cancer cells, as well as 1,000 nuclei with over 2,000 nucleoli from serum-starved and proliferating fibroblast cells. Classification of sets of 9 and 15 cells achieved accuracy of 95.4% and 98%, respectively, for prostate cancer cells, and 95% and 98% for fibroblast cells. To our knowledge, this is the first attempt to combine these methods for 3D nuclear shape modeling and morphometry into a highly parallel pipeline workflow for morphometric analysis of thousands of nuclei and nucleoli in 3D.