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Decreases in cell division at the stationary phase in bacterial cultures are often due to the depletion of nutrients and/or accumulation of toxic waste products. Yet, during the stationary phase, the highly radiation-resistant bacteriumDeinococcus radioduransundergoes new rounds of cell division when Mn(II) is added to the medium in a phenomenon known as manganese-induced cell division (MnCD). When cells were cultured in medium without Mn(II)-enrichment, a heat-resistant, proteinase K-resistant factor (or factors) with a molecular mass less than 10 kD accumulated in the spent medium. Inclusion of the concentrated spent medium in fresh medium could inhibit the growth ofD. radioduranssignificantly, and the degree of inhibition was dose dependent. However, the relative stimulatory effect of MnCD was also dose dependent—the higher the inhibition, the stronger was the MnCD response. Previous studies have shown that nutrients were not limiting and deinococcal cells would continue metabolizing its nutrients at stationary phase. Cells became more sensitive to radiation when nutrients in the medium eventually became depleted. We speculated thatD. radioduransmight produce this factor in the medium to control its population density. The reduction in cell population would conserve the nutrients that in turn might enhance the survival of the species. [ABSTRACT FROM AUTHOR]

Picoplankton (cells with a diameter of 0.2–3.0 μm) is the dominant contributor to both primary production and biomass in the ocean. Most of the previous studies on picoplankton have been conducted in the oligotrophic open sea with few in the eutrophic area. In this study, we investigated the dynamics of different groups of picoplankton and the diversity of picoeukaryote (based on 18S rDNA) in a hyper-eutrophic marine coastal lagoon. The results indicated that temperature and phosphate concentration were most responsible for the dynamics of different picoplankton groups. Examination of 135 clones revealed 27 different Denaturing Gradient Gel Electrophoresis (DGGE) patterns. At least 7 high-level taxonomic groups of picoeukaryote were recorded. The picoeukaryotic diversities included Alveolates, Stramenopiles, Haptophyceae, and Viridiplantae, with Stramenopiles being the most diverse group. Overall the results of this study indicated that picoplankton diversity was low relative to studies conducted in more oligotrophic waters. [ABSTRACT FROM AUTHOR]

The aim of this study was to report the successful results on voluntary spawning of Plectorhinchus vittatus, a description of larval and juvenile development stages, and appropriate first-feed items for pilot-scale larviculture systems. Spontaneous spawning of P. vittatus in captivity from 11 April to 22 June, 2009, was described for the first time. Over a 73-d period, the female produced 49 spawns, 75.1% of which resulted in fertile eggs. The average fecundity per spawn was 4170 eggs (range 2090-7080 eggs). Fertilized eggs were spherical, buoyant, and had a diameter of 0.80 ± 0.02 mm (mean ± SD). Newly hatched larvae were 1.90 ± 0.06 mm in total length (TL) with 28 myomeres. Transformation of larvae to the juvenile stage was completed at 9.58 ± 0.69 mm TL. A statistical model: Y = ( X× 0.5034) − ( X2× 0.0004) − 0.5883, where Y is mean TL (mm) and X represents days post hatch, explained 99.57% of variation in growth ( P < 0.001, R2 = 0.9957). The effects of live feed on survival was significantly ( P < 0.05) higher in larvae fed a combination of diet (rotifers, copepods, and Artemia) than the others. These results indicate that P. vittatus is a potential species for captive breeding programs and the use of a combination of diet may be a suitable first food for the larviculture. [ABSTRACT FROM AUTHOR]

Background: The efficiencies of the stop codons TAA, TAG, and TGA in protein synthesis termination are not the same. These variations could allow many genes to be regulated. There are many similar nucleotide trimers found on the second and third reading-frames of a gene. They are called premature stop codons (PSC). Like stop codons, the PSC in bacterial genomes are also highly bias in terms of their quantities and qualities on the genes. Phylogenetically related species often share a similar PSC profile. We want to know whether the selective forces that influence the stop codons and the PSC usage biases in a genome are related. We also wish to know how strong these trimers in a genome are related to the natural history of the bacterium. Knowing these relations may provide better knowledge in the phylogeny of bacteria Results: A 16SrRNA-alignment tree of 19 well-studied α-, β- and γ-Proteobacteria Type species is used as standard reference for bacterial phylogeny. The genomes of sixty-one bacteria, belonging to the α-, β- and γ-Proteobacteria subphyla, are used for this study. The stop codons and PSC are collectively termed “Translation Stop Signals” (TSS). A gene is represented by nine scalars corresponding to the numbers of counts of TAA, TAG, and TGA on each of the three reading-frames of that gene. “Translation Stop Signals Ratio” (TSSR) is the ratio between the TSS counts. Four types of TSSR are investigated. The TSSR-1, TSSR-2 and TSSR-3 are each a 3-scalar series corresponding respectively to the average ratio of TAA: TAG: TGA on the first, second, and third reading-frames of all genes in a genome. The Genomic-TSSR is a 9-scalar series representing the ratio of distribution of all TSS on the three reading-frames of all genes in a genome. Results show that bacteria grouped by their similarities based on TSSR-1, TSSR-2, or TSSR-3 values could only partially resolve the phylogeny of the species. However, grouping bacteria based on thier Genomic-TSSR values resulted in clusters of bacteria identical to those bacterial clusters of the reference tree. Unlike the 16SrRNA method, the Genomic-TSSR tree is also able to separate closely related species/strains at high resolution. Species and strains separated by the Genomic-TSSR grouping method are often in good agreement with those classified by other taxonomic methods. Correspondence analysis of individual genes shows that most genes in a bacterial genome share a similar TSSR value. However, within a chromosome, the Genic-TSSR values of genes near the replication origin region (Ori) are more similar to each other than those genes near the terminus region (Ter). Conclusion: The translation stop signals on the three reading-frames of the genes on a bacterial genome are interrelated, possibly due to frequent off-frame recombination facilitated by translational-associated recombination (TSR). However, TSR may not occur randomly in a bacterial chromosome. Genes near the Ori region are often highly expressed and a bacterium always maintains multiple copies of Ori. Frequent collisions between DNA- polymerase and RNA-polymerase would create many DNA strand-breaks on the genes; whereas DNA strand-break induced homologues-recombination is more likely to take place between genes with similar sequence. Thus, localized recombination could explain why the TSSR of genes near the Ori region are more similar to each other. The quantity and quality of these TSS in a genome strongly reflect the natural history of a bacterium. We propose that the Genomic- TSSR can be used as a subjective biomarker to represent the phyletic status of a bacterium. [ABSTRACT FROM AUTHOR]

We have analyzed synonymous codon usage in the genome of A. tamarense CCMP 1598 for protein-coding sequences from 10865 expressed sequence tags (ESTs). We reconstructed a total of 4284 unigenes, including 74 ribosomal protein and 40 plastid-related genes, from ESTs using FrameDP, an open reading frame (ORF) prediction program. Correspondence analysis of A. tamarense genes based on codon usage showed that the GC content at the third base of synonymous codons (GC3s) was strongly correlated with the first axis (r = 0.93 with P<.001). On the other hand, the second axis discriminated between presumed highly and low expressed genes, with expression levels being confirmed by the analysis of EST frequencies (r =-0.89 with P<.001). Our results suggest that mutational bias is the major factor in shaping codon usage in A. tamarense genome, but other factors, namely, translational selection, hydropathy, and aromaticity, also appear to influence the selection of codon usage in this species. [ABSTRACT FROM AUTHOR]

CpG oligodeoxynucleotides (CpG ODNs), the artificial versions of unmethylated CpG motifs that were originally discovered in bacterial DNA, are demonstrated not only as potent immunoadjuvants but also as anticancer agents by triggering toll-like receptor 9 (TLR9) activation in immune cells. TLR9 activation triggered by CpG ODN has been shown to activate plasmacytoid dendritic cells (pDCs) and cytotoxic T lymphocytes (CTLs), enhancing T cell-mediated antitumor immunity. However, the extent of antitumor immunity carried by TLR agonists has not been optimized individually or in combinations with cancer vaccines, resulting in a decreased preference for TLR agonists as adjuvants in clinical trials. Although various combination therapies involving CpG ODNs have been applied in clinical trials, none of the CpG ODN-based drugs have been approved by the FDA, owing to the short half-life of CpG ODNs in serum that leads to low activation of natural killer cells (NK cells) and CTLs, along with increases of pro-inflammatory cytokine productions. This review summarized the current innovation on CpG ODNs that are under clinical investigation and explored the future direction for CpG ODN-based nanomedicine as an anticancer monotherapy. [ABSTRACT FROM AUTHOR]

A novel, cellulolytic, bacterial thermophilic strain, T4, was isolated from sugar refinery wastewater in southern Taiwan. This isolate, a Gram-negative, motile, aerobically growing sporulating rod, can secrete thermostable endocellulase (endo-1,4-ß-D-glucanase, EC 3.2.1.4) and hydrolyze carboxymethylcellulose (CMC), phosphoric acid-swollen cellulose, Avicel, filter paper, and salicin. When strain T4 was grown in CMC medium, the cellulolytic enzyme activity in culture supernatants was stable up to 70°C. More than 10% of the original activity was still detectable after heating to 100°C with a pH 7.0 for 1 h. Based on 16S rDNA sequence analysis, DNA base composition, phenotypic and physiological characteristics, as well as DNA-DNA hybridization, strain T4 was classified asGeobacillus thermoleovoransT4 (DSM 14791 = CCRC 17200). We also demonstrated that the type speciesG. stearothermophilus(DSM 22 = ATCC 12980) could hydrolyze amorphous and crystalline (filter paper) celluloses at a rate of 13 and 14%, respectively, in comparison with strain T4. [ABSTRACT FROM AUTHOR]

PbSe is an attractive thermoelectric material due to its favorable electronic structure, high melting point, and lower cost compared to PbTe. Herein, the hitherto unexplored alloys of PbSe with NaSbSe2 (NaPbmSbSem+2) are described and the most promising p‐type PbSe‐based thermoelectrics are found among them. Surprisingly, it is observed that below 500 K, NaPbmSbSem+2 exhibits unorthodox semiconducting‐like electrical conductivity, despite possessing degenerate carrier densities of ≈1020 cm−3. It is shown that the peculiar behavior derives from carrier scattering by the grain boundaries. It is further demonstrated that the high solubility of NaSbSe2 in PbSe augments both the thermoelectric properties while maintaining a rock salt structure. Namely, density functional theory calculations and photoemission spectroscopy demonstrate that introduction of NaSbSe2 lowers the energy separation between the L‐ and Σ‐valence bands and enhances the power factors under 700 K. The crystallographic disorder of Na+, Pb2+, and Sb3+ moreover provides exceptionally strong point defect phonon scattering yielding low lattice thermal conductivities of 1–0.55 W m‐1 K‐1 between 400 and 873 K without nanostructures. As a consequence, NaPb10SbSe12 achieves maximum ZT ≈1.4 near 900 K when optimally doped. More importantly, NaPb10SbSe12 maintains high ZT across a broad temperature range, giving an estimated record ZTavg of ≈0.64 between 400 and 873 K, a significant improvement over existing p‐type PbSe thermoelectrics. [ABSTRACT FROM AUTHOR]

Nanostructuring to reduce thermal conductivity is among the most promising strategies for designing next‐generation, high‐performance thermoelectric materials. In practice, electrical grain boundary resistance can overwhelm the thermal conductivity reduction induced by nanostructuring, which results in worse overall performance. Since a large body of work has characterized the transport of both polycrystalline ceramics and single crystals of SrTiO3, it is an ideal material system for conducting a case study of electrical grain boundary resistance. An effective mass model is used to characterize the transport signatures of electrical grain boundary resistance and evaluate thermodynamic design principles for controlling that resistance. Treating the grain boundary as a secondary phase to the bulk crystallites explains the transport phenomena. Considering that the interface can be engineered by controlling oxygen partial pressure, temperature, and the addition of extrinsic elements into the grain boundary phase, the outlook for SrTiO3 as a nanostructured thermoelectric is promising, and the zT could be greater than 0.5 at room temperature. [ABSTRACT FROM AUTHOR]

Highly resistive grain boundaries significantly reduce the electrical conductivity that compromises the thermoelectric figure‐of‐merit zT in n‐type polycrystalline Mg3Sb2. In this work, discovered is a Mg deficiency near grain boundaries using atom‐probe tomography. Approximately 5 at% of Mg deficiency is observed uniformly in a 10 nm region along the grain boundary without any evidence of a stable secondary or impurity phase. The off‐stoichiometry can prevent n‐type dopants from providing electrons, lowering the local carrier concentration near the grain boundary and thus the local conductivity. This observation explains how nanometer scale compositional variations can dramatically determine thermoelectric zT, and provides concrete strategies to reduce grain‐boundary resistance and increase zT in Mg3Sb2‐based materials. [ABSTRACT FROM AUTHOR]

A new caryophyllane-type tetrahydropyran norsesquiterpenoid, rumphellolide G (1), has been isolated from the gorgonian coral Rumphella antipathies, collected off southern Taiwan coast. The structure of caryophyllane 1 was elucidated by the interpretation of spectral data. [ABSTRACT FROM AUTHOR]

Lipid-based nanoparticles (LBNPs) are biocompatible and biodegradable vesicles that are considered to be one of the most efficient drug delivery platforms. Due to the prominent advantages, such as long circulation time, slow drug release, reduced toxicity, high transfection efficiency, and endosomal escape capacity, such synthetic nanoparticles have been widely used for carrying genetic therapeutics, particularly nucleic acids that can be applied in the treatment for various diseases, including congenital diseases, cancers, virus infections, and chronic inflammations. Despite great merits and multiple successful applications, many extracellular and intracellular barriers remain and greatly impair delivery efficacy and therapeutic outcomes. As such, the current state of knowledge and pitfalls regarding the gene delivery and construction of LBNPs will be initially summarized. In order to develop a new generation of LBNPs for improved delivery profiles and therapeutic effects, the modification strategies of LBNPs will be reviewed. On the basis of these developed modifications, the performance of LBNPs as therapeutic nanoplatforms have been greatly improved and extensively applied in immunotherapies, including infectious diseases and cancers. However, the therapeutic applications of LBNPs systems are still limited due to the undesirable endosomal escape, potential aggregation, and the inefficient encapsulation of therapeutics. Herein, we will review and discuss recent advances and remaining challenges in the development of LBNPs for nucleic acid-based immunotherapy. [ABSTRACT FROM AUTHOR]

Abstract: A novel chloride-containing 14C norsesquiterpenoid, rumphellatin A (1), was isolated from the Formosan gorgonian coral Rumphella antipathies. The structure of metabolite 1 was determined on the basis of spectral data analysis and the configuration of 1 was further supported by molecular mechanics calculations. Rumphellatin A (1) showed activity against Gram-negative bacteria. [Copyright &y& Elsevier]

Zintl compound n-type Mg3(Sb,Bi)2 was recently found to exhibit excellent thermoelectric figure of merit zT (~1.5 at around 700 K). To improve the thermoelectric performance in the whole temperature range of operation from room temperature to 720 K, we investigated how the grain size of sintered samples influences electronic and thermal transport. By increasing the average grain size from 1.0 µm to 7.8 µm, the Hall mobility below 500 K was significantly improved, possibly due to suppression of grain boundary scattering. We also confirmed that the thermal conductivity did not change by increasing the grain size. Consequently, the sample with larger grains exhibited enhanced average zT. The calculated efficiency of thermoelectric power generation reaches 14.5% (ΔT = 420 K), which is quite high for a polycrystalline pristine material. [ABSTRACT FROM AUTHOR]

Two novel 16-membered tetraene marcolides, bafilomycins N ( 1 ) and O ( 2 ), along with two known analogues, JBIR-100 ( 3 ) and bafilomycin K ( 4 ) were produced from isolate GIC10-1, a Streptomyces sp. strain that was originally cloned from bacterial communities associated with marine sponge Theonella sp. The structures of new bafilomycins 1 and 2 were established by using spectroscopic methods and comparing the spectroscopic data with those of known related metabolites. Compounds 1 and 2 were proven to be the first 14-methylbafilomycins to be isolated. Cytotoxicity of these compounds toward various cancer cell lines also is described. [ABSTRACT FROM AUTHOR]

Two pennate diatoms, Amphora coffeaeformis and Nitzschia ovalis, were used to evaluate potential responses to the future CO and temperature increases with respect to cell-specific growth rate, elemental composition, size, population growth rate, and carrying capacity. Diatoms were subjected to four different treatments over a 2 week period (approximately 4 generations): a control (28°C and present-day CO, ~400 ppm), high CO (28°C with high CO, ~750 ppm), high temperature (31°C and present-day CO, ~400 ppm), and greenhouse-effect treatment (31°C with high CO, ~750 ppm). The results indicated that both the cell-specific growth rates and the carrying capacity of A. coffeaeformis decreased at the higher temperature treatment, whereas N. ovalis did not differ among all treatments. No significant difference was found in either species' elemental cell composition, but higher C:N and C:P ratios were observed for A. coffeaeformis and N. ovalis, respectively, in high CO and greenhouse-effect treatments. Smaller cell sizes were observed for both species under the greenhouse-effect treatment, a phenomenon that could alter benthic food webs in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] A novel cembranoid, (1 R ,7 R ,8 R ,11 R ,12 R)-7,8:11,12-bisepoxycembrene A (1), was isolated from an octocoral Sinularia sp. The structure of 1 was elucidated using spectroscopic methods, and its absolute configuration was confirmed by a single-crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Neuroinflammation and accumulation of Amyloid Beta (Aβ) accompanied by deterioration of special memory are hallmarks of Alzheimer's disease (AD). Effective preventative and treatment options for AD are still needed. Microglia in AD brains are characterized by elevated levels of microRNA-17 (miR-17), which is accompanied by defective autophagy, Aβ accumulation, and increased inflammatory cytokine production. However, the effect of targeting miR-17 on AD pathology and memory loss is not clear. To specifically inhibit miR-17 in microglia, we generated mannose-coated lipid nanoparticles (MLNPs) enclosing miR-17 antagomir (Anti-17 MLNPs), which are targeted to mannose receptors readily expressed on microglia. We used a 5XFAD mouse model (AD) that recapitulates many AD-related phenotypes observed in humans. Our results show that Anti-17 MLNPs, delivered to 5XFAD mice by intra-cisterna magna injection, specifically deliver Anti-17 to microglia. Anti-17 MLNPs downregulated miR-17 expression in microglia but not in neurons, astrocytes, and oligodendrocytes. Anti-17 MLNPs attenuated inflammation, improved autophagy, and reduced Aβ burdens in the brains. Additionally, Anti-17 MLNPs reduced the deterioration in spatial memory and decreased anxiety-like behavior in 5XFAD mice. Therefore, targeting miR-17 using MLNPs is a viable strategy to prevent several AD pathologies. This selective targeting strategy delivers specific agents to microglia without the adverse off-target effects on other cell types. Additionally, this approach can be used to deliver other molecules to microglia and other immune cells in other organs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Organic agriculture is a farming method that provides healthy food and is friendly to the environment, and it is developing rapidly worldwide. This study compared microbial communities in organic farming (Or) paddy fields to those in nonorganic farming (Nr) paddy fields based on 16S rDNA sequencing and analysis. The predominant microorganisms in both soils were Proteobacteria, Chloroflexi, Acidobacteria, Actinobacteria, and Nitrospirota. The alpha diversity of the paddy soil microbial communities was not different between the nonorganic and organic farming systems. The beta diversity of nonmetric multidimensional scaling (NMDS) revealed that the two groups were significantly separated. Distance-based redundancy analysis (db-RDA) suggested that soil pH and electrical conductivity (EC) had a positive relationship with the microbes in organic paddy soils. There were 23 amplicon sequence variants (ASVs) that showed differential abundance. Among them, g&#95;B1-7BS (Proteobacteria), s&#95;Sulfuricaulis limicola (Proteobacteria), g&#95;GAL15 (p&#95;GAL15), c&#95;Thermodesulfovibrionia (Nitrospirota), two of f&#95;Anaerolineaceae (Chloroflexi), and two of g&#95;S085 (Chloroflexi) showed that they were more abundant in organic soils, whereas g&#95;11-24 (Acidobacteriota), g&#95;&#95;Subgroup&#95;7 (Acidobacteriota), and g&#95;Bacillus (Firmicutes) showed differential abundance in nonorganic paddy soils. Functional prediction of microbial communities in paddy soils showed that functions related to carbohydrate metabolism could be the major metabolic activities. Our work indicates that organic farming differs from nonorganic farming in terms of microbial composition in paddy soils and provides specific microbes that might be helpful for understanding soil fertility., (© 2023. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)

Human serum albumin (HSA) improves the pharmacokinetic profile of drugs attached to it, making it an attractive carrier with proven clinical success. In our previous studies, we have shown that Caveolin-1 (Cav-1) and caveolae-mediated endocytosis play important roles in the uptake of HSA and albumin-bound drugs. Doxorubicin is an FDA-approved chemotherapeutic agent that is effective against multiple cancers, but its clinical applicability has been hampered by its high toxicity levels. In this study, a doxorubicin-prodrug was developed that could independently and avidly bind HSA in circulation, called IPBA-Dox. We first developed and characterized IPBA-Dox and confirmed that it can bind albumin in vitro while retaining a potent cytotoxic effect. We then verified that it efficiently binds to HSA in circulation, leading to an improvement in the pharmacokinetic profile of the drug. In addition, we tested our prodrug for Cav-1 selectivity and found that it preferentially affects cells that express relatively higher levels of Cav-1 in vitro and in vivo. Moreover, we found that our compound was well tolerated in vivo at concentrations at which doxorubicin was lethal. Altogether, we have developed a doxorubicin-prodrug that can successfully bind HSA, retaining a strong cytotoxic effect that preferentially targets Cav-1 positive cells while improving the general tolerability of the drug., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)