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BACKGROUND: Organellar genomes have become increasingly essential for studying genetic diversity, phylogenetics, and evolutionary histories of seaweeds. The order Dictyotales (Dictyotophycidae), a highly diverse lineage within the Phaeophyceae, is long-term characterized by a scarcity of organellar genome datasets compared to orders of the brown algal crown radiation (Fucophycidae). RESULTS: We sequenced the organellar genomes of Padina usoehtunii, a representative of the order Dictyotales, to investigate the structural and evolutionary differences by comparing to five other major brown algal orders. Our results confirmed previously reported findings that the rate of structural rearrangements in chloroplast genomes is higher than that in mitochondria, whereas mitochondrial sequences exhibited a higher substitution rate compared to chloroplasts. Such evolutionary patterns contrast with land plants and green algae. The expansion and contraction of the inverted repeat (IR) region in the chloroplast correlated with the changes in the number of boundary genes. Specifically, the size of the IR region influenced the position of the boundary gene rpl21, with complete rpl21 genes found within the IR region in Dictyotales, Sphacelariales and Ectocarpales, while the rpl21 genes in Desmarestiales, Fucales, and Laminariales span both the IR and short single copy (SSC) regions. The absence of the rbcR gene in the Dictyotales may indicate an endosymbiotic transfer from the chloroplast to the nuclear genome. Inversion of the SSC region occurred at least twice in brown algae. Once in a lineage only represented by the Ectocarpales in the present study and once in a lineage only represented by the Fucales. Photosystem genes in the chloroplasts experienced the strongest signature of purifying selection, while ribosomal protein genes in both chloroplasts and mitochondria underwent a potential weak purifying selection. CONCLUSIONS: Variations in chloroplast genome structure among different brown algal orders are evolutionarily linked to their phylogenetic positions in the Phaeophyceae tree. Chloroplast genomes harbor more structural rearrangements than the mitochondria, despite mitochondrial genes exhibiting faster mutation rates. The position and the change in the number of boundary genes likely shaped the IR regions in the chloroplast, and the produced structural variability is important mechanistically to create gene diversity in brown algal chloroplast.
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Evolução Molecular , Genoma de Cloroplastos , Phaeophyceae , Filogenia , Phaeophyceae/genética , Genoma Mitocondrial , Sequências Repetidas Invertidas/genética , Cloroplastos/genéticaRESUMO
The generation of cold molecules is an important topic in the field of cold atoms and molecules and has received relevant advanced research attention in ultracold chemistry, quantum computation, and quantum metrology. With a high atomic phase space density, optical dipole traps have been widely used to prepare, trap, and study cold molecules. In this work, Rb2 molecules were photoassociated in a magneto-optical trap to obtain a precise rovibrational spectrum, which provided accurate numerical references for the realization of multiple frequency photoassociation. By meeting the harsh requirements of photoassociation in optical dipole traps, the cold molecule photoassociation process was well explored, and different photoassociation resonances were simultaneously addressed in a single optical dipole trap. This method can be universally extended to simultaneously photoassociate cold molecules with different internal states or atomic species in a single optical dipole trap, thus advancing generous cold molecule studies such as cold molecule collision dynamics.
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Herein, by directly limiting the reaction space, an ingenious three-dimensional (3D) DNA walker (IDW) with high walking efficiency is developed for rapid and sensitive detection of miRNA. Compared with the traditional DNA walker, the IDW immobilized by the DNA tetrahedral nanostructure (DTN) brings stronger kinetic and thermodynamic favorability resulting from its improved local concentration and space confinement effect, accompanied by a quite faster reaction speed and much better walking efficiency. Once traces of target miRNA-21 react with the prelocked IDW, the IDW could be largely activated and walk on the interface of the electrode to trigger the cleavage of H2 with the assistance of Mg2+, resulting in the release of amounts of methylene blue (MB) labeled on H2 from the electrode surface and the obvious decrease of the electrode signal. Impressively, the IDW reveals a conversion efficiency as high as 9.33 × 108 in 30 min with a much fast reaction speed, which is at least five times beyond that of typical DNA walkers. Therefore, the IDW could address the inherent challenges of the traditional DNA walker easily: slow walking speed and low efficiency. Notably, the IDW as a DNA nanomachine was utilized to construct a sensitive sensing platform for rapid miRNA-21 detection with a limit of detection (LOD) of 19.8 aM and realize the highly sensitive assay of biomarker miRNA-21 in the total RNA lysates of cancer cell. The strategy thus helps in the design of a versatile nucleic acid conversion and signal amplification approach for practical applications in the areas of biosensing assay, DNA nanotechnology, and clinical diagnosis.
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Técnicas Biossensoriais , MicroRNAs , Nanoestruturas , MicroRNAs/genética , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , DNA/química , Nanoestruturas/química , Limite de DetecçãoRESUMO
To enhance the working quality of WLEDs, considerable efforts have been made to upgrade the thermal quenching resistance of existing phosphors or design new anti-thermal quenching (ATQ) phosphors. Developing a new phosphate matrix material with special structural features has great importance for the fabrication of ATQ phosphors. By phase relationship and composition analysis, we have prepared a novel compound Ca3.6In3.6(PO4)6 (CIP). Coupling ab initio and Rietveld refinement techniques, the novel structure of CIP with partly vacant cationic positions was solved. Taking this unique compound as the host and using the inequivalent substitution of Dy3+ for Ca2+, a series of C1-xIP:Dy3+ rice-white emitting phosphors were successfully developed. When the temperature was raised to 423 K, the emission intensity of C1-xIP:xDy3+ (x = 0.01, 0.03, and 0.05) increased to 103.8%, 108.2%, and 104.5% of the original intensity at 298 K, respectively. Except for the strong bonding network and inherent cationic vacancy in the lattice, the ATQ property of the C1-xIP:Dy3+ phosphors is mainly attributed to the generation of interstitial oxygen from the substitution of unequal ions, which releases electrons with the thermal stimulus, causing anomalous emission. Finally, we have explored the quantum efficiency of C1-xIP:0.03Dy3+ phosphor and the working performance of PC-WLED prepared with C1-xIP:0.03Dy3+ phosphor and 365 nm chip. The research work sheds light on the relationship between lattice defects and thermal stability, and meanwhile offers a new strategy for the development of ATQ phosphors.
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BACKGROUND: In the trauma center wards, it is not unusual for patients to have sleep disorders, especially patients with an acute injury. Meanwhile, there is substantial evidence that sleep disorder is a predictor of depression and is an important feature of posttraumatic stress disorder. METHODS: All orthopedic trauma patients confined in a trauma ward in West China Hospital of Sichuan University between April 2018 and July 2019 were included in this retrospective study. Patients with mental impairment or craniocerebral injuries were excluded from the study. Basic demographic data and the Injury Severity Score (ISS) classification based on medical records were collected. The Pittsburgh sleep quality index (PSQI) was used to evaluate sleep quality, the visual analog scale (VAS) was used to evaluate physical pain, and the Barthel Index (BI) was used to evaluate activities of daily living (ADL). Univariate linear regression analysis and multivariate linear regression analysis were used to identify independently related factors. RESULTS: The average PSQI score was 6.3 (± 4.0). A total of 581 (51.4%) patients had a PSQI score > 5, indicating the presence of sleep disorders. The PSQI score was > 10 in 174 (15.4%) patients. Univariate statistical analysis showed that age, sex, education, ADL, and ISS classification were associated with increased PSQI scores. Marital status and pain were not associated with increased PSQI scores. When we used multivariate analysis to control for confounding variables, sex, ADL, and ISS classification remained independently associated with PSQI (P = 0.002, < 0.000, and 0.002, respectively). CONCLUSIONS: In our study, sleep disorders were common (51.4% with PSQI > 5) and serious (15.4% with PSQI > 10) in patients with traumatic orthopedic injury. The following factors were closely associated with sleep disorders: sex, ADL, and ISS classification. Moreover, age and educational attainment have an independent impact on sleep quality. Unexpectedly, the VAS score for pain was not independently associated with the seriousness of sleep quality, which may be related to preemptive and multimodal analgesia. Further studies are required to clarify this ambiguity.
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Sistema Musculoesquelético/lesões , Transtornos do Sono-Vigília/epidemiologia , Adulto , Idoso , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Inquéritos e Questionários , Centros de TraumatologiaRESUMO
Rice false smut, caused by the fungal pathogen Villosiclava virens, is one of the most important rice diseases in the world. Previous studies reported that the pathogen has less number of cell wall-degraded genes and attacks dominantly rice stamen filaments and extends intercellularly. To reveal why the fungus infects plant stamen filaments, inoculation test on barley was carried out with the similar protocol to rice. The experimental results showed that the fungus could penetrate quickly into barley stamen filaments and extends both intracellularly and intercellularly, usually resulting in severe damage of the stamen filament tissues. It also attacked young barley lodicules and grew intercellularly by chance. The light microscopic observations found that the epidermal and cortex cells in barley stamen filaments arranged loosely with very thick cell walls and large cell gaps. Cellulose microfibrils in barley stamen filament cell walls arranged very sparsely so that the cell walls looked like transparent. The cell walls were very soft and flexible, and often folded. However, V. virens extended dominantly in the noncellulose regions and seemed never to degrade microfibrils in barley and rice cell walls. This suggested that the unique structures of rice and barley stamen filaments should be fit for their function of elongation in anthesis, and also endow with the susceptibility to the fungus, V. virens.
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Parede Celular/ultraestrutura , Flores , Hordeum , Hypocreales/ultraestrutura , Oryza , Flores/microbiologia , Flores/ultraestrutura , Hordeum/microbiologia , Hordeum/ultraestrutura , Microscopia , Microscopia Eletrônica de Transmissão , Oryza/microbiologia , Oryza/ultraestrutura , Doenças das Plantas/microbiologiaRESUMO
The insulin secretory response by pancreatic beta-cells to an acute "square wave" stimulation by glucose is characterized by a first phase that occurs promptly after exposure to glucose, followed by a decrease to a nadir, and a prolonged second phase. The first phase of release is due to the ATP-sensitive K(+) (K(ATP)) channel-dependent (triggering) pathway that increases [Ca(2+)](i) and has been thought to discharge the granules from a "readily releasable pool." It follows that the second phase entails the preparation of granules for release, perhaps including translocation and priming for fusion competency before exocytosis. The pathways responsible for the second phase include the K(ATP) channel-dependent pathway because of the need for elevated [Ca(2+)](i) and additional signals from K(ATP) channel-independent pathways. The mechanisms underlying these additional signals are unknown. Current hypotheses include increased cytosolic long-chain acyl-CoA, the pyruvate-malate shuttle, glutamate export from mitochondria, and an increased ATP/ADP ratio. In mouse islets, the beta-cell contains some 13,000 granules, of which approximately 100 are in a "readily releasable" pool. Rates of granule release are slow, e.g., one every 3 s, even at the peak of the first phase of glucose-stimulated release. As both phases of glucose-stimulated insulin secretion can be enhanced by agents such as glucagon-like peptide 1, which increases cyclic AMP levels and protein kinase A activity, or acetylcholine, which increases diacylglycerol levels and protein kinase C activity, a single "readily releasable pool" hypothesis is an inadequate explanation for insulin secretion. Multiple pools available for rapid release or rapid conversion of granules to a rapidly releasable state are required.
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Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Vesículas Secretórias/metabolismo , Animais , Secreção de InsulinaRESUMO
The glucagon-releasing pancreatic alpha-cells are electrically excitable cells but the signal transduction leading to depolarization and secretion is not well understood. To clarify the mechanisms we studied [Ca(2+)](i) and membrane potential in individual mouse pancreatic alpha-cells using fluorescent indicators. The physiological secretagogue l-adrenaline increased [Ca(2+)](i) causing a peak, which was often followed by maintained oscillations or sustained elevation. The early effect was due to mobilization of Ca(2+) from the endoplasmic reticulum (ER) and the late one to activation of store-operated influx of the ion resulting in depolarization and Ca(2+) influx through voltage-dependent L-type channels. Consistent with such mechanisms, the effects of adrenaline on [Ca(2+)](i) and membrane potential were mimicked by inhibitors of the sarco(endo)plasmic reticulum Ca(2+) ATPase. The alpha-cells express ATP-regulated K(+) (K(ATP)) channels, whose activation by diazoxide leads to hyperpolarization. The resulting inhibition of the voltage-dependent [Ca(2+)](i) response to adrenaline was reversed when the K(ATP) channels were inhibited by tolbutamide. However, tolbutamide alone rarely affected [Ca(2+)](i), indicating that the K(ATP) channels are normally closed in mouse alpha-cells. Glucose, which is the major physiological inhibitor of glucagon secretion, hyperpolarized the alpha-cells and inhibited the late [Ca(2+)](i) response to adrenaline. At concentrations as low as 3mM, glucose had a pronounced stimulatory effect on Ca(2+) sequestration in the ER amplifying the early [Ca(2+)](i) response to adrenaline. We propose that adrenaline stimulation and glucose inhibition of the alpha-cell involve modulation of a store-operated current, which controls a depolarizing cascade leading to opening of L-type Ca(2+) channels. Such a control mechanism may be unique among excitable cells.
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Canais de Cálcio/metabolismo , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Glucagon/metabolismo , Ilhotas Pancreáticas/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Animais , Sinalização do Cálcio , Retículo Endoplasmático/efeitos dos fármacos , Epinefrina/farmacologia , Glucose/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Camundongos , Canais de Potássio/fisiologia , Vasoconstritores/farmacologiaRESUMO
Stimulation of glucagon release and inhibition of insulin secretion from the islets of Langerhans are important for the blood-glucose-elevating effect of adrenaline. The mechanisms by which adrenaline accomplishes these actions may involve direct effects and indirect ones mediated by altered release of other islet hormones. In the present study we investigated how adrenaline affects the cytoplasmic Ca2+ concentration, which controls glucagon secretion from the pancreatic alpha-cell. The studies were performed on isolated mouse alpha-cells, which were identified by immunocytochemistry. The adrenaline effects consisted of initial mobilisation of intracellular Ca2+, accompanied by voltage-dependent influx of the ion. Part of the effect could be attributed to beta-adrenoceptor activation, as it was mimicked by the rise in cAMP and inhibited by the antagonist propranolol as well as the protein kinase A inhibitor adenosine 3',5'-cyclic monophosphorothioate Rp-isomer. alpha1-Adrenoceptors were also involved, since the antagonists phentolamine and prazosin completely abolished the effects of adrenaline. Experiments with clonidine and yohimbine gave little evidence of a role of alpha2-adrenoceptors. The results indicate that alpha1- and beta-adrenoceptors on the alpha-cells mediate adrenaline-stimulated glucagon secretion. The complete inhibition of the adrenaline response after blocking alpha1-adrenoceptors indicates an interaction with the beta-adrenergic pathway.
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Epinefrina/fisiologia , Glucagon/metabolismo , Ilhotas Pancreáticas/metabolismo , Receptores Adrenérgicos alfa 1/fisiologia , Receptores Adrenérgicos beta/fisiologia , Agonistas de Receptores Adrenérgicos alfa 1 , Antagonistas de Receptores Adrenérgicos alfa 1 , Antagonistas Adrenérgicos alfa/farmacologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Glicemia/metabolismo , Cálcio/metabolismo , Epinefrina/antagonistas & inibidores , Epinefrina/farmacologia , Técnicas In Vitro , Ilhotas Pancreáticas/efeitos dos fármacos , Camundongos , Receptores Adrenérgicos beta/efeitos dos fármacos , Fatores de TempoRESUMO
Nutrients that induce biphasic insulin release, such as glucose and leucine, provide acetyl-CoA and anaplerotic input in the beta-cell. The first phase of release requires increased ATP production leading to increased intracellular Ca(2+) concentration ([Ca(2+)](i)). The second phase requires increased [Ca(2+)](i) and anaplerosis. There is strong evidence to indicate that the second phase is due to augmentation of Ca(2+)-stimulated release via the K(ATP) channel-independent pathway. To test whether the phenomenon of time-dependent potentiation (TDP) has similar properties to the ATP-sensitive K(+) channel-independent pathway, we monitored the ability of different agents that provide acetyl-CoA and anaplerotic input or both of these inputs to induce TDP. The results show that anaplerotic input is sufficient to induce TDP. Interestingly, among the agents tested, the nonsecretagogue glutamine, the nonhydrolyzable analog of leucine aminobicyclo[2.2.1]heptane-2-carboxylic acid, and succinic acid methyl ester all induced TDP, and all significantly increased alpha-ketoglutarate levels in the islets. In conclusion, anaplerosis that enhances the supply and utilization of alpha-ketoglutarate in the tricarboxylic acid cycle appears to play an essential role in the generation of TDP.
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Ciclo do Ácido Cítrico/fisiologia , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Mitocôndrias/metabolismo , Transdução de Sinais/fisiologia , Acetilcoenzima A/metabolismo , Aminoácidos/metabolismo , Aminoácidos Cíclicos/farmacologia , Análise de Variância , Animais , Cálcio/metabolismo , Ativação Enzimática/efeitos dos fármacos , Glucose/metabolismo , Técnicas In Vitro , Secreção de Insulina , Ácidos Cetoglutáricos/metabolismo , Masculino , Mitocôndrias/efeitos dos fármacos , Ratos , Ratos Wistar , Estimulação Química , Regulação para CimaRESUMO
Leucine and glutamine were used to elicit biphasic insulin release in rat pancreatic islets. Leucine did not mimic the full biphasic response of glucose. Glutamine was without effect. However, the combination of the two did mimic the biphasic response. When the ATP-sensitive K+ (KATP) channel-independent pathway was studied in the presence of diazoxide and KCl, leucine and its nonmetabolizable analog 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH) both stimulated insulin secretion to a greater extent than glucose. Glutamine and dimethyl glutamate had no effect. Because the only known action of BCH is stimulation of glutamate dehydrogenase, this is sufficient to develop the full effect of the KATP channel-independent pathway. Glucose, leucine, and BCH had no effect on intracellular citrate levels. Leucine and BCH both decreased glutamate levels, whereas glucose was without effect. Glucose and leucine decreased palmitate oxidation and increased esterification. Strikingly, BCH had no effect on palmitate oxidation or esterification. Thus BCH activates the KATP channel-independent pathway of glucose signaling without raising citrate levels, without decreasing fatty acid oxidation, and without mimicking the effects of glucose and leucine on esterification. The results indicate that increased flux through the TCA cycle is sufficient to activate the KATP channel-independent pathway.