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Objectives Renal replacement therapy (RRT) is increasingly adopted for critically ill patients diagnosed with acute kidney injury, but the optimal time for initiation remains unclear and prognosis is uncertain, leading to medical complexity, ethical conflicts, and decision dilemmas in intensive care unit (ICU) settings. This study aimed to develop a decision aid (DA) for the family surrogate of critically ill patients to support their engagement in shared decision-making process with clinicians. Methods Development of DA employed a systematic process with user-centered design (UCD) principle, which included: (i) competitive analysis: searched, screened, and assessed the existing DAs to gather insights for design strategies, developmental techniques, and functionalities; (ii) user needs assessment: interviewed family surrogates in our hospital to explore target user group's decision-making experience and identify their unmet needs; (iii) evidence syntheses: integrate latest clinical evidence and pertinent information to inform the content development of DA. Results The competitive analysis included 16 relevant DAs, from which we derived valuable insights using existing resources. User decision needs were explored among a cohort of 15 family surrogates, revealing four thematic issues in decision-making, including stuck into dilemmas, sense of uncertainty, limited capacity, and delayed decision confirmation. A total of 27 articles were included for evidence syntheses. Relevant decision-making knowledge on disease and treatment, as delineated in the literature sourced from decision support system or clinical guidelines, were formatted as the foundational knowledge base. Twenty-one items of evidence were extracted and integrated into the content panels of benefits and risks of RRT, possible outcomes, and reasons to choose. The DA was drafted into a web-based phototype using the elements of UCD. This platform could guide users in their preparation of decision-making through a sequential four-step process: identifying treatment options, weighing the benefits and risks, clarifying personal preferences and values, and formulating a schedule for formal shared decision-making with clinicians. Conclusions We developed a rapid prototype of DA tailored for family surrogate decision makers of critically ill patients in need of RRT in ICU setting. Future studies are needed to evaluate its usability, feasibility, and clinical effects of this intervention.
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Estado Terminal , Técnicas de Apoio para a Decisão , Família , Unidades de Terapia Intensiva , Terapia de Substituição Renal , Humanos , Terapia de Substituição Renal/métodos , Design Centrado no Usuário , Tomada de Decisões , Masculino , Feminino , Pessoa de Meia-IdadeRESUMO
Background: Upper limb balance is one of the important physical fitness parameters for all populations, especially overhead athletes like swimmers. Upper extremity star excursion balance test (UESEBT) is a comprehensive dynamic balance assessment, this study aims to explore the reliability and validity of UESEBT among adolescent swimmers. Methods: This cross-sectional study recruited 70 adolescent swimmers. All participants were required to complete UESEBT, upper quarter Y-balance test (UQYBT), maximal isometric strength (MIS) tests in upper limb, closed kinetic chain upper extremity stability test (CKCUEST), trunk flexor endurance test (TFET) and lateral trunk endurance test (LTET). The intra- and inter-operator reliability and the correlation of UESEBT with other physical performances were conducted. Results: For reliability, the intra- and inter-operator reliability of all directions and composite score were high-to-excellent (ICC = 0.706-1.000) among all participants. For validity, the UESEBT has a moderate-to-strong correlation with UQYBT (r = 0.42-0.72, p < 0.001), and a weak-to moderate one with CKCUEST (r = 0.25-0.42, p < 0.05). Furthermore, the UESEBT performance showed weak-to-moderate correlations with MIS (r = 0.24-0.44, p < 0.05). UESEBT was correlated to LTET (r = 0.24-0.33, p < 0.05) whereas no relationship was found with TFET. Conclusions: UESEBT was a reliable and valid tool to screen upper extremity dynamic balance among adolescent swimmers. UESEBT provides more detailed information in eight directions to assess the upper limb sport performance. Further study should explore the prediction ability of UESEBT for injury.
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PURPOSE: Diabetic cardiomyopathy (DCM), a common complication of diabetes mellitus and is characterized by myocardial hypertrophy and myocardial fibrosis. Pyrroloquinoline quinone (PQQ), a natural nutrient, exerts strong protection against various myocardial diseases. Pyroptosis, a type of inflammation-related programmed cell death, is vital to the development of DCM. However, the protective effects of PQQ against DCM and the associated mechanisms are not clear. This study aimed to investigate whether PQQ protected against DCM and to determine the underlying molecular mechanism. METHODS: Diabetes was induced in mice by intraperitoneal injection of streptozotocin, after which the mice were administered PQQ orally (10, 20, or 40 mg/kg body weight/day) for 12 weeks. AC16 human myocardial cells were divided into the following groups and treated accordingly: control (5.5 mmol/L glucose), high glucose (35 mmol/L glucose), and HG + PQQ groups (1 and 10 nmol/L PQQ). Cells were treated for 24 h. RESULTS: PQQ reduced myocardial hypertrophy and the area of myocardial fibrosis, which was accompanied by an increase in antioxidant function and a decrease in inflammatory cytokine levels. Moreover, myocardial hypertrophy-(ANP and BNP), myocardial fibrosis-(collagen I and TGF-ß1), and pyroptosis-related protein levels decreased in the PQQ treatment groups. Furthermore, PQQ abolished mitochondrial dysfunction and the activation of NF-κB/IκB, and decreased NLRP3 inflammation-mediated pyroptosis in AC16 cells under high-glucose conditions. CONCLUSION: PQQ improved DCM in diabetic mice by inhibiting NF-κB/NLRP3 inflammasome-mediated cell pyroptosis. Long-term dietary supplementation with PQQ may be greatly beneficial for the treatment of DCM. Diagram of the underlying mechanism of the effects of PQQ on DCM. PQQ inhibits ROS generation and NF-κB activation, which stimulates activation of the NLRP3 inflammasome and regulates the expression of caspase-1, IL-1ß, and IL-18. The up-regulated inflammatory cytokines trigger myocardial hypertrophy and cardiac fibrosis and promote the pathological process of DCM.
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Diabetes Mellitus Experimental , Cardiomiopatias Diabéticas , Animais , Cardiomegalia , Diabetes Mellitus Experimental/complicações , Cardiomiopatias Diabéticas/tratamento farmacológico , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/metabolismo , Fibrose , Glucose , Inflamassomos/metabolismo , Inflamação/complicações , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Cofator PQQ/metabolismo , Cofator PQQ/farmacologia , Cofator PQQ/uso terapêutico , Piroptose , Transdução de SinaisRESUMO
Metal oxide sensors face the challenge of high response and fast recovery at low operating temperatures for the detection of toxic and flammable hydrogen sulfide (H2S) gases. Herein, novel In-doped ZnO with a sunflower-like structure and tunable surface properties was rationally synthesized. The substitutional In atom in the ZnO crystal can dramatically enhance the concentration of oxygen vacancies (Ov), the In-ZnO sites are responsible for fast recovery, and the formation of sub-stable sulfide intermediates gives rise to the high response towards H2S. As a result, the response of the optimized 4In-ZnO sensor is 3538.36 to 50 ppm H2S at a low operating temperature of 110 °C, which is 106 times higher than that of pristine ZnO. Moreover, the response time and recovery time to 50 ppm H2S are 100 s and 27 s, respectively, with high selectivity and stability. First-principles calculations revealed that 4In-ZnO with rich Ov exhibited higher adsorption energy for the H2S molecule than pristine ZnO, resulting in effortless H2S detection. Our work lays the foundation for the rational design of highly sensitive gas sensors through precise doping of atoms in oxygen-rich vacancies in semiconductor materials.
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BACKGROUND: Somatosensory deficits and abnormal pain sensitivity are highly prevalent among stroke survivors, which negatively impacts their quality of life and recovery process. However, the factors for pressure pain threshold (PPT) and somatosensory abnormalities in post-stroke elderly remain unknown. The aim of this study was to explore the effects of age, side and other functional conditions, such as spasticity and motor functions, on PPT and sensory abnormalities among elderly after stroke. METHODS: The cross-sectional study finally included 43 post-stroke elderly aged over 60 and assessed the PPT of 14 bilateral muscles widely located in the whole body by using a digital force gage. Meanwhile, spasticity, motor function, joint pain and activity of daily living (ADL) were evaluated by the Modified Ashworth scale, Fugl-Meyer, and Barthel Index, respectively. All participants were divided into higher-aged and lower-aged groups based on the median age of all of them. RESULTS: Higher age tended to be associated with higher sensitivity but not significant except for one upper limb muscle, and the affected side showed significantly higher PPTs than the unaffected side in three out of seven muscles (p < 0.05). Furthermore, the somatosensory abnormalities in the affected side, particularly hypoalgesia, were more frequent in higher-aged than lower-aged patients in most assessed muscles. Meanwhile, patients with spasticity showed more increment of PPTs in affected muscles around the knee joint than patients without spasticity (p < 0.05). Patients with better motor functions, less joint pain and higher ADL performed less bilateral differences of PPTs than other patients in some muscles (p < 0.05). CONCLUSIONS: The age and side differences of mechanical pain sensitivity were found among post-stroke elderly. Older patients show higher sensitivity in both sides compared with the younger ones, and the affected side of the elder shows more somatosensory abnormalities, particularly hypoalgesia, than that of the younger ones. Post-stroke elderly in good functional conditions, such as normal muscle tone, better physical function and daily activities, and less joint pain, seems to have more equal pain sensitivity between both sides than those in poor conditions.
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Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Idoso , Humanos , Pessoa de Meia-Idade , Limiar da Dor , Qualidade de Vida , Estudos Transversais , Acidente Vascular Cerebral/complicações , Espasticidade Muscular/etiologia , Espasticidade Muscular/complicações , Artralgia , Resultado do TratamentoRESUMO
κ-carrageenases are members of the glycoside hydrolase family 16 (GH16) that hydrolyze sulfated galactans in red algae, known as κ-carrageenans. In this study, a novel κ-carrageenase gene from the marine bacterium Rhodopirellula sallentina SM41 (RsCgk) was discovered via the genome mining approach. There are currently no reports on κ-carrageenase from the Rhodopirellula genus, and RsCgk shares a low identity (less than 65%) with κ- carrageenase from other genera. The RsCgk was heterologously overexpressed in Escherichia coli BL21 and characterized for its enzymatic properties. RsCgk exhibited maximum activity at pH 7.0 and 40 °C, and 50% of its initial activity was retained after incubating at 30 °C for 2 h. More than 70% of its activity was maintained after incubation at pH 6.0-8.0 and 4 °C for 24 h. As a marine derived enzyme, RsCgk showed excellent salt tolerance, retaining full activity in 1.2 M NaCl, and the addition of NaCl greatly enhanced its thermal stability. Mass spectrometry analysis of the RsCgk hydrolysis products revealed that the enzyme had high degradation specificity and mainly produced κ-carrageenan disaccharide. Comparative molecular dynamics simulations revealed that the conformational changes of tunnel-forming loops under salt environments may cause the deactivation or stabilization of RsCgk. Our results demonstrated that RsCgk could be utilized as a potential tool enzyme for efficient production of κ-carrageenan oligosaccharides under high salt conditions.
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Tolerância ao Sal , Cloreto de Sódio , Carragenina/química , Bactérias/metabolismo , Glicosídeo Hidrolases/metabolismo , Proteínas de Bactérias/metabolismoRESUMO
As an important enzyme involved in the marine carbon cycle, alginate lyase has received extensive attention because of its excellent degradation ability on brown algae, which is widely utilized for alginate oligosaccharide preparation or bioethanol production. In comparison with endo-type alginate lyases (PL-5, PL-7, and PL-18 families), limited studies have focused on PL-17 family alginate lyases, especially for those with special characteristics. In this study, a novel PL-17 family alginate lyase, Aly23, was identified and cloned from the marine bacterium Pseudoalteromonas carrageenovora ASY5. Aly23 exhibited maximum activity at 35 °C and retained 48.93% of its highest activity at 4 °C, representing an excellent cold-adaptation property. Comparative molecular dynamics analysis was implemented to explore the structural basis for the cold-adaptation property of Aly23. Aly23 had a high substrate preference for poly ß-D-mannuronate and exhibited both endolytic and exolytic activities; its hydrolysis reaction mainly produced monosaccharides, disaccharides, and trisaccharides. Furthermore, the enzymatic hydrolyzed oligosaccharides displayed good antioxidant activities to reduce ferric and scavenge radicals, such as hydroxyl, ABTS+, and DPPH. Our work demonstrated that Aly23 is a promising cold-adapted biocatalyst for the preparation of natural antioxidants from brown algae.
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Antioxidantes/farmacologia , Oligossacarídeos/farmacologia , Polissacarídeo-Liases/metabolismo , Pseudoalteromonas/metabolismo , Antioxidantes/metabolismo , Dissacarídeos/metabolismo , Sequestradores de Radicais Livres/metabolismo , Sequestradores de Radicais Livres/farmacologia , Hidrólise , Simulação de Dinâmica Molecular , Monossacarídeos/metabolismo , Oligossacarídeos/metabolismo , Polissacarídeo-Liases/isolamento & purificação , Temperatura , Trissacarídeos/metabolismoRESUMO
A new megastimane sesquiterpenoid, cassianol A (1), and five known analogues (2-6) were isolated from the leaves extract of Cinnamomum cassia. Their structures were elucidated by extensive spectroscopic methods and single-crystal X-ray diffraction analyses. All the isolates were isolated from C. cassia for the first time. The anti-inflammatory activities of compounds 1-6 were evaluated against nitric oxide (NO) production in LPS-induced RAW 264.7 mouse macrophages.
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Cinnamomum aromaticum , Sesquiterpenos , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Cinnamomum aromaticum/química , Lipopolissacarídeos/farmacologia , Camundongos , Estrutura Molecular , Óxido Nítrico , Extratos Vegetais/química , Sesquiterpenos/farmacologiaRESUMO
A new pair of enantiomeric isoprenylated chromone derivatives, (±)-pestaloficiol X [(±)-1], along with a known compound pestaloficiol J (2), were isolated from the plant endophytic fungus Pestalotiopsis sp. The racemic mixture 1 was separated through chiral HPLC. The structures of new compounds (±)-1 were elucidated on the basis of extensive spectroscopic data and their absolute configurations were further configured through computational analysis of their electronic circular dichroism (ECD) spectra. Compound (+)-1 showed significant inhibitory potency against HL-60 and HEP-3B cell lines, with IC50 values of 1.35 ± 0.15 and 3.70 ± 0.33 µM, respectively, while compound (-)-1 showed significant inhibitory potency against HL-60 and HEP-3B cell lines, with IC50 values of 2.39 ± 0.26 and 2.99 ± 0.35 µM, respectively.
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Antineoplásicos , Pestalotiopsis , Antineoplásicos/farmacologia , Cromonas/química , Estrutura Molecular , EstereoisomerismoRESUMO
Some commonly used surfactants in cosmetic products raise concerns due to their skin-irritating effects and environmental contamination. Multifunctional, high-performance polymers are good alternatives to overcome these problems. In this study, agarose stearate (AS) with emulsifying, thickening, and gel properties was synthesized. Surfactant-free cosmetic formulations were successfully prepared from AS and carbomer940 (CBM940) mixed systems. The correlation of rheological parameter with skin feeling was determined to study the usability of the mixed systems in cosmetics. Based on rheological analysis, the surfactant-free cosmetic cream (SFC) stabilized by AS-carbomer940 showed shear-thinning behavior and strongly synergistic action. The SFC exhibited a gel-like behavior and had rheological properties similar to commercial cosmetic creams. Scanning electron microscope images proved that the AS-CBM940 network played an important role in SFC's stability. Oil content could reinforce the elastic characteristics of the AS-CBM940 matrix. The SFCs showed a good appearance and sensation during and after rubbing into skin. The knowledge gained from this study may be useful for designing surfactant-free cosmetic cream with rheological properties that can be tailored for particular commercial cosmetic applications. They may also be useful for producing medicine products with highly viscous or gel-like textures, such as some ointments and wound dressings.
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Resinas Acrílicas/síntese química , Cosméticos/síntese química , Excipientes/síntese química , Sefarose/análogos & derivados , Substâncias Viscoelásticas/síntese química , Resinas Acrílicas/química , Cosméticos/química , Excipientes/química , Géis , Humanos , Microscopia Eletrônica de Varredura , Reologia , Sefarose/síntese química , Sefarose/química , Creme para a Pele/síntese química , Creme para a Pele/química , Espectroscopia de Infravermelho com Transformada de Fourier , Tensoativos , Substâncias Viscoelásticas/químicaRESUMO
Agarose is a natural seaweed polysaccharide and widely used in the medicine, food, and biological fields because of its high gel strength, non-toxicity, and electrical neutrality. The sulfate group is one of the main charged groups that affect the performance of agarose. In the present study, a simple, eco-friendly, and efficient method was explored for agarose preparation. After desulfation with hydrogen peroxide (H2O2), the sulfate content of agar reached 0.21%. Together with gel strength, electroendosmosis, gelling and melting temperature, the indicators of desulfated agar met the standards of commercially available agarose. Notably, the desulfated agar can be used as an agarose gel electrophoresis medium to separate DNA molecules, and the separation effect is as good as that of commercially available agarose. Further, the H2O2 desulfation process was analyzed. The addition of a hydroxyl radical (HOâ¢) scavenger remarkably decreased the H2O2 desulfation rate, indicating that HO⢠has a certain role in agar desulfation. Sulfate content detection indicated that sulfur was removed from agar molecules in the form of sulfate ions (SO42-) and metal sulfate. The band absence at 850 cm-1 indicated that the sulfate groups at C-4 of D-galactose in sulfated galactan were eliminated.
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Ágar/química , Peróxido de Hidrogênio/química , Sefarose/química , Sulfatos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura de TransiçãoRESUMO
In this work, a non-toxic chitosan-based carrier was constructed via genipin activation and applied for the immobilization of tannase. The immobilization carriers and immobilized tannase were characterized using Fourier transform infrared spectroscopy and thermogravimetric analysis. Activation conditions (genipin concentration, activation temperature, activation pH and activation time) and immobilizations conditions (enzyme amount, immobilization time, immobilization temperature, immobilization pH, and shaking speed) were optimized. The activity and activity recovery rate of the immobilized tannase prepared using optimal activation and immobilization conditions reached 29.2 U/g and 53.6%, respectively. The immobilized tannase exhibited better environmental adaptability and stability. The immobilized tannase retained 20.1% of the initial activity after 12 cycles and retained 81.12% of residual activity after 30 days storage. The catechins composition analysis of tea extract indicated that the concentration of non-ester-type catechins, EGC and EC, were increased by 1758% and 807% after enzymatic treatment. Biological activity studies of tea extract revealed that tea extract treated with the immobilized tannase possessed higher antioxidant activity, higher inhibitory effect on α-amylase, and lower inhibitory effect on α-glucosidase. Our results demonstrate that chitosan activated with genipin could be an effective non-toxic carrier for tannase immobilization and enhancing biological activities of tea extract.
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Antioxidantes/farmacologia , Camellia sinensis , Hidrolases de Éster Carboxílico/metabolismo , Quitosana/química , Portadores de Fármacos , Inibidores de Glicosídeo Hidrolases/farmacologia , Iridoides/química , Extratos Vegetais/farmacologia , alfa-Amilases/antagonistas & inibidores , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Camellia sinensis/metabolismo , Hidrolases de Éster Carboxílico/química , Composição de Medicamentos , Estabilidade Enzimática , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/metabolismo , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/metabolismo , Temperatura , Fatores de Tempo , alfa-Amilases/metabolismoRESUMO
One new spirocyclic lactone, terreinlactone C (1), and one new benzopyran derivative, 2,2-dimethyl-3-hydroxychroman-6-aldehyde (2), were discovered from the fungus Aspergillus terreus. The chemical structures of compounds 1 and 2 were elucidated by detailedly analyzing NMR and HRESIMS data. Compound 1 is the first natural product with a 1-oxaspiro[4.5]decan-2-one ring system and a possible biogenetic pathway is proposed. Two compounds were tested for their cytotoxic activities against five human cancer cell lines.[Formula: see text].
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Benzopiranos , Lactonas , Aspergillus , Benzopiranos/farmacologia , Lactonas/farmacologia , Estrutura MolecularRESUMO
Due to their fascinating chemical structures and extensive pharmacological activities, polycyclic polyprenylated acylphloroglucinols(PPAPs) have become one of the current research hotspots of natural products. In particular, some of the PPAPs not only have novel non-traditional skeleton types, but also contain more unknown possible activities, which are of great significance for the development of lead compounds. The structure, source, biosynthetic pathway and pharmacological activities of PPAPs with non-traditio-nal skeleton types isolated and identified in recent years are reviewed, in order to provide references for further research on such compounds.
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Produtos Biológicos , Hypericum , Estrutura Molecular , FloroglucinolRESUMO
Although lanthanide tags, which have large anisotropic magnetic susceptibilities, have already been introduced to enrich NMR parameters by long-range pseudoconact shifts (PCSs) and residual dipolar couplings (RDCs) of proteins, their application to nucleotides has so far been limited to one previous report, due to the high affinities of lanthanides for the phosphodiester backbone of nucleotides and difficult organic synthesis. Herein, we report successful attachment of a lanthanide tag to a chemically synthesized oligonucleotide via a disulfide bond. NMR experiments reveal PCSs of up to 1â ppm and H-H RDCs of up to 8â Hz at 950â MHz. Although weaker magnetic alignment was achieved than with proteins, the paramagnetic data could be fitted to the known structure of the DNA, taking the mobility of the tag into account. While further rigidification of the tag is desirable, this tag could also be used to measure heteronuclear RDCs of 13 C,15 N-labeled chemically synthesized DNA and RNA.
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DNA/química , Elementos da Série dos Lantanídeos/química , Ressonância Magnética Nuclear Biomolecular , Oligonucleotídeos/química , RNA/química , DNA/síntese química , Modelos Moleculares , Estrutura Molecular , RNA/síntese químicaRESUMO
Gas sensors based on metal oxides semiconductor (MOS) have attracted extensive attention from both academic and industry. ZnO, as a typical MOS, exhibits potential applications in toxic gas detection, owning to its wide band gap, n-type transport characteristic and excellent electrical performance. Meanwhile, doping is an effective way to improve the sensing performance of ZnO materials. In this review, the effects of different types of doping on morphology, crystal structure, band gap and depletion layer of ZnO materials are comprehensively discussed. Theoretical analysis on the strategies for enhancing the sensing properties of ZnO is also provided. This review puts forward the reasonable insight for designing efficient n-type ZnO-based semiconductor oxide sensing materials.
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ß-Catenin has been implicated in major depressive disorder (MDD), which is associated with synaptic plasticity and dendritic arborization. MicroRNAs (miRNA) are small noncoding RNAs containing about 22 nucleotides and involved in a variety of physiological and pathophysiological process, but their roles in MDD remain largely unknown. Here, we investigated the expression and function of miRNAs in the mouse model of chronic social defeat stress (CSDS). The regulation of ß-catenin by selected miRNA was validated by silico prediction, target gene luciferase reporter assay, and transfection experiment in neurons. We demonstrated that the levels of miR-214-3p, which targets ß-catenin transcripts were significantly increased in the medial prefrontal cortex (mPFC) of CSDS mice. Antagomir-214-3p, a neutralizing inhibitor of miR-214-3p, increased the levels of ß-catenin and reversed the depressive-like behavior in CSDS mice. Meanwhile, antagomir-214-3p increased the amplitude of miniature excitatory postsynaptic current (mEPSC) and the number of dendritic spines in mPFC of CSDS mice, which may be related to the elevated expression of cldn1. Furthermore, intranasal administered antagomir-214-3p also significantly increased the level of ß-catenin and reversed the depressive-like behaviors in CSDS mice. These results may represent a new therapeutic target for MDD.
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Depressão/fisiopatologia , MicroRNAs/fisiologia , Estresse Psicológico/fisiopatologia , beta Catenina/fisiologia , Administração Intranasal , Animais , Antagomirs/administração & dosagem , Claudina-1/genética , Espinhas Dendríticas/efeitos dos fármacos , Espinhas Dendríticas/fisiologia , Depressão/etiologia , Depressão/genética , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Regulação da Expressão Gênica , Hipocampo/efeitos dos fármacos , Hipocampo/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/fisiopatologia , Estresse Psicológico/genética , beta Catenina/genéticaRESUMO
Alginate extracted from widely cultured brown seaweed can be hydrolyzed by alginate lyase to produce alginate oligosaccharides (AOS) with intriguing biological activities. Herein, a novel alginate lyase Aly1281 was cloned from marine bacterium Pseudoalteromonas carrageenovora ASY5 isolated from mangrove soil and found to belong to polysaccharide lyase family 7. Aly1281 exhibited maximum activity at pH 8.0 and 50 °C and have broad substrate specificity for polyguluronate and polymannuronate. Compared with other alginate lyases, Aly1281 exhibited high degradation specificity and mainly produced di-alginate oligosaccharides which displayed good antioxidant function to reduce ferric and scavenge radicals such as hydroxyl, ABTS+ and DPPH. Moreover, the catalytic activity and kinetic performance of Aly1281 were highly improved with the addition of salt, demonstrating a salt-activation property. A putative conformational structural feature of Aly1281 was found by MD simulation analysis for understanding the salt-activation effect.
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Polissacarídeo-Liases/isolamento & purificação , Pseudoalteromonas/enzimologia , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Concentração de Íons de Hidrogênio , Oligossacarídeos/metabolismo , Oligossacarídeos/farmacologia , Polissacarídeo-Liases/química , Polissacarídeo-Liases/metabolismo , Pseudoalteromonas/isolamento & purificação , Microbiologia do Solo , Especificidade por Substrato , TemperaturaRESUMO
Tannase is widely used in tea beverage processing because of its ability to catalyze the hydrolysis of hydrolysable tannins or gallic acid esters and effectively improve the quality of tea extracts through enzymatic extraction. A new thermophilic tannase was cloned from Aspergillus niger FJ0118 and characterized. The tannase exhibited an optimal reaction temperature of 80 °C and retained 89.6% of the initial activity after incubation at 60 °C for 2 h. The enzymatic extraction of green tea at high temperature (70 °C) for a short time (40 min) was devised on the basis of the superior thermal stability of tannase. The enzymatic reaction significantly increased the total polyphenol content of green tea extract from 137 g·kg-1 to 291 g·kg-1. The enzymatic reaction effectively degraded the ester catechins into non-ester catechins compared with the water extraction method. Results suggested that the thermally stable tannase exhibited potential applications in the enzymatic extraction of green tea beverage.
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Aspergillus niger/enzimologia , Hidrolases de Éster Carboxílico/química , Proteínas Fúngicas/química , Temperatura Alta , Chá/química , Estabilidade EnzimáticaRESUMO
A Cu2O/TiO2 p-n heterojunction composite was created via a facile, controllable, one-pot hydrothermal method based on cubic Cu2O and TiO2 nanoparticles in the presence of dioctyl sulfosuccinate sodium salt (AOT) surfactant. The TiO2 nanoparticles with an average edge length of â¼10.1 nm were uniformly distributed on the crystal surface of a Cu2O cube {100}. The photocatalytic performance of the composite was effectively tuned by controlling the amount of TiO2. The Cu2O/TiO2 (60 wt%, labeled as CT-60) exhibits the highest enhanced photocatalytic activity in hydrogen production with H2 evolution of 3002.5 µmol g-1. The yield remained around 92.6% after three cycles. Hydrogen production of the CT-60 is 103 and 8.5 fold higher than the cubic Cu2O and TiO2 nanoparticles, respectively. The improvement in photocatalytic performance could be attributed to the formation of p-n heterojunction. Furthermore, the interface effect of Cu2O and TiO2 caused a broader absorbance in the visible-light region and the lower recombination of photogenerated electron-hole pairs. It is believed that the Cu2O/TiO2 p-n heterojunction composites could provide an alternative method to design highly efficient photocatalysts for solar energy.