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1.
Plant Cell ; 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39235115

RESUMEN

Multiple plant hormones, including strigolactone (SL), play key roles in regulating flowering time. The Arabidopsis (Arabidopsis thaliana) DWARF14 (AtD14) receptor perceives SL and recruits F-box protein MORE AXILLARY GROWTH2 (MAX2) and the SUPPRESSOR OF MAX2-LIKE (SMXL) family proteins. These interactions lead to the degradation of the SMXL repressor proteins, thereby regulating shoot branching, leaf shape, and other developmental processes. However, the molecular mechanism by which SL regulates plant flowering remains elusive. Here, we demonstrate that intact strigolactone biosynthesis and signaling pathways are essential for normal flowering in Arabidopsis. Loss-of-function mutants in both SL biosynthesis (max3) and signaling (Atd14 and max2) pathways display earlier flowering, whereas the repressor triple mutant smxl6/7/8 (s678) exhibits the opposite phenotype. Retention of AtD14 in the cytoplasm leads to its inability to repress flowering. Moreover, we show that nuclear-localized AtD14 employs dual strategies to enhance the function of the AP2 transcription factor TARGET OF EAT1 (TOE1). AtD14 directly binds to TOE1 in an SL-dependent manner and stabilizes it. In addition, AtD14-mediated degradation of SMXL7 releases TOE1 from the repressor protein, allowing it to bind to and inhibit the FLOWERING LOCUS T (FT) promoter. This results in reduced FT transcription and delayed flowering. In summary, AtD14 perception of SL enables the transcription factor TOE1 to repress flowering, providing insights into hormonal control of plant flowering.

2.
Neural Comput ; 36(9): 1912-1938, 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39106463

RESUMEN

Adam-type algorithms have become a preferred choice for optimization in the deep learning setting; however, despite their success, their convergence is still not well understood. To this end, we introduce a unified framework for Adam-type algorithms, termed UAdam. It is equipped with a general form of the second-order moment, which makes it possible to include Adam and its existing and future variants as special cases, such as NAdam, AMSGrad, AdaBound, AdaFom, and Adan. The approach is supported by a rigorous convergence analysis of UAdam in the general nonconvex stochastic setting, showing that UAdam converges to the neighborhood of stationary points with a rate of O(1/T). Furthermore, the size of the neighborhood decreases as the parameter ß1 increases. Importantly, our analysis only requires the first-order momentum factor to be close enough to 1, without any restrictions on the second-order momentum factor. Theoretical results also reveal the convergence conditions of vanilla Adam, together with the selection of appropriate hyperparameters. This provides a theoretical guarantee for the analysis, applications, and further developments of the whole general class of Adam-type algorithms. Finally, several numerical experiments are provided to support our theoretical findings.

3.
Neural Netw ; 179: 106514, 2024 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-39024708

RESUMEN

Shuffling-type gradient method is a popular machine learning algorithm that solves finite-sum optimization problems by randomly shuffling samples during iterations. In this paper, we explore the convergence properties of shuffling-type gradient method under mild assumptions. Specifically, we employ the bandwidth-based step size strategy that covers both monotonic and non-monotonic step sizes, thereby providing a unified convergence guarantee in terms of step size. Additionally, we replace the lower bound assumption of the objective function with that of the loss function, thereby eliminating the restrictions on the variance and the second-order moment of stochastic gradient that are difficult to verify in practice. For non-convex objectives, we recover the last iteration convergence of shuffling-type gradient algorithm with a less cumbersome proof. Meanwhile, we also establish the convergence rate for the minimum iteration of gradient norms. Under the Polyak-Lojasiewicz (PL) condition, we prove that the function value of last iteration converges to the lower bound of the objective function. By selecting appropriate boundary functions, we further improve the previous sublinear convergence rate results. Overall, this paper contributes to the understanding of shuffling-type gradient method and its convergence properties, providing insights for optimizing finite-sum problems in machine learning. Finally, numerical experiments demonstrate the efficiency of shuffling-type gradient method with bandwidth-based step size and validate our theoretical results.

4.
Neurosci Lett ; 836: 137897, 2024 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-39004114

RESUMEN

The efficacy of vitamin C in age-related hearing loss, i.e., presbycusis, remains debatable. On a separate note, inflammation induced by the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is involved in the progression of presbycusis. In this study, we investigated the effect of vitamin C on male C57BL/6 mice's presbycusis and NLRP3 inflammasome. The results showed that vitamin C treatment improved hearing, reduced the production of inflammatory factors, inhibited NLRP3 inflammasome activation, and decreased cytosolic mitochondrial DNA (mtDNA) in the C57BL/6 mouse cochlea, inferior colliculus, and auditory cortex. According to this study, vitamin C protects auditory function in male C57BL/6 presbycusis mice through reducing mtDNA release, inhibiting the NLRP3 inflammasome activation in the auditory pathway. Our study provides a theoretical basis for applying vitamin C to treat presbycusis.


Asunto(s)
Ácido Ascórbico , ADN Mitocondrial , Inflamasomas , Ratones Endogámicos C57BL , Proteína con Dominio Pirina 3 de la Familia NLR , Presbiacusia , Animales , Masculino , Ácido Ascórbico/farmacología , Ácido Ascórbico/uso terapéutico , Ácido Ascórbico/administración & dosificación , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Presbiacusia/metabolismo , Presbiacusia/prevención & control , Inflamasomas/metabolismo , Inflamasomas/efectos de los fármacos , ADN Mitocondrial/metabolismo , ADN Mitocondrial/efectos de los fármacos , Ratones , Cóclea/efectos de los fármacos , Cóclea/metabolismo , Corteza Auditiva/efectos de los fármacos , Corteza Auditiva/metabolismo
5.
Inorg Chem ; 63(24): 11459-11469, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38842950

RESUMEN

The performance of covalent-organic frameworks (COFs) for the photocatalytic extraction of uranium is greatly limited by the number of adsorption sites. Herein, inspired by electronegative redox reactions, we designed a nitrogen-oxygen rich pyrazine connected COF (TQY-COF) with multiple redox sites as a platform for extracting uranium via combining superaffinity and enhanced photoinduction. The preorganized bisnitrogen-bisoxygen donor configuration on TQY-COF is entirely matched with the typical geometric coordination of hexavalent uranyl ions, which demonstrates high affinity (tetra-coordination). In addition, the presence of the carbonyl group and pyrazine ring effectively stores and controls electron flow, which efficaciously facilitates the separation of e-/h+ and enhances photocatalytic performance. The experimental results show that TQY-COF removes up to 99.8% of uranyl ions from actual uranium mine wastewater under the light conditions without a sacrificial agent, and the separation coefficient reaches 1.73 × 106 mL g-1 in the presence of multiple metal ions, which realizes the precise separation in the complex environment. Importantly, DFT calculations further elucidate the coordination mechanism of uranium and demonstrate the necessity of the presence of N/O atoms in the photocatalytic adsorption of uranium.

6.
Anal Chem ; 96(8): 3553-3560, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38362858

RESUMEN

Lead halide perovskite nanocrystals with excellent photophysical properties are promising electrochemiluminescence (ECL) candidates, but their poor stability greatly restricts ECL applications. Herein, hydrogen-bonded cocrystal-encapsulated CsPbBr3 perovskite nanocrystals (PeNCs@NHS-M) were synthesized by using PeNCs as nuclei for inducing the crystallization of melamine (M) and N-hydroxysuccinimide (NHS). The as-synthesized composite exhibits multiplicative ECL efficiencies (up to 24-fold that of PeNCs) without exogenous coreactants and with excellent stability in the aqueous phase. The enhanced stability can be attributed to the well-designed heterostructure of the PeNCs@NHS-M composite, which benefits from both moiety passivation and protection of the peripheral cocrystal matrix. Moreover, the heterostructure with covalent linkage facilitates charge transfer between PeNCs and NHS-M cocrystals, realizing effective ECL emission. Meanwhile, the NHS and M components act as coreactants for PeNCs, shortening the electron-transport distance and resulting in a significant increase in the ECL signal. Furthermore, by taking advantage of the specific binding effect between NHS-M and uranyl (UO22+), an ECL system with both a low detection limit (1 nM) and high selectivity for monitoring UO22+ in mining wastewater is established. The presence of UO22+ disrupted the charge-transfer effect within PeNCs@NHS-M, weakening the ECL signals. This work provides an efficient design strategy for obtaining stable and efficient ECLs from perovskite nanocrystals, offering a new perspective for the discovery and application of perovskite-based ECL systems.

7.
Small ; 20(25): e2310672, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38229539

RESUMEN

At present, poor stability and carrier transfer efficiency are the main problems that limit the development of perovskite-based photoelectric technologies. In this work, hydrogen-bonded cocrystal-coated perovskite composite (PeNCs@NHS-M) is easily obtained by inducing rapid crystallization of melamine (M) and N-hydroxysuccinimide (NHS) with PeNCs as the nuclei. The outer NHS-M cocrystal passivates the undercoordinated lead atoms by forming covalent bonds, thereby greatly reducing the trap density while maintaining good structure stability for perovskite nanocrystals. Moreover, benefiting from the interfacial covalent band linkage and long-range ordered structures of cocrystals, the charge transfer efficiency is effectively enhanced and PeNCs@NHS-M displays superior photoelectric performance. Based on the excellent photoelectric performance and abundant active sites of PeNCs@NHS-M, photocatalytic reduction of uranium is realized. PeNCs@NHS-M exhibits U(VI) reduction removal capability of up to 810.1 mg g-1 in the presence of light. The strategy of cocrystals trapping perovskite nanocrystals provides a simple synthesis method for composites and opens up a new idea for simultaneously improving the stability and photovoltaic performance of perovskite.

9.
Neural Netw ; 165: 830-845, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37418864

RESUMEN

Stochastic momentum methods are widely used to solve stochastic optimization problems in machine learning. However, most of the existing theoretical analyses rely on either bounded assumptions or strong stepsize conditions. In this paper, we focus on a class of non-convex objective functions satisfying the Polyak-Lojasiewicz (PL) condition and present a unified convergence rate analysis for stochastic momentum methods without any bounded assumptions, which covers stochastic heavy ball (SHB) and stochastic Nesterov accelerated gradient (SNAG). Our analysis achieves the more challenging last-iterate convergence rate of function values under the relaxed growth (RG) condition, which is a weaker assumption than those used in related work. Specifically, we attain the sub-linear rate for stochastic momentum methods with diminishing stepsizes, and the linear convergence rate for constant stepsizes if the strong growth (SG) condition holds. We also examine the iteration complexity for obtaining an ϵ-accurate solution of the last-iterate. Moreover, we provide a more flexible stepsize scheme for stochastic momentum methods in three points: (i) relaxing the last-iterate convergence stepsize from square summable to zero limitation; (ii) extending the minimum-iterate convergence rate stepsize to the non-monotonic case; (iii) expanding the last-iterate convergence rate stepsize to a more general form. Finally, we conduct numerical experiments on benchmark datasets to validate our theoretical findings.


Asunto(s)
Algoritmos , Aprendizaje Automático , Movimiento (Física)
10.
Environ Sci Pollut Res Int ; 30(30): 75104-75115, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37213020

RESUMEN

As the core of pollution prevention and management, accurate PM2.5 concentration prediction is crucial for human survival. However, due to the nonstationarity and nonlinearity of PM2.5 concentration data, the accurate prediction for PM2.5 concentration remains a challenge. In this study, a PM2.5 concentration prediction method using weighted complementary ensemble empirical mode decomposition with adaptive noise (WCEEMDAN) and improved long and short-term memory (ILSTM) neural network is proposed. Firstly, a novel WCEEMDAN method is proposed to correctly identify the non-stationary and non-linear characteristics and divide the PM2.5 sequences into various layers. Through the correlation analysis with PM2.5 data, these sub-layers are given different weights. Secondly, the adaptive mutation particle swarm optimization (AMPSO) algorithm is developed to obtain the main hyperparameters of the long short-term memory network (LSTM) neural network, improving the prediction accuracy of PM2.5 concentration. The optimization convergence speed and accuracy are improved by adjusting the inertia weight and introducing the mutation mechanism to enhance the global optimization ability. Finally, three groups of PM2.5 concentration data are utilized to verify the effectiveness of the proposed model. Compared with other methods, the experimental results demonstrate the superiority of the proposed model. The source code can be downloaded from https://github.com/zhangli190227/WCEENDAM-ILSTM .


Asunto(s)
Algoritmos , Redes Neurales de la Computación , Humanos , Contaminación Ambiental , Mutación , Material Particulado
11.
PeerJ ; 11: e15203, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37090107

RESUMEN

Background: Sterol-regulatory element-binding protein 1 (SREBP1) is a transcription factor involved in lipid metabolism that is encoded by sterol regulatory element binding transcription factor 1(SREBF1). SREBP1 overexpression is associated with the progression of several human tumors; however, the role of SREBP1 in head and neck squamous cell carcinoma (HNSC) remains unclear. Methods: SREBF1 expression in pan-cancer was analyzed using the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) data, and the association between SREBF1 expression and clinical characteristics of HNSC patients was examined using the UALCAN database. Enrichment analysis of SREBF1-related genes was performed using the Cluster Profiler R package. TCGA database was used to investigate the relationship between immune cell infiltration and SREBF1 expression. CCK-8, flow cytometry, and wound healing assays were performed to investigate the effect of SREBF1 knockdown on the proliferation and migration of HNSC cells. Results: SREBF1 was significantly upregulated in several tumor tissues, including HNSC, and SREBF1 overexpression was positively correlated with sample type, cancer stage, tumor grade, and lymph node stage in HNSC patients. Gene enrichment analysis revealed that SREBF1 is associated with DNA replication and homologous recombination. SREBF1 upregulation was positively correlated with the infiltration of cytotoxic cells, B cells, T cells, T helper cells, and NK CD56 bright cells in HNSC. Knockdown of SREBF1 inhibited the proliferation and migration of HNSC cells (Hep2 and TU212) and induced apoptosis by downregulating the expression of steroidogenic acute regulatory protein-related lipid transfer 4 (STARD4). Conclusions: SREBF1 may promote HNSC proliferation, migration and inhibit apoptosis by upregulating STARD4 and affecting the level of immune cell infiltration.


Asunto(s)
Neoplasias de Cabeza y Cuello , Factores de Transcripción , Humanos , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/genética , Proliferación Celular/genética , Esteroles
12.
Neuroscience ; 517: 84-95, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36702373

RESUMEN

Melatonin supplementation has been shown to delay age-related hearing loss (ARHL) progression. Previously, melatonin was found to inhibit neuronal mitochondrial DNA (mtDNA) release, as well as inhibit cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling, thereby delaying the onset of central nervous system diseases. Therefore, we hypothesized that melatonin may delay the progression of hearing loss in the C57BL/6J presbycusis mouse model by inhibiting cGAS-STING signaling in the auditory pathway. Oral melatonin at 10 mg/kg/d was administered to 3-month-old C57BL/6J mice until 12 months of age. The auditory brainstem response (ABR) threshold was used to assess their hearing ability. By real-time polymerase chain reaction and Western blot analysis, the levels of cytosolic mtDNA, cGAS/STING, and cytokines were examined in the mouse cochlea, inferior colliculus, and auditory cortex. We found that the 12-month-old control mice exhibited significant hearing loss, increased cytosolic mtDNA, increased expression of inflammatory factors TNF-α, IL-6, IFN-ß, Cxcl10, and Ifit3, up-regulated cGAS and STING expression, and enhanced interferon regulatory factor 3 (IRF3) phosphorylation in the C57BL/6J mouse cochlea, inferior colliculus, and auditory cortex. Melatonin treatment significantly improved hearing, decreased cytosolic mtDNA, suppressed the expression of inflammatory cytokines TNF-α, IL-6, IFN-ß, Ifit3, and Cxcl10, down-regulated cGAS and STING expression, and attenuated IRF3 phosphorylation in the C57BL/6J mouse cochlea, inferior colliculus, and auditory cortex. This study suggested that melatonin had a protective effect on auditory function in the C57BL/6J presbycusis mouse model, which may be mediated through reducing mtDNA release, inhibiting the cGAS-STING signaling pathway in the auditory pathway.


Asunto(s)
Sordera , Melatonina , Presbiacusia , Ratones , Animales , Interferones , Melatonina/farmacología , Ratones Endogámicos C57BL , Factor de Necrosis Tumoral alfa , Interleucina-6 , Transducción de Señal , Nucleotidiltransferasas/genética , Citocinas , ADN Mitocondrial/metabolismo
13.
Small ; 19(10): e2206814, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36642794

RESUMEN

Gel polymer electrolyte (GPE) in quasi-solid state Zn-air battery (QSZAB) will release alkali during cycling, resulting in gradual dehydration of GPE, corrosion of Zn electrode, Zn dendrites growth, and therefore inferior performance. Here, hollow Sn microspheres are prepared on Zn substrate by the technique of colloidal self-assembly. The inner surfaces of hollow Sn microspheres are modified by 2-hydroxypropyl-ß-cyclodextrin (hollow Sn-inner HPßCD) to regulate the released alkali at GPE|anode interface. The hollow Sn-inner HPßCD can lessen the leakage of released alkali, make stored alkali diffuse back to GPE during the charging process, and mitigate the loss of soluble Zn(OH)4 2- to suppress Zn dendrites growth. Resultantly, GPE in QSZAB with hollow Sn-inner HPßCD exhibits a high retention capacity for alkaline solution. The cell also exhibits a long cyclic lifespan of 127 h due to the effective regulation of released alkali, which outperforms QSZAB without hollow Sn-inner HPßCD by 7.94 times. This work rivets the regulation of released alkali at GPE|anode interface, providing new insight to improve QSZABs' performance.

14.
Front Psychol ; 13: 870318, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35936348

RESUMEN

Creativity and innovation have significantly increased in the past years. Amabile and Pratt were the leading proponents of creativity who integrated a dynamic componential model of creativity and innovation in organizations. The present study discusses the concept of innovative behavior within the scientific and technological environment based on the dynamic componential model of creativity and innovation and the Triadic Reciprocal Determinism Theory. The study investigates the mediating effect of achievement motivation and the moderating effect of the organizational innovative climate between the meaning of work and innovative behavior. Meaning of work has a positive impact on innovative behavior based on the structural equation modeling and the results of data collected from the survey of 4,666 scientific and technological workers in China. In addition, achievement motivation plays a partial intermediary role between the meaning of work and innovative behavior. However, innovation within organizational climate plays a negative regulatory role between achievement motivation and innovative behavior. The study finds some existing weaknesses through the Importance-Performance Map Analysis. Lastly, we examine the critical findings and present hypothetical suggestions.

15.
Anal Chem ; 94(30): 10850-10856, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35857436

RESUMEN

Technetium (99Tc) is a highly toxic radioactive nuclear wastewater contaminant. Real-time detection of 99Tc is very difficult due to its difficult-to-complex nature. Herein, a novel three-dimensional ionic olefin-linked conjugated microporous polymer (TFPM-EP-Br) is constructed using tetrakis(4-aldehyde phenyl)methane (TFPM) as the central monomer. The unique cationic cavity and highly hydrophobic framework enable TFPM-EP-Br to act as a fluorescent sensor for TcO4-. The fluorophores of TFPM-EP-Br can be quenched due to electron transfer from TFPM-EP-Br to TcO4- and the formation of strongly nonfluorescent complexes. Meanwhile, the regular pore channels are beneficial for the fast mass transfer of TcO4-, resulting in an ultrafast response time (less than 2 s) with an ultralow detection limit (33.3 nM). In addition, the ultrahigh specific surface area enables TFPM-EP-Br to combine the ability to synergistically detect and remove radioactive 99Tc. From this perspective, the novel conjugated microporous polymer has made a breakthrough in the detection and extraction of radioactive contaminants.


Asunto(s)
Polímeros , Aguas Residuales , Alquenos , Cationes , Tecnecio/química
16.
Neural Netw ; 145: 300-307, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34785445

RESUMEN

Clipping on learning rates in Adam leads to an effective stochastic algorithm-AdaBound. In spite of its effectiveness in practice, convergence analysis of AdaBound has not been fully explored, especially for non-convex optimization. To this end, we address the convergence of the last individual output of AdaBound for non-convex stochastic optimization problems, which is called individual convergence. We prove that, with the iteration of the AdaBound, the cost function converges to a finite value and the corresponding gradient converges to zero. The novelty of this proof is that the convergence conditions on the bound functions and momentum factors are much more relaxed than the existing results, especially when we remove the monotonicity and convergence of the bound functions, and only keep their boundedness. The momentum factors can be fixed to be constant, without the restriction of monotonically decreasing. This provides a new perspective on understanding the bound functions and momentum factors of AdaBound. At last, numerical experiments are provided to corroborate our theory and show that the convergence of AdaBound extends to more general bound functions.


Asunto(s)
Algoritmos , Aprendizaje
17.
Neuroscience ; 481: 73-84, 2022 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-34848262

RESUMEN

Presbycusis, or age-related hearing loss (ARHL), is primarily associated with sensory or transduction nerve cell degeneration in the peripheral and/or central auditory systems. During aging, the auditory system shows mitochondrial dysfunction and increased inflammatory responses. Mitochondrial dysfunction promotes leakage of mitochondrial DNA (mtDNA) into the cytosol, which activates the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway to induce type I interferon and inflammatory responses. However, whether this pathway is involved in the occurrence and development of ARHL is unknown. This study aimed to determine whether there are age-related changes in the levels of cytosolic mtDNA and cGAS-STING pathway activation in the auditory pathway and to explore their relationship with ARHL. The results showed that cGAS-positive immunoreactive cells were observed in the cochlea, inferior colliculus, and auditory cortex. Levels of cytosolic mtDNA, cGAS, STING, phosphorylated interferon regulatory factor 3, and cytokines were significantly increased in the cochlea, inferior colliculus, and auditory cortex of 6-, 9-, and 12-month-old mice compared with 3-month-old mice. These findings suggested that cytosolic mtDNA may play an important role in the pathogenesis of ARHL by activating cGAS-STING-mediated type I interferon and inflammatory responses.


Asunto(s)
Interferones , Presbiacusia , Animales , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Nucleótidos Cíclicos , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/metabolismo
18.
Fish Shellfish Immunol ; 98: 414-419, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31962148

RESUMEN

Anti-lipopolysaccharide factors (ALFs), as main host-defense molecules of crustaceans, form a unique family of antimicrobial peptides (AMPs). MnALF4 is one isoform of ALFs isolated from the freshwater prawn Macrobrachium nipponense. In the present study, MnALF4 gene was successfully expressed in the yeast Pichia pastoris and the recombinant MnALF4 protein exhibited efficient and broad-spectrum antimicrobial activities against both Gram-positive bacteria and Gram-negative bacteria in vitro. When prawns were injected with rMnALF4 before bacterial challenge with E. coli, the recombinant protein effectively promote the elimination of bacteria by the host. It manifested that rMnALF4 could effectively kill the invading bacteria in vivo. Treatment with rMnALF4 led to remarkable changes in bacterial morphology, such as spheroidization, oversized bacteria, and cell lysis. In addition, rMnALF4 showed weak hemolysis activity to the rabbit red blood cells. Our work suggests that MnALF4 plays an important role in Macrobrachium immunity and is worthy of further investigation as a potential antibacterial agent with high efficacy against bacterial infection and low toxicity to host cells.


Asunto(s)
Proteínas de Artrópodos/metabolismo , Lipopolisacáridos/inmunología , Palaemonidae/metabolismo , Pichia/metabolismo , Proteínas Recombinantes/metabolismo , Animales , Antiinfecciosos/metabolismo , Antiinfecciosos/farmacología , Proteínas de Artrópodos/química , Proteínas de Artrópodos/genética , Bacterias/efectos de los fármacos , Eritrocitos/efectos de los fármacos , Regulación de la Expresión Génica , Hemólisis/efectos de los fármacos , Pichia/genética , Conejos , Proteínas Recombinantes/genética
19.
Neuroscience ; 398: 12-22, 2019 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-30513374

RESUMEN

Stroke is a leading cause of mortality and serious disability worldwide with limited treatment options. Angiogenesis has been reported to be involved in post-stroke recovery. Although the molecular mechanisms that regulate angiogenesis remain ambiguous, microRNAs have emerged as effective regulators of angiogenesis, involved in neurological function outcome. The present study aims to investigate the regulatory effects of miRNA-27b on post-stroke angiogenesis. In primary cultured brain microvascular endothelial cells (BMECs), the inhibition of miRNA-27b induced the activation of adenosine monophosphate-activated protein kinase (AMPK), which increased tube formation and migration. This action was attenuated when AMPKα2 was knocked down. Mice were subjected to middle cerebral artery occlusion (MCAo) surgery and administrated with Lentivirus miR-27b inhibitor. Enhanced angiogenesis in ischemic boundary zone (IBZ) was observed, and the neurological outcome during the entire study period was improved. The number of phosphate-AMPKα2+ cells that co-expressed endothelial cell marker CD31 was significantly increased. Taken together, the present study demonstrated that downregulated miRNA-27b promoted recovery after ischemic stroke via AMPK stimulus.


Asunto(s)
Isquemia Encefálica/metabolismo , MicroARNs/metabolismo , Neovascularización Fisiológica/fisiología , Accidente Cerebrovascular/metabolismo , Adenilato Quinasa/genética , Adenilato Quinasa/metabolismo , Animales , Encéfalo/irrigación sanguínea , Encéfalo/metabolismo , Encéfalo/patología , Isquemia Encefálica/patología , Células Cultivadas , Modelos Animales de Enfermedad , Regulación hacia Abajo , Células Endoteliales/metabolismo , Células Endoteliales/patología , Masculino , Ratones Endogámicos C57BL , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Accidente Cerebrovascular/patología
20.
J Agric Food Chem ; 66(50): 13141-13151, 2018 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-30463403

RESUMEN

Bacillus subtilis is widely used for large-scale industrial production of heterologous proteins. Because of its high intrinsic secretory capacity, it can efficiently secrete proteins into the culture supernatant via the general Sec-type secretion pathway. In this study, the α-amylase AmyS was used as a reporter to construct a library encompassing 173 Sec-type signal peptides (SPs) from B. subtilis using a fast, sequence-independent method. The resulting library DNA which harbored different signal peptides in the expression vector was used to transform B. subtilis directly at high efficiency, and 15 SPs which produced a significantly increased yield of AmyS were identified using a starch-iodine-based high-throughput assay. Furthermore, the correlation between the sequences of the best-performing signal peptides and their secretion efficiency was analyzed, which revealed several common properties of these SPs. Finally, high-cell-density fermentation of the α-amylase-producing strain with the best-performing signal peptide yielded a maximum of 5086 U/mL amylase at 66 h with a high productivity of 77.1 U/mL·h.


Asunto(s)
Bacillus subtilis/metabolismo , Señales de Clasificación de Proteína , Proteínas Recombinantes/metabolismo , alfa-Amilasas/metabolismo , Bacillus subtilis/genética , Genes Reporteros , Ingeniería de Proteínas , Proteínas Recombinantes/genética , alfa-Amilasas/genética
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