Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 378
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 121(18): e2401060121, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38648475

RESUMO

Electrochromic (EC) displays with electronically regulating the transmittance of solar radiation offer the opportunity to increase the energy efficiency of the building and electronic products and improve the comfort and lifestyle of people. Despite the unique merit and vast application potential of EC technologies, long-awaited EC windows and related visual content displays have not been fully commercialized due to unsatisfactory production cost, durability, color, and complex fabrication processes. Here we develop a unique EC strategy and system based on the natural host and guest interactions to address the above issues. A completely reusable and sustainable EC device has been fabricated with potential advantages of extremely low cost, ideal user-/environment friendly property, and excellent optical modulation, which is benefited from the extracted biomass EC materials and reusable transparent electrodes involved in the system. The as-prepared EC window and nonemissive transparent display also show comprehensively excellent properties: high transmittance change (>85%), broad spectra modulation covering Ultraviolet (UV), Visible (Vis) to Infrared (IR) ranges, high durability (no attenuation under UV radiation for more than 1.5 mo), low open voltage (0.9 V), excellent reusability (>1,200 cycles) of the device's key components and reversibility (>4,000 cycles) with a large transmittance change, and pleasant multicolor. It is anticipated that unconventional exploration and design principles of dynamic host-guest interactions can provide unique insight into different energy-saving and sustainable optoelectronic applications.

2.
Anticancer Drugs ; 35(4): 371-376, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38241197

RESUMO

To investigate the effects of tamoxifen (TAM) and toremifene (TOR) on hepatic function and serum lipid levels in breast cancer patients receiving adjuvant endocrine therapy. The clinical data of 597 early breast cancer patients treated at the First Affiliated Hospital of Nanjing Medical University between January 2016 and December 2022 were collected. All the patients received standard adjuvant endocrine therapy with TAM or TOR after chemotherapy. Hepatic function and serum lipid data of all patients before and at 6 months and 1, 2, and 3 years after the treatment were collected retrospectively and analyzed statistically. There: no negative effect on hepatic function was observed in patients treated with either TAM or TOR. The triglyceride levels in both groups increased during treatment, and the effect of TAM on improving total cholesterol levels was stronger. Total cholesterol levels were not affected by time or treatment regimen. The low-density lipoprotein cholesterol levels decreased in both groups, and the effect was similar between groups. TAM can decrease the high-density lipoprotein cholesterol levels, whereas TOR can increase the high-density lipoprotein cholesterol levels, and there was a significant difference between groups. In the postoperative adjuvant endocrine therapy, TOR and TAM will not negatively impact the hepatic function of breast cancer patients, and TOR is better than TAM in the management of serum lipids; therefore, it may be a better choice for clinical medication.


Assuntos
Neoplasias da Mama , Toremifeno , Humanos , Feminino , Toremifeno/uso terapêutico , Toremifeno/farmacologia , Tamoxifeno/farmacologia , Estudos Retrospectivos , Antineoplásicos Hormonais/efeitos adversos , Quimioterapia Adjuvante , Adjuvantes Imunológicos , Lipídeos/uso terapêutico , Colesterol , Lipoproteínas HDL/uso terapêutico
3.
Chem Rev ; 122(18): 14679-14721, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-35980039

RESUMO

With the rapid development of optoelectronic fields, electrochromic (EC) materials and devices have received remarkable attention and have shown attractive potential for use in emerging wearable and portable electronics, electronic papers/billboards, see-through displays, and other new-generation displays, due to the advantages of low power consumption, easy viewing, flexibility, stretchability, etc. Despite continuous progress in related fields, determining how to make electrochromics truly meet the requirements of mature displays (e.g., ideal overall performance) has been a long-term problem. Therefore, the commercialization of relevant high-quality products is still in its infancy. In this review, we will focus on the progress in emerging EC materials and devices for potential displays, including two mainstream EC display prototypes (segmented displays and pixel displays) and their commercial applications. Among these topics, the related materials/devices, EC performance, construction approaches, and processing techniques are comprehensively disscussed and reviewed. We also outline the current barriers with possible solutions and discuss the future of this field.


Assuntos
Dispositivos Eletrônicos Vestíveis , Eletrônica
4.
Proc Natl Acad Sci U S A ; 118(6)2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33526657

RESUMO

RNA polymerase II (Pol II) generally pauses at certain positions along gene bodies, thereby interrupting the transcription elongation process, which is often coupled with various important biological functions, such as precursor mRNA splicing and gene expression regulation. Characterizing the transcriptional elongation dynamics can thus help us understand many essential biological processes in eukaryotic cells. However, experimentally measuring Pol II elongation rates is generally time and resource consuming. We developed PEPMAN (polymerase II elongation pausing modeling through attention-based deep neural network), a deep learning-based model that accurately predicts Pol II pausing sites based on the native elongating transcript sequencing (NET-seq) data. Through fully taking advantage of the attention mechanism, PEPMAN is able to decipher important sequence features underlying Pol II pausing. More importantly, we demonstrated that the analyses of the PEPMAN-predicted results around various types of alternative splicing sites can provide useful clues into understanding the cotranscriptional splicing events. In addition, associating the PEPMAN prediction results with different epigenetic features can help reveal important factors related to the transcription elongation process. All these results demonstrated that PEPMAN can provide a useful and effective tool for modeling transcription elongation and understanding the related biological factors from available high-throughput sequencing data.


Assuntos
Genoma Humano , Aprendizado de Máquina , Modelos Biológicos , Elongação da Transcrição Genética , Sequência de Bases , Sítios de Ligação , Metilação de DNA/genética , Epigênese Genética , Células HEK293 , Células HeLa , Histonas/metabolismo , Humanos , Motivos de Nucleotídeos/genética , Processamento de Proteína Pós-Traducional , RNA Polimerase II/metabolismo , Sítios de Splice de RNA/genética , Splicing de RNA/genética
5.
Int J Mol Sci ; 25(13)2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-39000588

RESUMO

Sand pear is the main cultivated pear species in China, and brown peel is a unique feature of sand pear. The formation of brown peel is related to the activity of the cork layer, of which lignin is an important component. The formation of brown peel is intimately associated with the biosynthesis and accumulation of lignin; however, the regulatory mechanism of lignin biosynthesis in pear peel remains unclear. In this study, we used a newly bred sand pear cultivar 'Xinyu' as the material to investigate the biosynthesis and accumulation of lignin at nine developmental stages using metabolomic and transcriptomic methods. Our results showed that the 30 days after flowering (DAF) to 50DAF were the key periods of lignin accumulation according to data analysis from the assays of lignin measurement, scanning electron microscope (SEM) observation, metabolomics, and transcriptomics. Through weighted gene co-expression network analysis (WGCNA), positively correlated modules with lignin were identified. A total of nine difference lignin components were identified and 148 differentially expressed genes (DEGs), including 10 structural genes (PAL1, C4H, two 4CL genes, HCT, CSE, two COMT genes, and two CCR genes) and MYB, NAC, ERF, and TCP transcription factor genes were involved in lignin metabolism. An analysis of RT-qPCR confirmed that these DEGs were involved in the biosynthesis and regulation of lignin. These findings further help us understand the mechanisms of lignin biosynthesis and provide a theoretical basis for peel color control and quality improvement in pear breeding and cultivation.


Assuntos
Frutas , Regulação da Expressão Gênica de Plantas , Lignina , Metaboloma , Pyrus , Transcriptoma , Lignina/biossíntese , Lignina/metabolismo , Pyrus/genética , Pyrus/metabolismo , Pyrus/crescimento & desenvolvimento , Frutas/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimento , Redes e Vias Metabólicas , Perfilação da Expressão Gênica/métodos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
Int J Environ Health Res ; 34(2): 1156-1167, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37158781

RESUMO

A retrospective analysis of birth data hospital-based obtained from 14 monitoring areas in the Huaihe River Basin from 2009 to 2019 was conducted. Trend in the total prevalence of birth defects (BDs) and subgroups were analyzed using the Joinpoint Regression model. The incidence of BDs increased gradually from 118.87 per 10,000 in 2009 to 241.18 per 10,000 in 2019 (AAPC = 5.91, P < 0.001). Congenital heart diseases were the most common subtype of BDs. The proportion of maternal age younger than 25 decreased but the age 25-40 years increased significantly (AAPC<20=-5.58; AAPC20-24=-6.38; AAPC25-29 = 5.15; AAPC30-35 = 7.07; AAPC35-40 = 8.27; All P < 0.05). Compared with the one-child policy period, the risk of BDs was greater for groups among maternal age younger than 40 years during the partial and universal two-child policy period (P < 0.001). The incidence of BDs and the proportion of women with advanced maternal age in Huaihe River Basin is increasing. There was an interaction between changes in birth policy and the mother's age on the risk of BDs.


Assuntos
Políticas , Humanos , Feminino , Adulto , Estudos Transversais , Estudos Retrospectivos , Idade Materna , China/epidemiologia
7.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(1): 31-36, 2024 Jan 15.
Artigo em Zh | MEDLINE | ID: mdl-38269456

RESUMO

OBJECTIVES: To study the efficacy of bronchoalveolar lavage (BAL) combined with prone positioning in children with Mycoplasma pneumoniae pneumonia (MPP) and atelectasis and its effect on pulmonary function. METHODS: A prospective study was conducted on 94 children with MPP and atelectasis who were hospitalized in Ordos Central Hospital of Inner Mongolia from November 2020 to May 2023. The children were randomly divided into a treatment group and a control group, with 47 children in each group. The children in the treatment group were given conventional treatment, BAL, and prone positioning, and those in the control group were given conventional treatment and BAL. The two groups were compared in terms of fever, pulmonary signs, length of hospital stay, lung recruitment, and improvement in pulmonary function. RESULTS: Compared with the control group, the treatment group had significantly shorter time to improvement in pulmonary signs and length of hospital stay and a significantly higher rate of lung recruitment on day 7 of hospitalization, on the day of discharge, and at 1 week after discharge (P<0.05). Compared with the control group, the treatment group had significantly higher levels of forced vital capacity (FVC) as a percentage of the predicted value, forced expiratory volume (FEV) in 1 second as a percentage of the predicted value, ratio of FEV in 1 second to FVC, forced expiratory flow at 50% of FVC as a percentage of the predicted value, forced expiratory flow at 75% of FVC as a percentage of the predicted value, and maximal mid-expiratory flow as a percentage of the predicted value on the day of discharge and at 1 week after discharge (P<0.05). There was no significant difference in the time for body temperature to return to normal between the two groups (P>0.05). CONCLUSIONS: In the treatment of children with MPP and atelectasis, BAL combined with prone positioning can help to shorten the time to improvement in pulmonary signs and the length of hospital stay and promote lung recruitment and improvement in pulmonary function.


Assuntos
Pneumonia por Mycoplasma , Atelectasia Pulmonar , Criança , Humanos , Estudos Prospectivos , Mycoplasma pneumoniae , Decúbito Ventral , Atelectasia Pulmonar/terapia , Pneumonia por Mycoplasma/terapia , Lavagem Broncoalveolar , Dimercaprol
8.
Anal Chem ; 95(9): 4344-4352, 2023 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-36815760

RESUMO

Analysis of volatile organic compounds (VOCs) in exhaled breath (EB) has shown great potential for disease detection including lung cancer, infectious respiratory diseases, and chronic obstructive pulmonary disease. Although many breath sample collection and analytical methods have been developed for breath analysis, analysis of metabolic VOCs in exhaled breath is still a challenge for clinical application. Many carbonyl compounds in exhaled breath are related to the metabolic processes of diseases. This work reports a method of ultrahigh-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-MS) for the analysis of a broad range of carbonyl metabolites in exhaled breath. Carbonyl compounds in the exhaled breath were captured by a fabricated silicon microreactor with a micropillar array coated with 2-(aminooxy)ethyl-N,N,N-trimethylammonium (ATM) triflate. A total of six subgroups consisting of saturated aldehydes and ketones, hydroxy-aldehydes, and hydroxy-ketones, unsaturated 2-alkenals, and 4-hydroxy-2-alkenals were identified in the exhaled breath. The combination of a silicon microreactor for the selective capture of carbonyl compounds with UHPLC-MS analysis may provide a quantitative method for the analysis of carbonyls to identify disease markers in exhaled breath.


Assuntos
Silício , Compostos Orgânicos Voláteis , Cromatografia Líquida de Alta Pressão , Compostos Orgânicos Voláteis/análise , Aldeídos/análise , Cetonas/análise , Testes Respiratórios/métodos
9.
Brief Bioinform ; 22(5)2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-33479731

RESUMO

Translation elongation is a crucial phase during protein biosynthesis. In this study, we develop a novel deep reinforcement learning-based framework, named Riboexp, to model the determinants of the uneven distribution of ribosomes on mRNA transcripts during translation elongation. In particular, our model employs a policy network to perform a context-dependent feature selection in the setting of ribosome density prediction. Our extensive tests demonstrated that Riboexp can significantly outperform the state-of-the-art methods in predicting ribosome density by up to 5.9% in terms of per-gene Pearson correlation coefficient on the datasets from three species. In addition, Riboexp can indicate more informative sequence features for the prediction task than other commonly used attribution methods in deep learning. In-depth analyses also revealed the meaningful biological insights generated by the Riboexp framework. Moreover, the application of Riboexp in codon optimization resulted in an increase of protein production by around 31% over the previous state-of-the-art method that models ribosome density. These results have established Riboexp as a powerful and useful computational tool in the studies of translation dynamics and protein synthesis. Availability: The data and code of this study are available on GitHub: https://github.com/Liuxg16/Riboexp. Contact:zengjy321@tsinghua.edu.cn; songsen@tsinghua.edu.cn.


Assuntos
Códon/metabolismo , Biologia Computacional , Modelos Biológicos , Biossíntese de Proteínas , Ribossomos/metabolismo
10.
Cell Biol Toxicol ; 39(6): 3077-3100, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37495868

RESUMO

Hyperhomocysteinemia (HHcy) plays a salient role in male infertility. However, whether HHcy interferes with testosterone production remains inconclusive. Here, we reported a lower serum testosterone level in HHcy mice. Single-cell RNA sequencing revealed that genes related to testosterone biosynthesis, together with nuclear receptor subfamily 5 group A member 1 (Nr5a1), a key transcription factor for steroidogenic genes, were downregulated in the Leydig cells (LCs) of HHcy mice. Mechanistically, Hcy lowered trimethylation of histone H3 on lysine 4 (H3K4me3), which was bound on the promoter region of Nr5a1, resulting in downregulation of Nr5a1. Intriguingly, we identified an unknown cell cluster annotated as Macrophage-like Leydig cells (McLCs), expressing both LCs and macrophages markers. In HHcy mice, McLCs were shifted toward pro-inflammatory phenotype and thus promoted inflammatory response in LC. Betaine supplementation rescued the downregulation of NR5A1 and restored the serum testosterone level in HHcy mice. Overall, our study highlights an etiological role of HHcy in LCs dysfunction.


Assuntos
Hiper-Homocisteinemia , Células Intersticiais do Testículo , Camundongos , Masculino , Animais , Células Intersticiais do Testículo/metabolismo , Testosterona , Hiper-Homocisteinemia/metabolismo , Macrófagos/metabolismo , Fatores de Transcrição/genética
11.
J Comput Assist Tomogr ; 47(6): 959-966, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37948372

RESUMO

OBJECTIVE: This study aimed to perform an assessment of brain microstructure in children with autism aged 2 to 5 years using relaxation times acquired by synthetic magnetic resonance imaging. MATERIALS AND METHODS: Thirty-four children with autism spectrum disorder (ASD) (ASD group) and 17 children with global developmental delay (GDD) (GDD group) were enrolled, and synthetic magnetic resonance imaging was performed to obtain T1 and T2 relaxation times. The differences in brain relaxation times between the 2 groups of children were compared, and the correlation between significantly changed T1/T2 and clinical neuropsychological scores in the ASD group was analyzed. RESULTS: Compared with the GDD group, shortened T1 relaxation times in the ASD group were distributed in the genu of corpus callosum (GCC) ( P = 0.003), splenium of corpus callosum ( P = 0.002), and right thalamus (TH) ( P = 0.014), whereas shortened T2 relaxation times in the ASD group were distributed in GCC ( P = 0.011), left parietal white matter ( P = 0.035), and bilateral TH (right, P = 0.014; left, P = 0.016). In the ASD group, the T2 of the left parietal white matter is positively correlated with gross motor (developmental quotient [DQ] 2) and personal-social behavior (DQ5), respectively ( r = 0.377, P = 0.028; r = 0.392, P = 0.022); the T2 of the GCC was positively correlated with DQ5 ( r = 0.404, P = 0.018); and the T2 of the left TH is positively correlated with DQ2 and DQ5, respectively ( r = 0.433, P = 0.009; r = 0.377, P = 0.028). All significantly changed relaxation values were not significantly correlated with Childhood Autism Rating Scale scores. CONCLUSIONS: The shortened relaxometry times in the brain of children with ASD may be associated with the increased myelin content and decreased water content in the brain of children with ASD in comparison with GDD, contributing the understanding of the pathophysiology of ASD. Therefore, the T1 and T2 relaxometry may be used as promising imaging markers for ASD diagnosis.


Assuntos
Transtorno do Espectro Autista , Encefalopatias , Substância Branca , Humanos , Pré-Escolar , Criança , Transtorno do Espectro Autista/diagnóstico por imagem , Transtorno do Espectro Autista/patologia , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Corpo Caloso/diagnóstico por imagem , Corpo Caloso/patologia
12.
Mar Drugs ; 21(5)2023 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-37233493

RESUMO

Numerous compounds present in the ocean are contributing to the development of the biomedical field. Agarose, a polysaccharide derived from marine red algae, plays a vital role in biomedical applications because of its reversible temperature-sensitive gelling behavior, excellent mechanical properties, and high biological activity. Natural agarose hydrogel has a single structural composition that prevents it from adapting to complex biological environments. Therefore, agarose can be developed into different forms through physical, biological, and chemical modifications, enabling it to perform optimally in different environments. Agarose biomaterials are being increasingly used for isolation, purification, drug delivery, and tissue engineering, but most are still far from clinical approval. This review classifies and discusses the preparation, modification, and biomedical applications of agarose, focusing on its applications in isolation and purification, wound dressings, drug delivery, tissue engineering, and 3D printing. In addition, it attempts to address the opportunities and challenges associated with the future development of agarose-based biomaterials in the biomedical field. It should help to rationalize the selection of the most suitable functionalized agarose hydrogels for specific applications in the biomedical industry.


Assuntos
Materiais Biocompatíveis , Hidrogéis , Sefarose/química , Hidrogéis/química , Materiais Biocompatíveis/química , Engenharia Tecidual , Sistemas de Liberação de Medicamentos
13.
Angew Chem Int Ed Engl ; 62(22): e202302365, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-36973174

RESUMO

Synthesis of highly stable two-dimensional single-layer assemblies (SLAs) is a key challenge in supramolecular science, especially those with long-range molecular order and well-defined morphology. Here, thin (thickness <2 nm) triangular AuI -thiolate SLAs with high thermo-, solvato- and mechano- stability have been synthesized via a double-ligand co-assembly strategy. Furthermore, the SLAs show assembly-level elastic and anisotropic deformation responses to external stimuli as a result of the long-range anisotropic molecular packing, which provides SLAs with new application potentials in bio-mimic nanomechanics.

14.
Acc Chem Res ; 54(9): 2216-2226, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33881840

RESUMO

ConspectusStimuli-responsive materials have a great potential in various novel photoelectric devices, such as self-adaptive adjustment devices, intelligent detection, molecular computers with information storage capability, camouflage and anticounterfeiting display, various energy-saving displays, and others. However, progress in related areas has been relatively slow because of the lack of high-performance smart materials and the limitations of available reaction mechanisms currently. To address these problems fundamentally, new mechanisms need to be designed and developed, and learning from nature is an effective and intelligent method to achieve this long-awaited target, such as mimicking of proton transfer processes in nature at the molecular/supramolecular level. The stimuli-induced reversible proton transfer system is composed of materials that release or capture protons in response to stimuli and switch molecules that control color and/or fluorescence modulation by protons, and it is applied in stimuli-responsive materials and devices, including bistable electronic/electrochromic devices, electrofluorochromic devices, water-jet rewritable paper, visible-light-responsive rewritable paper, and mechanochromic materials.To help researchers gain deep insight into stimuli-induced reversible proton transfer, we attempted to summarize its reaction mechanism and design principle, and discuss strategies to design and prepare various related stimuli-responsive materials and devices. This Account discusses the different systems in which a color/fluorescence change is induced by the proton transfer process under various stimuli, including electric field, water, light, heat, and stress. Relative very promising applications as well as their performance especially for energy-saving and environmentally friendly devices are then summarized, such as energy-saving bistable electrochromic devices, water-jet rewritable paper, and visible-light-responsive rewritable paper. Meanwhile, we focus on the key influence factors and useful additives for improving the device's performance. At last, challenges and bottlenecks faced by stimuli-responsive materials and devices based on the mechanism of reversible proton transfer are proposed. Moreover, we put forward some suggestions on solving these limitations.These exciting results reveal that smart materials based on the mechanism of proton transfer are extremely attractive and possess great potential in the next generation of energy and resource saving and environmental protection display. We hope that this Account further prospers the field of intelligent stimuli-responsive discoloration materials and next-generation green displays.

15.
Mar Drugs ; 20(2)2022 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-35200655

RESUMO

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.


Assuntos
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/metabolismo
16.
Mar Drugs ; 20(12)2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36547930

RESUMO

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.


Assuntos
Tolerância ao Sal , Cloreto de Sódio , Carragenina/química , Bactérias/metabolismo , Glicosídeo Hidrolases/metabolismo , Proteínas de Bactérias/metabolismo
17.
BMC Plant Biol ; 21(1): 426, 2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34537013

RESUMO

BACKGROUND: Reproduction in most flowering plants may be limited because of the decreased visitation or activity of pollinators in fragmented habitats. Hedysarum scoparium Fisch. et Mey. is an arid region shrub with ecological importance. We explored the pollen limitation and seed set of Hedysarum scoparium in fragmented and restored environments, and examined whether pollen limitation is a significant limiting factor for seed set. We also compared floral traits and pollinator visitation between both habitats, and we determined the difference of floral traits and pollinators influenced reproductive success in Hedysarum scoparium. RESULTS: Our results indicated that supplementation with pollen significantly increased seed set per flower, which is pollen-limited in this species. Furthermore, there was greater seed set of the hand cross-pollination group in the restored habitat compared to the fragmented environment. More visits by Apis mellifera were recorded in the restored habitats, which may explain the difference in seed production between the fragmented and restored habitats. CONCLUSIONS: In this study, a positive association between pollinator visitation frequency and open flower number was observed. The findings of this study are important for experimentally quantifying the effects of floral traits and pollinators on plant reproductive success in different habitats.


Assuntos
Fabaceae/fisiologia , Flores/fisiologia , Pólen/fisiologia , Animais , China , Ecossistema , Polinização , Sementes/crescimento & desenvolvimento
18.
J Neuroinflammation ; 18(1): 133, 2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34118948

RESUMO

BACKGROUND: Brain ischemia compromises natural killer (NK) cell-mediated immune defenses by acting on neurogenic and intracellular pathways. Less is known about the posttranscriptional mechanisms that regulate NK cell activation and cytotoxicity after ischemic stroke. METHODS: Using a NanoString nCounter® miRNA array panel, we explored the microRNA (miRNA) profile of splenic NK cells in mice subjected to middle cerebral artery occlusion. Differential gene expression and function/pathway analysis were applied to investigate the main functions of predicted miRNA target genes. miR-1224 inhibitor/mimics transfection and passive transfer of NK cells were performed to confirm the impact of miR-1224 in NK cells after brain ischemia. RESULTS: We observed striking dysregulation of several miRNAs in response to ischemia. Among those miRNAs, miR-1224 markedly increased 3 days after ischemic stroke. Transfection of miR-1224 mimics into NK cells resulted in suppression of NK cell activity, while an miR-1224 inhibitor enhanced NK cell activity and cytotoxicity, especially in the periphery. Passive transfer of NK cells treated with an miR-1224 inhibitor prevented the accumulation of a bacterial burden in the lungs after ischemic stroke, suggesting an enhanced immune defense of NK cells. The transcription factor Sp1, which controls cytokine/chemokine release by NK cells at the transcriptional level, is a predicted target of miR-1224. The inhibitory effect of miR-1224 on NK cell activity was blocked in Sp1 knockout mice. CONCLUSIONS: These findings indicate that miR-1224 may serve as a negative regulator of NK cell activation in an Sp1-dependent manner; this mechanism may be a novel target to prevent poststroke infection specifically in the periphery and preserve immune defense in the brain.


Assuntos
Encéfalo/metabolismo , AVC Isquêmico/metabolismo , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/patologia , MicroRNAs/metabolismo , Transdução de Sinais , Fator de Transcrição Sp1/metabolismo , Animais , Encéfalo/diagnóstico por imagem , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Infarto da Artéria Cerebral Média/metabolismo , AVC Isquêmico/diagnóstico por imagem , Células Matadoras Naturais/imunologia , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL
19.
BMC Pregnancy Childbirth ; 21(1): 353, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33947356

RESUMO

BACKGROUND: Pelvic girdle pain (PGP) is a multifactorial condition with a partly unknown etiology. This condition can be mentally and physically compromising both during and after pregnancy. To provide all-around preventive measures to improve the recovery from PGP, it is a necessity for obstetricians and orthopaedists to develop predictive studies about the worse prognosis for this condition. Therefore, this study aims to determine whether personality traits can predict the consequences of long-term pregnancy-related PGP. METHODS: This was a prospective study conducted from January 2015 to August 2018. A total of 387 pregnant women were enrolled in this study. According to whether they had experienced PGP during the past 4 weeks, the subjects were classified into no PGP and PGP groups. Persistent PGP after the pregnancy was defined as a recurrent or continuous visual analog score (VAS) pain rating of ≥3 for more than 1 week. The Quick Big Five Personality Test (QBFPT) was used to assess personality traits. Data were obtained by mail or in the clinic. The authors collected data including age, BMI, educational level, annual household income, cesarean delivery, breastfeeding, unexpected sex of the baby, parity, sick leave, no or rare ability to take rest breaks at work, and PGP in the previous pregnancy. RESULTS: Of 387 included women, 264 subjects experienced PGP during the pregnancy with a mean age of 26.3 ± 4.5 years. A total of 80 of 264 (30.3%) women experienced persistent PGP after the pregnancy. Persistent PGP after the pregnancy was associated with higher levels of neuroticism (OR = 2.12, P = 0.001). Comparing women with persistent PGP, those who reported higher levels of extraversion and conscientiousness were more likely to recover from this condition (OR = 0.65, P = 0.001; OR = 0.78, P = 0.010, respectively). Besides, neuroticism was positively associated with higher pain scores (r = 0.52, P = 0.005). However, extraversion and conscientiousness domains showed negative correlations with pain score (r = - 0.48, P = 0.003; r = - 0.36, P = 0.001). CONCLUSIONS: Personality traits were significantly associated with the outcomes of PGP.


Assuntos
Dor da Cintura Pélvica/psicologia , Personalidade , Complicações na Gravidez/psicologia , Adulto , Feminino , Humanos , Medição da Dor , Testes de Personalidade , Período Pós-Parto , Gravidez , Estudos Prospectivos , Fatores de Risco
20.
Acta Biochim Biophys Sin (Shanghai) ; 53(1): 10-18, 2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33210711

RESUMO

Cell migration and invasion are two essential processes during cancer metastasis. Increasing evidence has shown that the Piezo1 channel is involved in mediating cell migration and invasion in some types of cancers. However, the role of Piezo1 in the breast cancer and its underlying mechanisms have not been clarified yet. Here, we show that Piezo1 is high-expressed in breast cancer cell (BCC) lines, despite its complex expression in clinical patient database. Piezo1 knockdown (Piezo1-KD) promotes unconfined BCC migration, but impedes confined cell migration. Piezo1 may mediate BCC migration through the balances of cell adhesion, cell stiffness, and contractility. Furthermore, Piezo1-KD inhibits BCC invasion by impairing the invadopodium formation and suppressing the expression of metalloproteinases (MMPs) as well. However, the proliferation and cell cycle of BCCs are not significantly affected by Piezo1. Our study highlights a crucial role of Piezo1 in regulating migration and invasion of BCCs, indicating Piezo1 channel might be a new prognostic and therapeutic target in BCCs.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Movimento Celular , Canais Iônicos/genética , Canais Iônicos/metabolismo , Actinas/metabolismo , Fenômenos Biomecânicos , Neoplasias da Mama/imunologia , Linhagem Celular Tumoral , Movimento Celular/genética , Bases de Dados Genéticas , Feminino , Adesões Focais/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Metaloproteinases da Matriz/metabolismo , Invasividade Neoplásica/genética , Podossomos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA