Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 138
Filtrar
1.
Nature ; 613(7943): 365-374, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36544019

RESUMO

How paternal exposure to ionizing radiation affects genetic inheritance and disease risk in the offspring has been a long-standing question in radiation biology. In humans, nearly 80% of transmitted mutations arise in the paternal germline1, but the transgenerational effects of ionizing radiation exposure has remained controversial and the mechanisms are unknown. Here we show that in sex-separated Caenorhabditis elegans strains, paternal, but not maternal, exposure to ionizing radiation leads to transgenerational embryonic lethality. The offspring of irradiated males displayed various genome instability phenotypes, including DNA fragmentation, chromosomal rearrangement and aneuploidy. Paternal DNA double strand breaks were repaired by maternally provided error-prone polymerase theta-mediated end joining. Mechanistically, we show that depletion of an orthologue of human histone H1.0, HIS-24, or the heterochromatin protein HPL-1, could significantly reverse the transgenerational embryonic lethality. Removal of HIS-24 or HPL-1 reduced histone 3 lysine 9 dimethylation and enabled error-free homologous recombination repair in the germline of the F1 generation from ionizing radiation-treated P0 males, consequently improving the viability of the F2 generation. This work establishes the mechanistic underpinnings of the heritable consequences of paternal radiation exposure on the health of offspring, which may lead to congenital disorders and cancer in humans.


Assuntos
Caenorhabditis elegans , Dano ao DNA , Reparo do DNA , Histonas , Animais , Humanos , Masculino , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/efeitos da radiação , Dano ao DNA/efeitos da radiação , Instabilidade Genômica/efeitos da radiação , Histonas/metabolismo , Mutação , Radiação Ionizante , Perda do Embrião/genética , Feminino , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Reparo do DNA por Junção de Extremidades , DNA Polimerase teta
2.
Nano Lett ; 24(9): 2894-2903, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38407042

RESUMO

Harnessing the potential of tumor-associated macrophages (TAMs) to engulf tumor cells offers promising avenues for cancer therapy. Targeting phagocytosis checkpoints, particularly the CD47-signal regulatory protein α (SIRPα) axis, is crucial for modulating TAM activity. However, single checkpoint inhibition has shown a limited efficacy. In this study, we demonstrate that ferrimagnetic vortex-domain iron oxide (FVIO) nanoring-mediated magnetic hyperthermia effectively suppresses the expression of CD47 protein on Hepa1-6 tumor cells and SIRPα receptor on macrophages, which disrupts CD47-SIRPα interaction. FVIO-mediated magnetic hyperthermia also induces immunogenic cell death and polarizes TAMs toward M1 phenotype. These changes collectively bolster the phagocytic ability of macrophages to eliminate tumor cells. Furthermore, FVIO-mediated magnetic hyperthermia concurrently escalates cytotoxic T lymphocyte levels and diminishes regulatory T cell levels. Our findings reveal that magnetic hyperthermia offers a novel approach for dual down-regulation of CD47 and SIRPα, reshaping the tumor microenvironment to stimulate immune responses, culminating in significant antitumor activity.


Assuntos
Hipertermia Induzida , Neoplasias , Humanos , Antígeno CD47 , Regulação para Baixo , Imunoterapia , Fagocitose , Fenômenos Magnéticos , Neoplasias/patologia , Microambiente Tumoral
3.
J Am Chem Soc ; 146(31): 21903-21912, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39046794

RESUMO

In photoelectrochemical (PEC) cells, selective oxidation of organic substrates coupled with hydrogen evolution represents a promising approach for value-added chemical production and solar energy conversion. In this study, we report on PEC epoxidation of alkenes at a ruthenium dye-sensitized photoanode in a CH3CN/H2O mixed solvent with LiBr as a mediator and water as the oxygen source. The dye-sensitized photoanode was found to exhibit significant advantages in the simultaneous improvement of charge separation and suppression of charge recombination. First, LiBr as a redox mediator plays a critical role in charge separation, leading to an excellent excited electron injection efficiency of 95% and a high dye regeneration efficiency of 87%. Second, the predominant charge recombination pathway on the dye-sensitized photoanode is efficiently blocked by the reaction between alkene and the in situ generated bromine oxidant. As a result, the current system achieved a remarkable photocurrent density of over 4 mA cm-2 with a record-high incident photo-to-current efficiency (IPCE) of 51% and extraordinary selectivity of up to 99% for the epoxidation of a wide range of alkenes. Meanwhile, nearly 100% Faradaic efficiency for hydrogen evolution was obtained. The performance shown here exceeds that obtained by metal oxide-based semiconductor photoanodes under comparable conditions, demonstrating the great potential of dye-sensitized photoelectrodes for organic synthesis owing to their diversity and tunability.

4.
Development ; 148(19)2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34495314

RESUMO

Zebrafish provide an excellent model for in vivo cell biology studies because of their amenability to live imaging. Protein visualization in zebrafish has traditionally relied on overexpression of fluorescently tagged proteins from heterologous promoters, making it difficult to recapitulate endogenous expression patterns and protein function. One way to circumvent this problem is to tag the proteins by modifying their endogenous genomic loci. Such an approach is not widely available to zebrafish researchers because of inefficient homologous recombination and the error-prone nature of targeted integration in zebrafish. Here, we report a simple approach for tagging proteins in zebrafish on their N or C termini with fluorescent proteins by inserting PCR-generated donor amplicons into non-coding regions of the corresponding genes. Using this approach, we generated endogenously tagged alleles for several genes that are crucial for epithelial biology and organ development, including the tight junction components ZO-1 and Cldn15la, the trafficking effector Rab11a, the apical polarity protein aPKC and the ECM receptor Integrin ß1b. Our approach facilitates the generation of knock-in lines in zebrafish, opening the way for accurate quantitative imaging studies.


Assuntos
Técnicas de Introdução de Genes/métodos , Proteínas de Fluorescência Verde/genética , Proteínas de Peixe-Zebra/genética , Animais , Proteínas de Fluorescência Verde/metabolismo , Mutagênese Insercional , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sequências Reguladoras de Ácido Nucleico/genética , Peixe-Zebra , Proteínas de Peixe-Zebra/metabolismo
5.
Plant Biotechnol J ; 22(8): 2157-2172, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38506090

RESUMO

Chilling stress has seriously limited the global production and geographical distribution of rice. However, the molecular mechanisms associated with plant responses to chilling stress are less known. In this study, we revealed a member of ß-ketoacyl-ACP synthase I family (KASI), OsKASI-2 which confers chilling tolerance in rice. OsKASI-2 encodes a chloroplast-localized KASI enzyme mainly expressed in the leaves and anthers of rice and strongly induced by chilling stress. Disruption of OsKASI-2 led to decreased KAS enzymatic activity and the levels of unsaturated fatty acids, which impairs degree of unsaturation of membrane lipids, thus increased sensitivity to chilling stress in rice. However, the overexpression of OsKASI-2 significantly improved the chilling tolerance ability in rice. In addition, OsKASI-2 may regulate ROS metabolism in response to chilling stress. Natural variation of OsKASI-2 might result in difference in chilling tolerance between indica and japonica accessions, and Hap1 of OsKASI-2 confers chilling tolerance in rice. Taken together, we suggest OsKASI-2 is critical for regulating degree of unsaturation of membrane lipids and ROS accumulation for maintenance of membrane structural homeostasis under chilling stress, and provide a potential target gene for improving chilling tolerance of rice.


Assuntos
Temperatura Baixa , Regulação da Expressão Gênica de Plantas , Lipídeos de Membrana , Oryza , Proteínas de Plantas , Oryza/genética , Oryza/metabolismo , Oryza/fisiologia , Lipídeos de Membrana/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Estresse Fisiológico , Espécies Reativas de Oxigênio/metabolismo
6.
Ophthalmic Physiol Opt ; 44(2): 472-480, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38234008

RESUMO

PURPOSE: With the rising prevalence of myopia, especially among the young, orthokeratology (Ortho-K) stands out as a promising approach, not only to reduce myopia but also to control the progression of axial length (AL). This study examined how the intersection area between the pupil and defocus ring influenced retinal defocus and axial growth after Ortho-K. METHODS: A case-control study was conducted with 100 participants (100 eyes). Both AL and the refraction difference value (RDV), that is, the peripheral refractive error measured with respect to the central value after wearing Ortho-K lenses, were determined. Subjects were categorised into two groups based on the size of the intersection area after 3 months of lens wear: Group A (<4.58 mm2 ) and Group B (≥4.58 mm2 ). RESULTS: Group B demonstrated significantly lower changes in AL and RDV at 30-40° and 40-53° compared with Group A after 3 months of lens wear (all p < 0.05). After 6 months of lens wear, Group B showed significantly lower changes in AL and RDV in the 40-53° region compared with Group A (all p < 0.05). Correlation analysis revealed that as the intersection area increased, the changes in AL and RDV at 0-53°, 30-40° and 40-53° eccentricity decreased after both 3 and 6 months of lens wear (all p < 0.01). CONCLUSIONS: A larger intersection area between the pupil and defocus ring within a certain time period can cause a greater amount of myopic defocus at 30-53° from the fovea. The results suggest that a larger intersection area might lead to more effective control of axial growth.


Assuntos
Miopia , Procedimentos Ortoceratológicos , Erros de Refração , Humanos , Pupila , Estudos de Casos e Controles , Retina , Refração Ocular , Comprimento Axial do Olho , Procedimentos Ortoceratológicos/métodos
7.
Postgrad Med J ; 100(1181): 151-158, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38134327

RESUMO

PURPOSE: To evaluate the effectiveness and safety of electroacupuncture (EA) using intermittent wave stimulation in enhancing facial symmetry and nerve function in chronic Bell's palsy patients. METHODS: A 6-week assessor-blinded, randomized trial followed by an 18-week observational period was conducted. Sixty individuals with chronic Bell's palsy, showing no signs of recovery after 12 months, were equally divided to receive either 18 sessions of EA using intermittent wave stimulation or Transcutaneous Electrical Stimulation (TES), administered thrice weekly over 6 weeks. The primary outcome measure was the change in the total facial nerve index (TFNI) score from baseline to Week 6, with secondary outcomes including TFNI scores at Weeks 12 and 24, as well as the change in Sunnybrook Facial Grading System (SFG) score from baseline to Week 6, and SFG scores at Weeks 12 and 24. RESULTS: The EA group showed a significant improvement, with a mean total facial nerve index score increase of 24.35 (4.77) by Week 6 compared with 14.21 (5.12) in the Transcutaneous Electrical Stimulation group (P<.001). This superiority persisted during the 24-week follow-up. While no significant difference was observed in the Sunnybrook Facial Grading System score change from baseline to Week 6, variations were noted at Weeks 12 and 24. No major adverse effects were reported. CONCLUSION: EA with intermittent wave stimulation notably enhanced facial symmetry in chronic Bell's palsy patients over Transcutaneous Electrical Stimulation by Week 6, maintaining this edge throughout the follow-up.


Assuntos
Paralisia de Bell , Eletroacupuntura , Humanos , Paralisia de Bell/terapia , Paralisia de Bell/diagnóstico , Nervo Facial , Projetos de Pesquisa , Face
8.
J Environ Manage ; 354: 120211, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38340664

RESUMO

Peroxydisulfate (PDS) and peroxymonosulfate (PMS) could be efficiently activated by heat to generate reactive oxygen species (ROS) for the degradation of organic contaminants. However, defects including the inefficiency treatment and pH dependence of monooxidant process are prominent. In this study, synergy of heat and the PDS-PMS binary oxidant was studied for efficient triclosan (TCS) degradation and apply in rubber wastewater. Under different pH values, the degradation of TCS followed pseudo-first-order kinetics, the reaction rate constant (kobs) value of TCS in heat/PDS/PMS system increased from 1.8 to 4.4 fold and 6.8-49.1 fold when compared to heat/PDS system and heat/PMS system, respectively. Hydroxyl radicals (·OH), sulfate radicals (SO4·-) and singlet oxygen (1O2) were the major ROS for the degradation of TCS in heat/PDS/PMS system. In addition, the steady-state concentrations of ·OH/1O2 and SO4·-/·OH/1O2 increased under acidic conditions and alkaline conditions, respectively. It was concluded that the pH regulated the ROS for degradation of TCS in heat/PDS/PMS system significantly. Based on the analysis of degradation byproducts, it was inferred that the dechlorination, hydroxylation and ether bond breaking reactions occurred during the degradation of TCS. Moreover, the biological toxicity of the ten byproducts was lower than that of TCS was determined. Furthermore, the heat/PDS/PMS system is resistant to the influence of water substrates and can effectively improve the water quality of rubber wastewater. This study provides a novel perspective for efficient degradation of TCS independent of pH in the heat/PDS/PMS system and its application of rubber wastewater.


Assuntos
Triclosan , Poluentes Químicos da Água , Oxidantes/química , Águas Residuárias , Espécies Reativas de Oxigênio , Borracha , Oxirredução , Poluentes Químicos da Água/química , Peróxidos/química
9.
J Antimicrob Chemother ; 78(5): 1288-1294, 2023 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-36995982

RESUMO

BACKGROUND: We found a carbapenem-resistant Escherichia coli without known carbapenemase-encoding genes and performed a study to identify the possible new carbapenemase. METHODS: The production of carbapenemase was examined using the modified carbapenem inactivation method. The strain was subjected to short- and long-read genome sequencing and the complete genome was obtained by hybrid assembly. The gene encoding a potential new OXA-type carbapenemase was cloned. The enzyme was purified and was then subjected to kinetic assays. Molecular docking analysis of the enzyme was performed using the MOE software suite. Mating experiments were attempted to obtain the plasmid carrying the corresponding gene. RESULTS: We identified and characterized a novel class D carbapenem-hydrolysing ß-lactamase, OXA-1041, in a carbapenem-resistant E. coli clinical strain. OXA-1041 had 89.77% (237/264) amino acid identity with OXA-427, a known carbapenemase. By cloning in an E. coli laboratory strain, blaOXA-1041 was found to reduce susceptibility to ertapenem by 16 times (MIC 0.25 versus 0.016 mg/L) and meropenem by four times (MIC 0.06 versus 0.016 mg/L) but did not significantly reduce susceptibility to imipenem and doripenem. Enzyme kinetic measurement of purified OXA-1041 showed that OXA-1041 could hydrolyse ertapenem and meropenem with a turnover number (kcat)/Michaelis constant (KM) of 8.57 and 3.63 mM-1s-1, respectively. The complete genome contained a single plasmid (223 341 bp, IncF, containing five replicons), which was self-transmissible. blaOXA-1041 was downstream of insertion sequence ISCR1 and there were three tandem copies of ISCR1-blaOXA-1041-creDΔ (encoding an envelope protein) on this plasmid. CONCLUSIONS: The above findings suggest OXA-1041 is a new plasmid-encoded carbapenemase with preferential activity against ertapenem.


Assuntos
Carbapenêmicos , Escherichia coli , Carbapenêmicos/farmacologia , Carbapenêmicos/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Meropeném , Ertapenem/farmacologia , Simulação de Acoplamento Molecular , beta-Lactamases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Testes de Sensibilidade Microbiana
10.
Plant Cell Environ ; 46(4): 1402-1418, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36510797

RESUMO

Chilling stress has become a major limiting factor that reduces crop productivity worldwide. In this study, we identified a new gene bHLH57, whose product enhances chilling tolerance in rice at diverse developmental stages. bHLH57 was mainly expressed in leaves and anthers, and its protein was targeted to the nucleus. Overexpression of bHLH57 enhanced chilling tolerance by increasing trehalose synthesis, whereas its mutants by CRISPR/Cas9-mediated mutagenesis were more sensitive to chilling and had reduced trehalose. Meanwhile, bHLH57 may regulate ROS metabolism and CBFs/DREBs- dependent pathways in response to chilling stress. In addition, the overexpression of bHLH57 resulted in increased grain yield under normal and chilling conditions, however, the disruption of bHLH57 displayed decreased grain size and seed setting rate, thus reduced grain yield. Phylogenetic and nucleotide diversity analyses suggested that bHLH57 is relatively conserved in monocotyledons, and may be selected during indica populations adaptation. Taken together, we have identified a new bHLH regulator involved rice chilling tolerance and grain yield, and provide a potential target gene for improving chilling tolerance and grain yield of rice.


Assuntos
Oryza , Oryza/fisiologia , Trealose/metabolismo , Filogenia , Grão Comestível/metabolismo , Sementes/fisiologia , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
11.
Plant Cell Environ ; 46(4): 1384-1401, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36319615

RESUMO

Preharvest sprouting (PHS) is an unfavorable trait in cereal crops and causes serious yield loss. However, the molecular mechanism underlying PHS remains largely elusive. Here, we identified a member of 9-cis-epoxycarotenoid dioxygenase family, OsNCED3, which regulates PHS and grain development in rice (Oryza sativa L.). OsNCED3 encodes a chloroplast-localized abscisic acid (ABA) biosynthetic enzyme highly expressed in the embryo of developing seeds. Disruption of OsNCED3 by CRISPR/Cas9-mediated mutagenesis led to a lower ABA and higher gibberellic acid (GA) levels (thus a skewed ABA/GA ratio) in the embryo, promoting embryos growth and breaking seed dormancy before seed maturity and harvest, thus decreased seed dormancy and enhanced PHS in rice. However, the overexpression of OsNCED3 enhanced PHS resistance by regulating proper ABA/GA ratio in the embryo. Intriguingly, the overexpression of OsNCED3 resulted in increased grain size and weight, whereas the disruption of OsNCED3 function decreased grain size and weight. Nucleotide diversity analyses suggested that OsNCED3 may be selected during japonica populations adaptation of seed dormancy and germination. Taken together, we have identified a new OsNCED regulator involved rice PHS and grain development, and provide a potential target gene for improving PHS resistance and grain development in rice.


Assuntos
Grão Comestível , Oryza , Grão Comestível/fisiologia , Oryza/fisiologia , Germinação/genética , Dormência de Plantas/genética , Ácido Abscísico , Sementes/fisiologia , Regulação da Expressão Gênica de Plantas
12.
Langmuir ; 39(16): 5679-5688, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37040602

RESUMO

Emerging pollutants, such as sulfonamide antibiotics and pharmaceuticals, have been widely detected in water and soils, posing serious environmental and human health concerns. Thus, it is urgent and necessary to develop a technology for removing them. In this work, a hydrothermal carbonization method was used to prepare the hydrochars (HCs) by pine sawdust with different temperatures. To improve the physicochemical properties of HCs, phosphoric acid (H3PO4) and hydrogen peroxide (H2O2) were used to modify these HCs, and they were referred to as PHCs and HHCs, respectively. The adsorption of sulfamethoxazole (SMX) and carbamazepine (CBZ) by pristine and modified HCs was investigated systematically. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicated that the H2O2/H3PO4 modification led to the formation of a disordered carbon structure and abundant pores. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy results suggested that carboxyl (-COOH) and hydroxyl (-OH) functional groups of HCs increased after modification, which is the main reason for the higher sorption of SMX and CBZ on H3PO4/H2O2-modified HCs when compared with pristine HCs. In addition, the positive correlation between -COOH/C=O and logKd of these two chemicals also suggested that oxygen-containing functional groups played a crucial role in the sorption of SMX and CBZ. The strong hydrophobic interaction and π-π interaction between CBZ and pristine/modified HCs resulted in its higher adsorption when compared with SMX. The results of this study provide a novel perspective on the investigation of adsorption mechanisms and environmental behaviors for organic contaminants by pristine and modified HCs.


Assuntos
Sulfametoxazol , Poluentes Químicos da Água , Humanos , Sulfametoxazol/química , Peróxido de Hidrogênio , Carvão Vegetal/química , Oxigênio , Adsorção , Carbamazepina/análise , Carbamazepina/química , Poluentes Químicos da Água/análise , Cinética
13.
Dig Dis ; 41(3): 396-404, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36455540

RESUMO

BACKGROUND: The prevalence of inflammatory bowel disease (IBD) is rapidly increasing in China. Beyond disease management, frailty is an important predictor of adverse outcomes in IBD patients, which has not been well investigated. This study aimed to assess frailty status and explore the impact factors in IBD inpatients. METHODS: A total of 372 IBD inpatients were recruited from July 2021 to November 2021 at Peking Union Medical College Hospital. All the participants were surveyed by face-to-face questionnaires, including demographic characteristics, disease conditions, lifestyle, psychology, social support, and frailty. The impact factors of frailty were further assessed by multinomial logistic regression analysis. RESULTS: The participants' median age was 31.00 (Q1: 24.00, Q3: 40.00) years. The overall prevalence of prefrailty and frailty in IBD patients was 59.4% (n = 221) and 14% (n = 52), respectively, and was higher for frailty in females (17.2%) than in males (12.3%). Increased body mass index (odds ratio (OR) 0.917; 95% confidence interval (CI) 0.860-0.978), increased erythrocyte sedimentation rate (OR 1.039; 95% CI: 1.002-1.077), sleep impairment (OR 5.160; 95% CI: 2.394-11.119), and depression (OR 9.480; 95% CI: 3.602-24.949) were independently significantly correlated with prefrailty (p < 0.05). Increased body mass index (OR 0.744; 95% CI: 0.654-0.848), increased erythrocyte sedimentation rate (OR 1.052; 95% CI: 1.011-1.096), sleep impairment (OR 5.832; 95% CI: 2.092-16.260), and depression (OR 10.041; 95% CI: 2.740-36.793) were independently significantly correlated with frailty. Among the factors, whether for frailty or prefrailty, the strongest impact factor was depression. CONCLUSIONS: IBD inpatients are prone to frailty. Comprehensive management focused on the prevention of frailty is warranted to improve the overall prognosis.


Assuntos
Colite Ulcerativa , Fragilidade , Doenças Inflamatórias Intestinais , Masculino , Feminino , Humanos , Adulto , Prevalência , Centros de Atenção Terciária , Fragilidade/epidemiologia , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/epidemiologia , China/epidemiologia , Fatores de Risco
14.
Sensors (Basel) ; 23(5)2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36904637

RESUMO

Recent advances in training monitoring are centered on the statistical indicators of the concentric phase of the movement. However, those studies lack consideration of the integrity of the movement. Moreover, training performance evaluation needs valid data on the movement. Thus, this study presents a full-waveform resistance training monitoring system (FRTMS) as a whole-movement-process monitoring solution to acquire and analyze the full-waveform data of resistance training. The FRTMS includes a portable data acquisition device and a data processing and visualization software platform. The data acquisition device monitors the barbell's movement data. The software platform guides users through the acquisition of training parameters and provides feedback on the training result variables. To validate the FRTMS, we compared the simultaneous measurements of 30-90% 1RM of Smith squat lifts performed by 21 subjects with the FRTMS to similar measurements obtained with a previously validated three-dimensional motion capture system. Results showed that the FRTMS produced practically identical velocity outcomes, with a high Pearson's correlation coefficient, intraclass correlation coefficient, and coefficient of multiple correlations and a low root mean square error. We also studied the applications of the FRTMS in practical training by comparing the training results of a six-week experimental intervention with velocity-based training (VBT) and percentage-based training (PBT). The current findings suggest that the proposed monitoring system can provide reliable data for refining future training monitoring and analysis.


Assuntos
Treinamento Resistido , Humanos , Treinamento Resistido/métodos , Postura , Software , Transdutores , Monitorização Fisiológica , Arritmias Cardíacas , Força Muscular
15.
High Educ (Dordr) ; 85(5): 1101-1123, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35702421

RESUMO

COVID-19 has caused the overnight migration of learning and teaching to online platforms and has significantly impacted students' learning opportunities and experiences worldwide. The results of emergency online learning have heavily relied on students' abilities to exercise agency in maintaining active motivation and engagement with online learning. Despite the wide application of motivation theories to diverse contexts, how to adapt motivation theories to develop online learning effectively and sustainably in complex and situational online learning environments is still under-investigated. Using a large sample of 14,935 postgraduate students from 31 universities in China, this study examined the effects of student motivation and engagement on students' academic achievement in the COVID-induced online learning anchored by the theoretical perspective of self-determination theory. This study made contribution to the self-determination theory by extending it to the complex emergency situation and supported its main argument that online emergency learning environments satisfying students' psychological needs of autonomy and competence promote optimal motivation, positive engagement and academic achievement. This study also contributed to reveal the 'sophisticated' nature of relatedness satisfaction in the case wherein its specific effects depend on the cultural configuration of the contexts and on the specific types of engagement. Given the fact that COVID-19 continues to be a public challenge throughout the world, implications for improving the quality of online teaching in the future were also discussed.

16.
J Am Chem Soc ; 144(3): 1232-1242, 2022 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-35034454

RESUMO

Native chemical ligation (NCL) provides a powerful solution to assemble proteins with precise chemical features, which enables a detailed investigation of the protein structure-function relationship. As an extension to NCL, the discovery of desulfurization and expressed protein ligation (EPL) techniques has greatly expanded the efficient access to large or challenging protein sequences via chemical ligations. Despite its superior reliability, the NCL-desulfurization protocol requires orthogonal protection strategies to allow selective desulfurization in the presence of native Cys, which is crucial to its synthetic application. In contrast to traditional thiol protecting groups, photolabile protecting groups (PPGs), which are removed upon irradiation, simplify protein assembly and therefore provide minimal perturbation to the peptide scaffold. However, current PPG strategies are mainly limited to nitro-benzyl derivatives, which are incompatible with NCL-desulfurization. Herein, we present for the first time that quinoline-based PPG for cysteine can facilitate various ligation strategies, including iterative NCL and EPL-desulfurization methods. 7-(Piperazin-1-yl)-2-(methyl)quinolinyl (PPZQ) caging of multiple cysteine residues within the protein sequence can be readily introduced via late-stage modification, while the traceless removal of PPZQ is highly efficient via photolysis in an aqueous buffer. In addition, the PPZQ group is compatible with radical desulfurization. The efficiency of this strategy has been highlighted by the synthesis of γ-synuclein and phosphorylated cystatin-S via one-pot iterative ligation and EPL-desulfurization methods. Besides, successful sextuple protection and deprotection of the expressed Interleukin-34 fragment demonstrate the great potential of this strategy in protein caging/uncaging investigations.


Assuntos
Proteínas
17.
Anal Chem ; 94(41): 14099-14108, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36197877

RESUMO

Extracellular vesicle (EV) cargos with regular fluctuations hold the potential for providing chemical predictors toward clinical diagnosis and prognosis. A plasma sample is one of the most important sources of circulating EVs, yet the technical barrier and cost consumption in plasma-EV isolation still limit its application in disease diagnosis and biomarker discovery. Here, we introduced an easy-to-use strategy that allows selectively purifying small EVs (sEVs) from human plasma and detecting their metabolic alternations. Fe3O4@TiO2 microbeads with a rough island-shaped surface have proven the capability of performing efficient and reversible sEV capture owing to the phospholipid affinity, enhanced binding sites, and size-exclusion-like effect of the rough TiO2 shell. The proposed system can also shorten the separation procedure from hours to 20 min when compared with the ultracentrifugation method and yield approximately 108 sEV particles from 100 µL of plasma. Metabolome variations of sEVs among progressive diabetic retinopathy subjects were finally studied, observing a cluster of metabolites with elevated levels and suggesting potential roles of these sEV chemicals in diabetic retinopathy onset and progression. Such a scalable and flexible EV capture system can be seen as an effective analytical tool for facilitating plasma-based liquid biopsies.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Vesículas Extracelulares , Biomarcadores/análise , Diabetes Mellitus/metabolismo , Retinopatia Diabética/diagnóstico , Retinopatia Diabética/metabolismo , Vesículas Extracelulares/química , Humanos , Fosfolipídeos/análise , Titânio
18.
Small ; 18(34): e2202956, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35908166

RESUMO

The disulfide compounds of molybdenum (MoS2 ) are layered van der Waals materials that exhibit a rich array of polymorphic structures. MoS2 can be roughly divided into semiconductive phase and metallic phase according to the difference in electron filling state of the 4d orbital of Mo atom. The two phases show completely different properties, leading to their diverse applications in biosensors. But to some extent, they compensate for each other. This review first introduces the relationship between phase state and the chemical/physical structures and properties of MoS2 . Furthermore, the synthetic methods are summarized and the preparation strategies for metastable phases are highlighted. In addition, examples of electronic and chemical property designs of MoS2 by means of doping and surface modification are outlined. Finally, studies on biosensors based on MoS2 in recent years are presented and classified, and the roles of MoS2 with different phases are highlighted. This review offers references for the selection of materials to construct different types of biosensors based on MoS2 , and provides inspiration for sensing performance enhancement.


Assuntos
Técnicas Biossensoriais , Molibdênio , Técnicas Biossensoriais/métodos , Dissulfetos/química , Molibdênio/química
19.
J Nanobiotechnology ; 20(1): 547, 2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36587223

RESUMO

Cancer immunotherapy has shown promising therapeutic results in the clinic, albeit only in a limited number of cancer types, and its efficacy remains less than satisfactory. Nanoparticle-based approaches have been shown to increase the response to immunotherapies to address this limitation. In particular, magnetic nanoparticles (MNPs) as a powerful manipulator are an appealing option for comprehensively regulating the immune system in vivo due to their unique magnetically responsive properties and high biocompatibility. This review focuses on assessing the potential applications of MNPs in enhancing tumor accumulation of immunotherapeutic agents and immunogenicity, improving immune cell infiltration, and creating an immunotherapy-sensitive environment. We summarize recent progress in the application of MNP-based manipulators to augment the efficacy of immunotherapy, by MNPs and their multiple magnetically responsive effects under different types of external magnetic field. Furthermore, we highlight the mechanisms underlying the promotion of antitumor immunity, including magnetically actuated delivery and controlled release of immunotherapeutic agents, tracking and visualization of immune response in real time, and magnetic regulation of innate/adaptive immune cells. Finally, we consider perspectives and challenges in MNP-based immunotherapy.


Assuntos
Nanopartículas , Neoplasias , Humanos , Imunoterapia , Neoplasias/tratamento farmacológico , Magnetismo , Campos Magnéticos , Nanopartículas/uso terapêutico
20.
Molecules ; 27(14)2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35889395

RESUMO

A low molecular weight fucosylated glycosaminoglycan sodium (LFG-Na) is a novel anticoagulant candidate from the sea cucumber Holothuria fuscopunctata that selectively inhibits intrinsic tenase (iXase). The molecular weight, molecular weight distribution and bioactivities are the critical quality attributes of LFG-Na. The determination of these quality attributes of such an oligosaccharides mixture drug is challenging but critical for the quality control process to ensure its safety and efficacy in clinical use. Herein, the molecular weight and molecular weight distribution of LFG-Na were successfully determined using high performance size exclusion chromatography coupled with multi angle laser light scattering and refractive index detector (HPSEC-MALLS-RID). Comparing to the conventional method, HPSEC-MALLS-RID based on the refractive index increment (dn/dc) did not require the reference substances to establish the calibration curve. The acceptance criteria of LFG-Na were established, the weight-average molecular weight (Mw) should be 4000 to 6000 Da, the polydispersity (Mw/Mn) < 1.40, and the fraction with molecular weights of 1500 to 8000 Da should be no less than 80% of the total. HPSEC-MALLS-RID was also utilized for the determination of the starting material native fucosylated glycosaminoglycan (NFG) to choose a better manufacturing process. Furthermore, APTT assay was selected and the potency of anti-iXase, referring to the parallel line assay (PLA) method, was established to clarify the consistency of its biological activities. The results suggest that HPSEC-MALLS-RID and bioactivity assays are critical quality control methods for multi-component glycosaminoglycan LFG-Na. The methods also provide a feasible strategy to control the quality of other polysaccharide medicines.


Assuntos
Anticoagulantes , Glicosaminoglicanos , Animais , Anticoagulantes/química , Anticoagulantes/farmacologia , Cromatografia em Gel , Glicosaminoglicanos/farmacologia , Peso Molecular , Controle de Qualidade , Sódio
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA