Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Org Biomol Chem ; 22(19): 3871-3875, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38651649

RESUMO

A cost-effective, practical, straightforward and scalable synthesis of α-pyrones via base- and sulfur-promoted annulation of phenylacetates and chalcones is reported. Generated in situ from the starting components by using dbu as a base catalyst, the Michael adducts underwent a smooth oxidative cyclization into 3,4,6-triaryl-2-pyranones upon heating with DABCO and sulfur in DMSO. Extension to malonate in place of phenylacetates led to 4,6-diaryl-2-pyranone-2-carboxylates.

2.
BMC Oral Health ; 24(1): 230, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38350906

RESUMO

BACKGROUND: The present study aimed to evaluate the effectiveness of using platelet-rich fibrin (PRF) as the apical matrix for the placement of MTA in nonsurgical endodontic therapy for teeth with periapical lesions and open apices. METHODS: Twelve teeth from eleven patients with periapical periodontitis and open apices were enrolled in the study. Nonsurgical endodontic therapy was performed with the PRF used as an apical barrier and the MTA manipulated as an apical plug for further thermoplasticized gutta percha in the remaining part of the root canal. Clinical signs and periapical digital radiographs were recorded and analyzed to evaluate the curing progress after periodical follow-ups of 1, 3, and 6 months. The horizontal dimension of the periapical lesion was determined, and the changes in the dimensions were recorded each time. The Friedman test was used for statistical analysis, with P < .05 serving as the threshold for determining statistical significance. RESULTS: All patients had no clinical symptoms after the first month of treatment, with a significant reduction in the periapical lesion after periodical appointments. CONCLUSIONS: PRF is an effective barrier when combined with MTA for the treatment of teeth with periapical periodontitis and open apices.


Assuntos
Periodontite Periapical , Fibrina Rica em Plaquetas , Materiais Restauradores do Canal Radicular , Humanos , Compostos de Cálcio/uso terapêutico , Materiais Restauradores do Canal Radicular/uso terapêutico , Guta-Percha/uso terapêutico , Periodontite Periapical/terapia , Periodontite Periapical/patologia , Combinação de Medicamentos , Ápice Dentário/diagnóstico por imagem , Ápice Dentário/patologia , Óxidos/uso terapêutico , Silicatos/uso terapêutico
3.
BMC Cancer ; 23(1): 233, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36915069

RESUMO

BACKGROUND: Late detection of hepatocellular carcinoma (HCC) results in an overall 5-year survival rate of less than 16%. Liquid biopsy (LB) assays based on detecting circulating tumor DNA (ctDNA) might provide an opportunity to detect HCC early noninvasively. Increasing evidence indicates that ctDNA detection using mutation-based assays is significantly challenged by the abundance of white blood cell-derived mutations, non-tumor tissue-derived somatic mutations in plasma, and the mutational tumor heterogeneity. METHODS: Here, we employed concurrent analysis of cancer-related mutations, and their fragment length profiles to differentiate mutations from different sources. To distinguish persons with HCC (PwHCC) from healthy participants, we built a classification model using three fragmentomic features of ctDNA through deep sequencing of thirteen genes associated with HCC. RESULTS: Our model achieved an area under the curve (AUC) of 0.88, a sensitivity of 89%, and a specificity of 82% in the discovery cohort consisting of 55 PwHCC and 55 healthy participants. In an independent validation cohort of 54 PwHCC and 53 healthy participants, the established model achieved comparable classification performance with an AUC of 0.86 and yielded a sensitivity and specificity of 81%. CONCLUSIONS: Our study provides a rationale for subsequent clinical evaluation of our assay performance in a large-scale prospective study.


Assuntos
Carcinoma Hepatocelular , DNA Tumoral Circulante , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Estudos Prospectivos , Biomarcadores Tumorais/genética , Mutação
4.
Aging Male ; 26(1): 2223712, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37335039

RESUMO

PURPOSE: Hypogonadism is associated with a wide range of physical and psychological symptoms that can affect the overall health of men. However, in a developing country, there are several imposing challenges in the diagnosis and treatment of hypogonadism, including a lack of awareness and understanding of the condition among healthcare providers and patients, limited resources and the high cost of treatment. This review aimed to examine the potential benefits and risks of testosterone replacement therapy (TRT) and provides a perspective of a developing country on the topic. MATERIALS AND METHODS: A comprehensive literature review was conducted to gather relevant information on the impact of testosterone deficiency on ageing males and the effectiveness of TRT for treating hypogonadism. Published peer-reviewed articles were analyzed to evaluate the benefits and risks of TRT. Additionally, the unique challenges faced in the diagnosis and treatment of hypogonadism in a developing country were considered. RESULTS: Testosterone replacement therapy has been shown to be an effective treatment for hypogonadism, particularly in symptomatic men with low testosterone levels. It offers potential benefits such as improvements in symptoms and overall quality of life. However, there are associated risks and side effects that need to be considered. In a developing country, challenges such as limited awareness and understanding of hypogonadism, resource constraints, and high treatment costs pose additional barriers to accessing TRT and comprehensive care. CONCLUSION: In conclusion, TRT holds promise as a treatment for hypogonadism, but its implementation and accessibility face significant challenges in a developing country. Addressing these challenges, including raising awareness, allocating resources, and finding cost-effective solutions, is crucial for ensuring that men with hypogonadism in such settings receive appropriate diagnosis and treatment. Further research and efforts are needed to improve the management of hypogonadism in developing countries and optimize the potential benefits of TRT for affected individuals.


Assuntos
Hipogonadismo , Testosterona , Humanos , Masculino , Qualidade de Vida , Países em Desenvolvimento , Hipogonadismo/diagnóstico , Hipogonadismo/tratamento farmacológico , Hipogonadismo/etiologia , Envelhecimento , Terapia de Reposição Hormonal
5.
J Asian Nat Prod Res ; : 1-11, 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37889019

RESUMO

Alkaloids are among the most important and best-known secondary metabolites as sources of new drugs from medicinal plants and marine organisms. A phytochemical investigation of the whole plant of Crinum asiaticum var. sinicum resulted in the isolation of seven alkaloids (1-7), including one new dimeric compound, bis-(-)-8-demethylmaritidine (1). Their structures were elucidated using NMR and HR-ESI-MS. The absolute configuration of new compound 1 was established by circular dichroism spectroscopy. All isolated compounds were evaluated for their inhibitory effects on acetylcholinesterase (AChE) activity in vitro. Among them, compound 1 exhibited the most potent AChE inhibition. Moreover, molecular docking and molecular dynamics simulations were carried out for the most active compound to investigate their binding interactions and dynamics behavior of the AChE protein-ligand complex. Therefore, compound 1 may be a potential candidate for effectively treating Alzheimer's disease.

6.
Cancer Invest ; 40(4): 354-365, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34894952

RESUMO

Identification of tumor-derived mutation (TDM) in liquid biopsies (LB), especially in early-stage patients, faces several challenges, including low variant-allele frequencies, interference by white blood cell (WBC)-derived mutations (WDM), benign somatic mutations and tumor heterogeneity. Here, we addressed the above-mentioned challenges in a cohort of 50 nonmetastatic colorectal cancer patients, via a workflow involving parallel sequencing of paired WBC- and tumor-gDNA. After excluding potential false positive mutations, we detected at least one TDM in LB of 56% (28/50) of patients, with the majority showing low-patient coverage, except for one TDM mapped to KMT2D that recurred in 30% (15/30) of patients.


Assuntos
Ácidos Nucleicos Livres , DNA Tumoral Circulante , Neoplasias Colorretais , Ácidos Nucleicos Livres/genética , DNA Tumoral Circulante/genética , Neoplasias Colorretais/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação
7.
Nanotechnology ; 33(25)2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35287123

RESUMO

With its excellent mechanical and thermal properties, bilayer graphane is a promising material for realizing future nanoelectromechanical systems. In this study, we focus on the auxetic behavior of bilayer graphane under external loading along various directions through atomistic simulations. We numerically and theoretically reveal the mechanism of the auxeticity in terms of intrinsic interactions between carbon atoms by constructing bilayer graphane. Given that the origin of the auxeticity is intrinsic rather than extrinsic, the work provides a novel technique to control the dimensions of nanoscale bilayer graphane by simply changing the external conditions without the requirement of complex structural design of the material.

8.
Andrologia ; 54(2): e14333, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34961956

RESUMO

Testicular size is an important parameter to investigate male reproductive and sexual functions. However, diagnosis and treatments are hindered by the lack of country-specific standard values for testicular volume. We conducted the present retrospective chart review study on 24,440 men who sought consultation at Andrology and Sexual Medicine-Hanoi Medical University Hospital to provide a reference range of testicular volume and to determine the correlations between testicular volume, age and hormonal profiles. These men were classified into groups being healthy fathers, hypogonadal men, unexplained infertile men, men with unknown fertility, testicular pathologies and other andrological condition groups. Hypogonadal men and unexplained infertile men had significantly smaller testicular sizes compared with healthy fathers. The mean value of testicular volume of healthy subjects was 13.64 ± 3.44 ml (left testis: 13.94 ± 3.72 ml; right testis: 13.34 ± 3.61 ml; p < 0.001). Testicular size of Vietnamese men was negatively correlated with LH and FSH (Rho = -0.16 and -0.33, p < 0.001) and positively correlated with testosterone after adjusting for confounding factors. Testicular volume was independent of the subject's age and smoking habits.


Assuntos
Infertilidade Masculina , Ultrassom , Adulto , Povo Asiático , Humanos , Masculino , Estudos Retrospectivos , Testículo , Testosterona
9.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 253-269, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34281323

RESUMO

The diabetes and osteoporotic metabolic diseases are characterized by a wide prevalence of the population worldwide and correlated to alteration of the bone tissues. Several cofactors could influence the clinical course and the biochemistry of the pathologies such as human microbiome, nutrition characteristics, gut microbiota activity and interactions with vitamin K and D across IGF/GH and TP53 signaling pathways and the glucose/energy as mechanism for bone tissue health. Moreover, also the calories and sugar consumption seem to be correlated to an increased inflammatory state with several consequences for hematopoiesis and host tissues response. The aim of the present literature review was to highlight the role of osteoporotic diseases and diabetes type 2 link for the bone metabolism. The literature cases showed that a correlation between bone-gut-kidney-heart-CNS-Immunity crosstalk seems to be linked with bone metabolism and health regulation. Moreover, also the aging process could represent a valuable co-factor for the sustaining of the metabolic disorders upon a multi-systemic level.


Assuntos
Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Doenças Metabólicas , Osso e Ossos , Hematopoese , Humanos
10.
Plant Cell Rep ; 40(5): 819-834, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33725150

RESUMO

KEY MESSAGE: Ectopic expression of Glycine max two-component system member GmHP08 in Arabidopsis enhanced drought tolerance of transgenic plants, possibly via ABA-dependent pathways. Phosphorelay by two-component system (TCS) is a signal transduction mechanism which has been evolutionarily conserved in both prokaryotic and eukaryotic organisms. Previous studies have provided lines of evidence on the involvement of TCS genes in plant perception and responses to environmental stimuli. In this research, drought-associated functions of GmHP08, a TCS member from soybean (Glycine max L.), were investigated via its ectopic expression in Arabidopsis system. Results from the drought survival assay showed that GmHP08-transgenic plants exhibited higher survival rates compared with their wild-type (WT) counterparts, indicating better drought resistance of the former group. Analyses revealed that the transgenic plants outperformed the WT in various regards, i.e. capability of water retention, prevention of hydrogen peroxide accumulation and enhancement of antioxidant enzymatic activities under water-deficit conditions. Additionally, the expression of stress-marker genes, especially antioxidant enzyme-encoding genes, in the transgenic plants were found greater than that of the WT plants. In contrary, the expression of SAG13 gene, one of the senescence-associated genes, and of several abscisic acid (ABA)-related genes was repressed. Data from this study also revealed that the ectopic expression lines at germination and early seedling development stages were hypersensitive to exogenous ABA treatment. Taken together, our results demonstrated that GmHP08 could play an important role in mediating plant response to drought, possibly via an ABA-dependent manner.


Assuntos
Arabidopsis/metabolismo , Ácido Abscísico/farmacologia , Arabidopsis/genética , Secas , Expressão Ectópica do Gene/genética , Expressão Ectópica do Gene/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo
11.
Biophys J ; 118(10): 2400-2410, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32375021

RESUMO

Bacteria tumble periodically, following environmental cues. Whether they can tumble near a solid surface is a basic issue for the inception of infection or mineral biofouling. Observing freely swimming Escherichia coli near and parallel to a glass surface imaged at high magnification (×100) and high temporal resolution (500 Hz), we identified tumbles as events starting (or finishing, respectively) in abrupt deceleration (or reacceleration, respectively) of the body motion. Selected events show an equiprobable clockwise (CW) or counterclockwise change in direction that is superimposed on a surface CW path because of persistent propulsion. These tumbles follow a common long (about 300 ± 100 ms, N = 52) deceleration-reorientation-acceleration pattern. A wavelet transform multiscale analysis shows these tumbles cause in-plane diffusive reorientations with 1.5 rad2/s rotational diffusivity, a value that compares with that measured in bulk tumbles. In half of the cases, additional few-millisecond bursts of an almost equiprobable CW or counterclockwise change of direction (12 ± 90°, N = 89) occur within the reorientation stage. The highly dispersed absolute values of change of direction (70 ± 66°, N = 89) of only a few bursts destabilize the cell-swimming direction. These first observations of surface tumbles set a foundation for statistical models of run-and-tumble surface motion different from that in bulk and lend support for chemotaxis near solid surface.


Assuntos
Escherichia coli , Modelos Biológicos , Fenômenos Biomecânicos , Quimiotaxia , Flagelos , Modelos Estatísticos
12.
Int J Mol Sci ; 21(1)2019 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31906240

RESUMO

Being master regulators of gene expression, transcription factors (TFs) play important roles in determining plant growth, development and reproduction. To date, many TFs have been shown to positively mediate plant responses to environmental stresses. In the current study, the biological functions of a stress-responsive NAC [NAM (No Apical Meristem), ATAF1/2 (Arabidopsis Transcription Activation Factor1/2), CUC2 (Cup-shaped Cotyledon2)]-TF encoding gene isolated from soybean (GmNAC019) in relation to plant drought tolerance and abscisic acid (ABA) responses were investigated. By using a heterologous transgenic system, we revealed that transgenic Arabidopsis plants constitutively expressing the GmNAC019 gene exhibited higher survival rates in a soil-drying assay, which was associated with lower water loss rate in detached leaves, lower cellular hydrogen peroxide content and stronger antioxidant defense under water-stressed conditions. Additionally, the exogenous treatment of transgenic plants with ABA showed their hypersensitivity to this phytohormone, exhibiting lower rates of seed germination and green cotyledons. Taken together, these findings demonstrated that GmNAC019 functions as a positive regulator of ABA-mediated plant response to drought, and thus, it has potential utility for improving plant tolerance through molecular biotechnology.


Assuntos
Ácido Abscísico/metabolismo , Arabidopsis , Resistência à Doença/genética , Glycine max/genética , Plantas Geneticamente Modificadas , Proteínas de Soja , Fatores de Transcrição , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Desidratação/genética , Desidratação/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Proteínas de Soja/biossíntese , Proteínas de Soja/genética , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética
14.
Langmuir ; 33(37): 9254-9261, 2017 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-27996265

RESUMO

Citric acid and its analogues have been investigated as surface-modifying agents for Si nanoparticle anodes using electrochemical cycling, attenuated total reflectance infrared (ATR IR), and X-ray photoelectron spectroscopy (XPS). A Si nanoparticle anode prepared with citric acid (CA) has better capacity retention than one containing 1,2,3,4-butanetetracarboxylic acid (BA), but both electrodes outperform Si-PVDF. The Si-CA anode has an initial specific capacity of 3530 mA h/g and a first cycle efficiency of 82%. Surprisingly, the Si-CA electrode maintains a high specific capacity of ∼2200 mA h/g after 250 cycles, corresponding to 64% capacity retention, which is similar to the Si prepared with long-chain poly(acrylic acid) (PAA). On the contrary, the silicon electrode prepared with PVDF has a fast capacity fade and retains only 980 mA h/g after 50 cycles. The IR and XPS data show that the Si-CA electrode has an SEI composed primarily of lithium citrate during the first 50 cycles, resulting from the electrochemical reduction of citric acid. Only low concentrations of electrolyte reduction products are observed. The lithium citrate layer derived from CA stabilizes the silicon surface and suppresses electrolyte reduction, which likely contributes to the enhanced cycling performance of the Si nanoparticle anode.

15.
Sch Psychol Int ; 38(1): 22-41, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28260822

RESUMO

The purposes of this study were to (a) assess the efficacy of a universal classroom-based mental health and social skills program for primary school students in Vietnam, and (b) given the universal nature of the intervention, assess outcomes as a function of risk status (high vs. low). RECAP-VN is a semi-structured program that provides students with classroom social skills training, and teachers with in-classroom consultation on program implementation and classroom-wide behavior management. Project data were collected at three time-points across the academic year from 443 2nd grade students in regards to their social skills and mental health functioning, in the Vietnamese cities of Hanoi and Danang. Mental health functioning (emotional and behavioral mental health problems) was the ultimate outcome target (at Time 3), with social skills intermediate (at Time 2) outcomes targeted to improve mental health functioning. Significant treatment effects were found on both social skills and mental health functioning. However, although program effects on mental health functioning were significant for both low and high risk status groups, program effects on social skills were only significant for low risk status students, suggesting that different mechanisms may underlie program effects for high and low risk status students. Overall the results of this study, one of the first to assess directly the effects of a school-based program on mental health functioning in a low or middle income country, provide some support for the value of using school-based programs to address the substantial child mental health treatment gap found in low- and middle-income countries.

16.
Ann Pharmacother ; 50(9): 758-67, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27281301

RESUMO

OBJECTIVE: To review insights gained in the past several years about hereditary antithrombin (AT) deficiency and to outline approaches to the management of patients with AT deficiency in the acute and chronic settings. DATA SOURCES: An extensive literature search of Scopus (January 2008-April 2016) was performed for the terms congenital antithrombin deficiency, inherited antithrombin deficiency, or hereditary antithrombin deficiency Additional references were identified by reviewing literature citations. STUDY SELECTION: All relevant English-language case reports, reviews, clinical studies, meeting abstracts, and book chapters assessing hereditary AT deficiency were included. DATA SYNTHESIS: AT deficiency significantly increases the risk of venous thromboembolism (VTE). The risk of VTE is particularly high during pregnancy, the postpartum period, and following major surgery. Effective clinical management includes determination of the appropriate type and duration of antithrombotic therapy (ie, AT replacement for acute situations) while minimizing the risk of bleeding. For persons newly diagnosed with AT deficiency, age, lifestyle, concurrent medical conditions, family history, and personal treatment preferences can be used to individualize patient management. Patients should be informed of the risks associated with hormonal therapy, pregnancy, surgical procedures, and immobility, which further increase the risk of VTE in patients with AT deficiency. CONCLUSION: AT deficiency poses the highest risk for VTE among the hereditary thrombophilias, often requiring long-term anticoagulation. Undertaking an evaluation for hereditary thrombophilia is controversial; however, a diagnosis of VTE in association with AT deficiency can have management implications. An important treatment option for patients with this disorder in high-risk situations is AT concentrate.


Assuntos
Anticoagulantes/uso terapêutico , Deficiência de Antitrombina III/diagnóstico , Deficiência de Antitrombina III/tratamento farmacológico , Coagulação Sanguínea/efeitos dos fármacos , Fibrinolíticos/uso terapêutico , Tromboembolia Venosa/tratamento farmacológico , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Deficiência de Antitrombina III/sangue , Deficiência de Antitrombina III/complicações , Feminino , Fibrinolíticos/administração & dosagem , Fibrinolíticos/efeitos adversos , Hemorragia/sangue , Hemorragia/etiologia , Humanos , Masculino , Medicina de Precisão , Gravidez , Fatores de Risco , Tromboembolia Venosa/sangue , Tromboembolia Venosa/etiologia
17.
Andrology ; 12(3): 618-623, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37615496

RESUMO

INTRODUCTION: Premature ejaculation (PE) is a prevalent sexual dysfunction in men that greatly affects their quality of life. In PE, the duration of sexual performance is considered an important aspect. However, a self-estimated value of intravaginal ejaculation latency time (perceived IELT, PIELT) as a criterion for diagnosis has not been specified. AIM: This study aimed to determine the validity and a threshold value for PIELT in PE diagnosis. METHOD: In our cross-sectional study, we recruited 550 men from March 2019 to January 2020 and interviewed them regarding their general demographic characteristics, sexual habits, PIELT and completed a premature ejaculation diagnostic tool (PEDT) questionnaire. Eventually, a combination of a clinical diagnosis and PEDT score was used, in which those with PEDT ≥ 11 and diagnosed with possible PE were assigned to the final PE(+) group; those with PEDT score ≤ 8 and diagnosed with no PE were included in the final PE(-) group. RESULTS: Men PE(-) had more frequent sexual intercourse (9.74 ± 5.38 vs. 6.69 ± 5.38 episodes per month, p < 0.001) and had higher marriage rate (72.7% vs. 60.4%, p = 0.002) than PE(+) patients. No significant difference was noted regarding age, smoking habit, age of first sexual experience, and number of sexual partners between the two groups. The mean PIELT of control subjects and PE(+) patients were 11.69 ± 6.83 min and 2.01 ± 1.21 min, respectively. On receiver operating characteristic curve analysis, the cut-off value of PIELT of 3.75 min can be used to distinguish PE men (area under the curve = 0.982, sensitivity/specificity = 0.961/0.909), which means that men with a PIELT ≤ 3.5 min is suggestive of PE. CONCLUSION: The impact of PE is dramatic both from a social and a personal perspective. PE(+) patients married significantly less and have significantly lower sexual activity compared to a PE(-) population. Furthermore, a PIELT of ≤ 3.5 min predicts PE demonstrating the need to revise its taxonomy and definition.


Assuntos
Ejaculação , Ejaculação Precoce , Masculino , Humanos , Vietnã , Qualidade de Vida , Estudos Transversais
18.
ACS Appl Mater Interfaces ; 16(28): 36157-36167, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38973633

RESUMO

In situ-forming biocompatible hydrogels have great potential in various medical applications. Here, we introduce a pH-responsive, self-healable, and biocompatible hydrogel for cell scaffolds and the development of a tumor spheroid phantom for magnetic resonance imaging. The hydrogel (pMAD) was synthesized via amino-yne click chemistry between poly(2-methacryloyloxyethyl phosphorylcholine-co-2-aminoethylmethacrylamide) and dialkyne polyethylene glycol. Rheology analysis, compressive mechanical testing, and gravimetric analysis were employed to investigate the gelation time, mechanical properties, equilibrium swelling, and degradability of pMAD hydrogels. The reversible enamine and imine bond mechanisms leading to the sol-to-gel transition in acidic conditions (pH ≤ 5) were observed. The pMAD hydrogel demonstrated potential as a cellular scaffold, exhibiting high viability and NIH-3T3 fibroblast cell encapsulation under mild conditions (37 °C, pH 7.4). Additionally, the pMAD hydrogel also demonstrated the capability for in vitro magnetic resonance imaging of glioblastoma tumor spheroids based on the chemical exchange saturation transfer effect. Given its advantages, the pMAD hydrogel emerges as a promising material for diverse biomedical applications, including cell carriers, bioimaging, and therapeutic agent delivery.


Assuntos
Química Click , Hidrogéis , Imageamento por Ressonância Magnética , Hidrogéis/química , Hidrogéis/síntese química , Camundongos , Animais , Células NIH 3T3 , Humanos , Esferoides Celulares/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Alicerces Teciduais/química , Imagens de Fantasmas
19.
Humanit Soc Sci Commun ; 10(1): 329, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37361101

RESUMO

The present study examines the roles of internal communication (IC), job engagement (JE), organisation engagement (OE) and job satisfaction (JS) in producing employee loyalty (EL) based on the social exchange theory. This study employed an online questionnaire-based survey design to collect data from 255 respondents from higher education institutions (HEIs) in Binh Duong province using convenience and snowball sampling techniques. Data analyses and hypothesis testing were carried out using the partial least squares structural equation modelling (PLS-SEM). The findings show that all relationships are significantly validated, except for the JE-JS relationship. Our work is the first to investigate employee loyalty in the HEI context of an emerging economy such as Vietnam by incorporating internal communication, employee engagement (including job and organisation engagement) and job satisfaction to develop and validate a research model for the study. This study is expected to contribute to the theory and advance our understanding of different mechanisms that job engagement, organisation engagement and job satisfaction can play in the relationship between internal communication and employee loyalty.

20.
Future Virol ; 18(8): 501-516, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38051989

RESUMO

Aim: To generate mRNAs encoding conserved regions within SARS-CoV-2 ORF1ab which can induce strong T-cell responses to overcome the immune invasion of newly emergent variants. Methods: We selected two conserved regions with a high density of T-cell epitopes using immunoinformatics for mRNA synthesis. The ability of testing mRNAs to activate T cells for IFN-γ production was examined by an ELISpot assay and flow cytometry. Results: Two synthesized mRNAs were successfully translated in MDA-MB-231 cells and had comparable potency to the spike mRNA to induce CD4+ and CD8+ T-cell responses in peripheral blood mononuclear cells in 29 out of 34 participants. Conclusion: This study provides a proof-of-concept for the use of SARS-CoV-2 conserved regions to develop booster vaccines capable of eliciting T-cell-mediated immunity.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA