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1.
Anal Chem ; 96(15): 5897-5905, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38557023

RESUMO

Current diagnostic methods for thyroid diseases, including blood tests, ultrasound, and biopsy, always have difficulty diagnosing thyroiditis accurately, occasionally mistaking it for thyroid cancer. To address this clinical challenge, we developed Ox-PGP1, a novel fluorescent probe realizing rapid, noninvasive, and real-time diagnostic techniques. This is the first imaging tool capable of noninvasively distinguishing between thyroiditis and thyroid cancer. Ox-PGP1 was introduced as a fluorescent probe custom-built for the specific detection and quantification of pyroglutamate aminopeptidase 1 (PGP-1), a known pivotal biomarker of inflammation. Ox-PGP1 overcame the disadvantages of traditional enzyme-responsive fluorescent probes that relied on the intramolecular charge transfer (ICT) mechanism, including the issue of high background fluorescence, while offering exceptional photostability under laser irradiation. The spectral properties of Ox-PGP1 were meticulously optimized to enhance its biocompatibility. Furthermore, the low limit of detection (LOD) of Ox-PGP1 was determined to be 0.09 µg/mL, which demonstrated its remarkable sensitivity and precision. Both cellular and in vivo experiments validated the capacity of Ox-PGP1 for accurate differentiation between normal, inflammatory, and cancerous thyroid cells. Furthermore, Ox-PGP1 showed the potential to rapidly and sensitively differentiate between autoimmune thyroiditis and anaplastic thyroid carcinoma in a mouse model, achieving results in just 5 min. The successful design and application of Ox-PGP1 represent a substantial advancement in technology over traditional diagnostic approaches, potentially enabling earlier interventions for thyroid diseases.


Assuntos
Neoplasias da Glândula Tireoide , Tireoidite , Animais , Camundongos , Piroglutamil-Peptidase I , Corantes Fluorescentes , Tireoidite/patologia , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Imagem Óptica
2.
Protein Expr Purif ; 221: 106505, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38768672

RESUMO

Protein reagents are essential resources for several stages of drug discovery projects from structural biology and assay development through lead optimization. Depending on the aim of the project different amounts of pure protein are required. Small-scale expressions are initially used to determine the reachable levels of production and quality before scaling up protein reagent supply. Commonly, amounts of several hundreds of milligrams to grams are needed for different experiments, including structural investigations and activity evaluations, which require rather large cultivation volumes. This implies that cultivation of large volumes of either transiently transfected cells or stable pools/stable cell lines is needed. Hence, a production process that is scalable, speeds up the development projects, and increases the robustness of protein reagent quality throughout scales. Here we present a protein production pipeline with high scalability. We show that our protocols for protein production in Chinese hamster ovary cells allow for a seamless and efficient scale-up with robust product quality and high performance. The flexible scale of the production process, as shown here, allows for shorter lead times in drug discovery projects where there is a reagent demand for a specific protein or a set of target proteins.


Assuntos
Reatores Biológicos , Cricetulus , Plasmídeos , Proteínas Recombinantes , Células CHO , Animais , Proteínas Recombinantes/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/metabolismo , Plasmídeos/genética , Plasmídeos/metabolismo , Cricetinae
3.
Inorg Chem ; 63(21): 10031-10041, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38752590

RESUMO

Ferroelectric materials, leveraging an inherent built-in electric field, are excellent in suppressing electron-hole recombination. However, the reliance solely on bulk polarization remains insufficient in enhancing carriers' separation and migration, limiting their practical application in photocatalytic overall water splitting (POWS). To address this, we incorporated cations with ns2 lone pairs (P3+, As3+, Sb3+, and Bi3+) into ferroelectric semiconductors, successfully constructing 44 ß-AIBIIIO2 photocatalysts with dual polarization. Through rigorous first-principles calculations and screenings for stability, band characteristics, and polarization, we identified four promising candidates: ß-LiSbO2, ß-NaSbO2, ß-LiBiO2, and ß-TlBiO2. Within these materials, lone pairs induce local polarization in the xy-plane. Additionally, out of the plane, there is robust bulk polarization along the z-direction. This synergistic effect of the combined local and bulk polarization significantly improves the separation efficiency of electron-hole pairs. Explicitly, the electron mobility of the four candidates ranges from 105 to 106 cm2 s-1 V-1, while the hole mobility also increases significantly compared to single-phase polarized materials, up to 106 cm2 s-1 V-1. Notably, ß-TlBiO2 is predicted to achieve a solar-to-hydrogen (STH) efficiency of 17.2%. This study not only offers insights for water-splitting catalyst screening but also pioneers a path for electron-hole separation through the dual polarization strategy.

4.
Anal Chem ; 95(32): 12089-12096, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37525359

RESUMO

Traditional molecular imaging tools used for detecting liver diseases own several drawbacks, such as poor optical performance and limited applicability. Monitoring the concentration of leucine aminopeptidase (LAP), which is closely related to liver diseases such as liver cancer and liver injury, and analyzing it in diagnosis, drug evaluation, and surgical treatment is still a challenging task. Herein, we construct an intramolecular charge-transfer mechanism-based, ultrasensitive, near-infrared fluorescent probe (LAN-lap) for dynamic monitoring of LAP fluctuations in living systems. LAN-lap, with high specificity, stability, sensitivity, and water solubility, can achieve in vitro monitoring of LAP through both fluorescence and colorimetric methods. Moreover, LAN-lap can successfully be used for the localization imaging of endogenous LAP, confirming the upregulation of LAP expression in liver cancer and liver injury cells. In addition, LAN-lap can realize the imaging of liver tumors in living organisms. Meanwhile, it can intuitively present the degree of drug-induced liver injury, achieving semi-quantitative imaging evaluation of the hepatotoxicity of two drugs. Furthermore, LAN-lap can track liver cancer tumors in mice with peritoneal metastasis and can assist in fluorescence-guided surgical resection of liver cancer tumors. This multifunctional LAN-lap probe could play an important role in facilitating simultaneous diagnoses, imaging, and synergistic surgical navigation to achieve better point-of-care therapeutic efficacy.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Neoplasias Hepáticas , Animais , Camundongos , Leucil Aminopeptidase/metabolismo , Avaliação de Medicamentos , Corantes Fluorescentes , Neoplasias Hepáticas/diagnóstico por imagem , Imagem Molecular
5.
Anal Chem ; 95(5): 2949-2957, 2023 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-36695319

RESUMO

Fluorescence imaging-guided diagnostics is one of the most promising approaches for facile detection of tumors in situ owing to its simple operation and non-invasiveness. As a crucial biomarker for primary ovarian cancers, ß-galactosidase (ß-gal) has been demonstrated to be the significant molecular target for visualization of ovarian tumors. Herein, a membrane-permeable fluorescent chemosensor (namely, LAN-ßgal) was synthesized for ß-gal-specific detection using the d-galactose residue as a specific recognition unit and LAN-OH (ΦF = 0.47) as a fluorophore. After ß-gal was digested, the fluorescence of the initially quenched LAN-ßgal (ΦF < 0.001) was enhanced by up to more than 2000-fold, which exceeded the fluorescence enhancement of other previously reported probes. We also demonstrated that the chemosensor LAN-ßgal could visualize endogenous ß-gal and distinguish ovarian cancer cells from normal ovarian cells. Further, the chemosensor LAN-ßgal was successfully applied to visualize the back tumor-bearing mouse model and peritoneal metastatic ovarian cancer model in vivo. More importantly, through in situ spraying, the proposed chemosensor was successfully employed to assist in the surgical resection of ovarian cancer tumors due to its high tumor-to-normal (T/N) tissue fluorescence ratio of 218. To the best of our knowledge, this is the highest T/N tissue fluorescence ratio ever reported. We believe that the LAN-ßgal chemosensor can be utilized as a new tool for the clinical diagnosis and treatment of ovarian cancer.


Assuntos
Corantes Fluorescentes , Neoplasias Ovarianas , Humanos , Camundongos , Animais , Feminino , Corantes Fluorescentes/química , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/cirurgia , Microscopia de Fluorescência , Biomarcadores , Modelos Animais de Doenças , beta-Galactosidase/química
6.
Anal Chem ; 95(48): 17577-17585, 2023 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-38050673

RESUMO

Early detection and effective treatment of thyroid cancer are vital due to the aggressiveness and high mortality rate of the cancer. Nevertheless, the exploration of dipeptidyl peptidase-IV (DPP-IV) as a biomarker for thyroid diseases has not been widely conducted. In this study, we developed a novel non-π-conjugated near-infrared fluorescent probe, MB-DPP4, specifically designed to visualize and detect endogenous DPP-IV. Traditional DPP-IV-specific fluorescent probes rely primarily on the intramolecular charge transfer mechanism. For this reason, these probes are often hampered by high background levels that can inhibit their ability to achieve a fluorescence turn-on effect. MB-DPP4 successfully surmounts several drawbacks of traditional DPP-IV probes, boasting unique features such as exceptional selectivity, ultrahigh sensitivity (0.29 ng/mL), innovative structure, low background, and long-wavelength fluorescence. MB-DPP4 is an "off-on" chemosensor that exhibits strong fluorescence at 715 nm and releases a methylene blue (MB) fluorophore upon interacting with DPP-IV, resulting in a visible color change from colorless to blue. Given these remarkable attributes, MB-DPP4 shows great promise as a versatile tool for advancing research on biological processes and for evaluating the physiological roles of DPP-IV in living systems. Finally, we conducted a comprehensive investigation of DPP-IV expression in human serum, urine, thyroid cells, and mouse thyroid tumor models. Our findings could potentially establish a foundation for the early diagnosis and treatment of thyroid diseases.


Assuntos
Dipeptidil Peptidase 4 , Neoplasias da Glândula Tireoide , Animais , Camundongos , Humanos , Dipeptidil Peptidase 4/metabolismo , Corantes Fluorescentes/química , Detecção Precoce de Câncer , Neoplasias da Glândula Tireoide/diagnóstico por imagem
7.
Cell Mol Biol (Noisy-le-grand) ; 69(15): 148-153, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38279465

RESUMO

The objective of this study was to explore the correlation between vaginal microecological imbalance and the expression of related inflammatory factors in pregnant women with group B streptococcus (GBS) infection and pregnancy outcomes. For this purpose, 100 GBS-positive pregnant women were recruited as the experimental group, and 100 GBS-negative pregnant women were recruited as the controls. The balance of vaginal microecology of pregnant women in different groups was compared. Results showed that the probability of vaginal microecological imbalance in the experimental group was much higher than against the controls. Fasting venous blood was drawn from the pregnant women in two groups. After centrifugation, the expression levels of interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), and interleukin-1ß (IL-1ß) in serum were detected. It was found that the expression levels of IL-6, IL-1ß, and TNF-α in the experimental group were higher than against the controls. After delivery, it suggested that the incidence of premature delivery, neonatal infection, premature rupture of membranes, and other adverse childbirth in the experimental group was much higher in contrast to the controls, up to 87%. In conclusion, GBS infection can increase the incidence of vaginal microecological imbalance and the expression of serum inflammatory factors in pregnant women, and it can greatly raise the incidence of adverse pregnancy outcomes.


Assuntos
Complicações Infecciosas na Gravidez , Infecções Estreptocócicas , Recém-Nascido , Gravidez , Feminino , Humanos , Resultado da Gravidez , Gestantes , Interleucina-6 , Fator de Necrose Tumoral alfa , Streptococcus agalactiae , Infecções Estreptocócicas/epidemiologia , Inflamação
8.
J Appl Microbiol ; 134(1)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36626755

RESUMO

AIMS: Extensively drug-resistant (XDR) Acinetobacter baumannii poses a severe threat to public health due to its ability to form biofilms and persister cells, which contributes to critical drug resistance and refractory device-associated infections. A novel strategy to alleviate such an emergency is to identify promising compounds that restore the antimicrobial susceptibility of existing antibiotics against refractory infections. METHODS AND RESULTS: Here, we found a significant synergy among three combinations of SPR741, clarithromycin and erythromycin with a potent antimicrobial activity against XDR A. baumannii (SPR741/CLA/E at 8/10/10 µg ml-1 for XDR AB1069 and at 10/16/10 µg ml-1 for XDR AB1208, respectively). Moreover, the triple combination therapy exhibits a significant antipersister and antibiofilm effect against XDR strains. Mechanistic studies demonstrate that SPR741 may promote intracellular accumulation of macrolides by permeabilizing the outer membrane as well as disrupting membrane potential and further enhance the quorum sensing inhibition activity of the macrolides against XDR A. baumannii and its biofilms. In addition, the triple combination of SPR741 with clarithromycin and erythromycin was not easy to induce resistance in A. baumannii and had effective antimicrobial activity with low toxicity in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: Collectively, these results reveal the potential of SPR741 in combination with clarithromycin and erythromycin as a clinical therapy for refractory infections caused by XDR A. baumannii.


Assuntos
Acinetobacter baumannii , Claritromicina , Claritromicina/farmacologia , Eritromicina/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Biofilmes , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana
9.
Int Heart J ; 64(5): 935-944, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37778997

RESUMO

A certain dosage of cyclophosphamide (CYP) in clinical applications contributes to severe cardiotoxicity. Herein, this study explored the impact of adipose-derived mesenchymal stem cell (AdMSC)-exosomes (Exos) on CYP-induced cardiotoxicity.AdMSCs and AdMSCs-Exos were isolated and identified. CYP was utilized for developing a cardiotoxicity rat model, after which blood was collected and then the serum contents of cardiac injury-related indexes (creatine kinase-MB, lactate dehydrogenase, aspartate aminotransferase, and alkaline phosphatase) were detected with enzyme-linked immunosorbent assay kits. Oxidative stress (OS)-related indicators were measured with the corresponding kits. Myocardial pathological changes and collagen fibrosis were tested with hematoxylin-eosin and Masson staining, and apoptosis-related and autophagy-related proteins in rat cardiac tissues with immunohistochemistry and Western blot assays, respectively.AdMSCs and AdMSCs-Exos were successfully isolated. AdMSCs-Exos could target rat hearts. AdMSCs-Exos improved cardiac function and diminished the content of the cardiac injury-related indexes in CYP rats. In addition, AdMSCs-Exos reduced CYP-induced cardiac fibrosis, OS, apoptosis, and autophagy in rats.AdMSCs-Exos alleviated CYP-induced cardiotoxicity in rats via the repression of OS, apoptosis, and autophagy.


Assuntos
Exossomos , Células-Tronco Mesenquimais , Ratos , Animais , Cardiotoxicidade/etiologia , Cardiotoxicidade/prevenção & controle , Exossomos/metabolismo , Células-Tronco Mesenquimais/metabolismo , Apoptose , Ciclofosfamida/toxicidade , Ciclofosfamida/metabolismo
10.
BMC Nurs ; 22(1): 1, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36624445

RESUMO

BACKGROUND: The flipped classroom (FC) method is becoming increasingly popular in China's nursing education. It is an important breakthrough improvement in the quality of learning in nursing education reforms. PURPOSE: This study aimed to determine the effects of blended task-oriented flipped classroom (TFC) on nursing students undertaking the Fundamentals of Nursing course. METHODS: A pre-and post-test quasi-experimental design was adopted. This study was conducted in the Autumn semester, 2021 academic year in a Chinese university. Using cluster sampling technique, this study enrolled second-year undergraduate nursing students from six classess who were studying Fundamentals of Nursing course. A blended TFC was developed and implemented with three classes (experimental group: n = 152). In-class traditional lectures were applied to the other three classes (control group: n = 151). The Self-Directed Learning Instrument, Problem-Solving Inventory, and California Critical Thinking Disposition Inventory were used to evaluate students' learning outcomes, and final examinations were conducted at the end of after course. In addition, students in the flipped classroom group were required to answer five open-ended questions concerning their flipped classroom learning experiences. RESULTS: Students in the experimental group showed significant improvement in academic performance compared to those in the control group (p = 0.001). Considering total scale and factors, students in the experimental grouped recorded significantly higher scores in self-directed learning ability, problem-solving skills, and critical thinking ability compared to those in the control group (p < 0.05). Furthermore, improved abilities and skills such as team cooperation, communication, presentation, identifying /solving clinical problems, and accountability were reported. CONCLUSION: A blended TFC teaching approach positively impacted students' core competencies and improved learning outcomes in the Fundamentals of Nursing course.

11.
Turk J Med Sci ; 53(5): 1185-1193, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38813035

RESUMO

Background/aim: To better optimize the inactivated vaccine-induced immune response and improve vaccine protection efficiency, a preliminary study was conducted on the influencing factors of producing neutralizing antibody (NAb) titers against the inactivated coronavirus disease 2019 (COVID-19) vaccine. Materials and methods: A total of 91 health care volunteers were enrolled from the Immunology Division of the Laboratory Department of Chongqing General Hospital from February to March 2021. The study had a cross-sectional design. All of the volunteers were scheduled to receive a complete dose regimen of the inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine and the vaccination interval between 2 doses was 14 days. Clinical and laboratory features were collected for further analysis. Results: The NAb titers gradually increased after COVID-19 vaccination, and 72.53% (n = 66) of the volunteers had NAbs after the second dose. Eight variables, including CD16+CD56+ NK cell level before the first dose (HR = 0.94, p = 0.02), CD16+CD56+ NK cell level after the second dose (HR = 0.94, p = 0.03), interleukin (IL)-2 level before the first dose (HR = 2.09, p = 0.05), mean corpuscular volume (HR = 0.86, p = 0.02), serum urea level (HR = 0.69, p = 0.05), increment of CD19+ B cells (HR = 0.86, p = 0.03), increment of CD4+/CD8+ T cells (HR = 0.21, p = 0.03), and increment of the IL-6 level (HR = 0.75, p = 0.04) demonstrated a correlation with the NAb titers after COVID-19 vaccination. In the multivariate logistical regression analysis, the serum urea level (HR = 2.32, P = 0.03) and increment of CD19+ B cells (HR = 1.96, p = 0.03) were positively correlated with the NAb titers. The principal component analysis effectively distinguished the response after COVID-19 vaccination. The Pearson correlation analysis indicated that the CD19+ B cell level (r = 0.23, p < 0.001) and IL-2 (r = 0.24, p < 0.001) and IL-6 levels (r = 0.22, p < 0.001) were weakly positively correlated with the concentration of NAbs. Conclusion: The NAbs titers of the inactivated vaccines were positively correlated with the ratio of CD19+ B cell, IL-6, and IL-2 levels in the serum, which provide clinical guidance for inactivated SARS-CoV-2 vaccines.


Assuntos
Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Vacinas de Produtos Inativados , Humanos , Masculino , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Feminino , COVID-19/prevenção & controle , COVID-19/imunologia , Adulto , Estudos Transversais , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/administração & dosagem , SARS-CoV-2/imunologia , Pessoa de Meia-Idade , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacinação , Células Matadoras Naturais/imunologia
12.
Appl Microbiol Biotechnol ; 106(7): 2689-2702, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35338386

RESUMO

Staphylococcus aureus is a major human pathogen, and the appearance of methicillin-resistant S. aureus (MRSA) renders S. aureus infections more challenging to treat. Therefore, new antimicrobial drugs are urgently needed to combat MRSA infections. Drug repurposing is an effective and feasible strategy. Here, we reported that the clinically approved anti-hepatitis C virus drug simeprevir had strong antibacterial activity against MRSA, with a minimum inhibitory concentration of 2-8 µg/mL. Simeprevir did not easily induce in vitro resistance. In addition, simeprevir significantly prevented S. aureus biofilm formation. Furthermore, simeprevir displayed limited toxicity in in vitro and in vivo assays. Moreover, simeprevir showed synergistic antimicrobial effects against both type and clinical strains of S. aureus. Simeprevir combined with gentamicin effectively reduced the bacterial burden in an MRSA-infected subcutaneous abscess mouse model. Results from a series of experiments, including membrane permeability assay, membrane potential assay, intracellular ATP level assay, and electron microscope observation, demonstrated that the action of simeprevir may be by disrupting bacterial cell membranes. Collectively, these results demonstrated the potential of simeprevir as an antimicrobial agent for the treatment of MRSA infections. KEY POINTS: • Simeprevir showed strong antibacterial activity against MRSA. • The antibacterial mechanism of simeprevir was mediated by membrane disruption and intracellular ATP depletion. • In vitro and in vivo synergistic antimicrobial efficacy between simeprevir and gentamicin was found.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Trifosfato de Adenosina , Animais , Antibacterianos/farmacologia , Bactérias , Gentamicinas/farmacologia , Camundongos , Testes de Sensibilidade Microbiana , Simeprevir/farmacologia , Simeprevir/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus
13.
Lett Appl Microbiol ; 75(3): 655-666, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35218030

RESUMO

Due to the increasing rate of antibiotic resistance and the emergence of persister cells of Gram-negative pathogenic bacteria, the development of new antibacterial agents is urgently needed to deal with this problem. Our results indicated that both newly identified small molecule STK-35 and its derivative STK-66 exhibited effective antibacterial properties against a variety of Gram-negative pathogens including Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. The minimal inhibitory concentrations and minimal bactericidal concentrations ranges were 0·0625-8 µg ml-1 and 0·125-16 µg ml-1 , respectively, while no haemolytic activity and mammalian cell cytotoxicity were observed. The time-killing assays showed STK-35/66 had strong bactericidal activity against Gram-negative pathogens. STK-35/66 also showed different degrees of synergistic antibacterial activity with conventional antibiotics and exhibited persister cells killing activity. Moreover, STK-35/66 effectively eradicated the pre-formed biofilms of P. aeruginosa and A. baumannii. In addition, STK-35/66 significantly increased the survival rate of E. coli infected mice and induced a decrease in bacterial load of the peritonitis model. In nutshell, these results suggested that STK-35/66 possessed antimicrobial activity against Gram-negative pathogenic bacteria in vitro and in vivo, which could be considered as potential substitutes for the treatment of Gram-negative pathogenic infections after further structure optimization.


Assuntos
Antibacterianos , Escherichia coli , Animais , Antibacterianos/química , Bactérias Gram-Negativas , Mamíferos , Camundongos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa
14.
Inorg Chem ; 60(3): 1367-1379, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33434017

RESUMO

Based on first-principles calculations with the DFT + U method, the couplings of lattice, charge, spin, and electronic behaviors underlying the Eu-Mn charge transfer in a strongly correlated system of EuMnO3 were investigated. The potential valence transition from Eu3+/Mn3+ to Eu2+/Mn4+ was observed in a compressed lattice with little distortions, which is achieved under hydrostatic pressure and external strain. The intraplane antiferromagnetism (AFM) of Mn is proved to be instrumental in the emergence of Eu2+. Furthermore, we calculated the magnetic exchange interactions within two equilibrium structures of Eu3+Mn3+O3 and Eu2+Mn4+O3. Mn-Mn ferromagnetic exchange in the ab-plane is enhanced strongly in the Eu2+Mn4+O3 structure, contributing to the existence of mixed states. The versatile electronic structures were obtained within the Eu2+Mn4+O3 phase by imposing different magnetic configurations on the Eu and Mn sublattice, attributed to the coupling of charge transfer and magnetic orderings. It is found that the intraplane ferromagnetic ordering of Mn leads to a metallic electronic structure with the coexistence of Eu2+ and Eu3+, while the intraplane AFM Mn spin ordering leads to insulating states only with Eu2+. Notably, a half-metallic characteristic emerges at the magnetic ground state of CF ordering (C-type AFM for the Eu sublattice and ferromagnetic for the Mn sublattice), which makes such a supposed phase more intriguing than the conventional experimental phase. Additionally, the mixture of delocalized 4f with 5d states of Eu in the background of Mn 3d and O 2p orbitals implies a pathway of Eu 4f 5d ↔ O 2p ↔ Mn 3d for charge transfer between Eu and Mn. Our calculation shows that the Eu-Mn charge transfer could be expected in compressed EuMnO3 and the introduction of Eu2+ 4f states near the Fermi level plays an important role in manipulating the interlinks of charge and spin together with electronic behaviors.

15.
Curr Microbiol ; 79(1): 12, 2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-34905092

RESUMO

Pseudomonas aeruginosa is a ubiquitous bacterium found in hospitals and the surrounding environment. The ability of P. aeruginosa to form biofilms confers high-level resistance to antibiotics, and the persister cells formed in the presence of high antibacterial drug concentrations make P. aeruginosa-related infections more refractory. Further, there rarely is an effective antimicrobial alternative when biofilm- and persister cell-targeting treatment fails. Using a high-throughput screening assay, we previously identified fluoroquinolones sitafloxacin, prulifloxacin, and tosufloxacin as well as aminoglycoside sisomicin among FDA-approved drugs with significant bactericidal activity against P. aeruginosa. In addition, in our current study, these antibiotics exhibited an effective time- and dose-dependent eradication effects against the preformed biofilms of P. aeruginosa at the concentrations of 2-4 µM. These agents also exhibited bactericidal efficacy against CCCP-induced P. aeruginosa persister cells with the viable cell count decreased from 9.14 log10 CFU/mL to 6.15 (sitafloxacin), 7.59 (prulifloxacin), 4.27 (tosufloxacin), and 6.17 (sisomicin) log10 CFU/mL, respectively, following 4 h of treatment. Furthermore, sisomicin was also effective against conventional antibiotics induced persister cells in a time-dependent manner within 24 h. In addition, we confirmed the in vivo anti-biofilm efficacy of the identified antibiotics in a subcutaneous implantation biofilm-related infection model. Tosufloxacin exhibited the greatest in vivo bactericidal activity against P. aeruginosa biofilms with a reduction of 4.54 ΔLog10 CFU/mL compared to the vehicle group, followed by prulifloxacin, sitafloxacin, and sisomicin. Taken together, our results indicate that sitafloxacin, prulifloxacin, tosufloxacin, and sisomicin have great potential as alternatives for the treatment of refractory infections caused by P. aeruginosa biofilms and persister cells.


Assuntos
Anti-Infecciosos , Pseudomonas aeruginosa , Antibacterianos/farmacologia , Biofilmes , Dioxolanos , Reposicionamento de Medicamentos , Fluoroquinolonas/farmacologia , Testes de Sensibilidade Microbiana , Naftiridinas , Piperazinas , Sisomicina
16.
Anal Bioanal Chem ; 412(26): 7211-7217, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32757064

RESUMO

Cysteine (Cys) takes part in redox balance in cells as an antioxidant, and imbalance of Cys content in the body can cause a variety of diseases. It is very important to develop a new fluorescent chemosensor to specifically detect Cys intracellular. In this work, a novel NIR fluorescent probe was constructed based on 3-ethyl-1,1,2-trimethyl-1H-benzo[e]indol-3-ium iodide and 5-(4-hydroxyphenyl)furan-2-carbaldehyde. The probe could selectively detect Cys in the presence of homocysteine (Hcy), glutathione (GSH), and other interferences. It also had a number of advantages, including nucleolus-targeting ability, long fluorescence emission wavelength (685 nm), low detection limit (56 nM), and large Stokes shift (172 nm). The probe was employed to enable visualization of Cys in HepG2 cells, and due to its good response in viscous environment, the probe could also locate nucleoli intracellular.


Assuntos
Cisteína/análise , Corantes Fluorescentes/química , Espectrometria de Fluorescência/métodos , Células Hep G2 , Humanos , Limite de Detecção , Oxirredução
17.
Phys Chem Chem Phys ; 22(9): 4905-4915, 2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-32073064

RESUMO

Based on first-principles calculations, multiferroic properties of orthorhombic manganites (RMnO3, R = La-Lu) with E-type ground state have been achieved by lanthanide contraction (chemical pressure) and/or external strain. Our research demonstrates that a smaller R radius within the octahedral voids in RMnO3 results in the increase in the tilts of the octahedra but only a gentle change in the Jahn-Teller (JT) distortion. The reduction of the intraplane octahedral rotation angle and the narrowed eg states and lifting t2g band edge are mainly responsible for the intraplane magnetic transition from ferromagnetic (La-Gd) to zigzag-like spin arrangement (Ho-Lu). In turn, the center-broken E-type RMnO3 bulk characterizes the dominated electronic polarization behavior, benefiting from their distortion response to small R substitution, which gives rise to the strong magnetoelectricity. Subsequently, we have figured out the strain strategy for obtaining an E-type transition in light rare-earth manganites (La-Gd) by imposing a series of hypothetical strains, where the small intraplane rotation angle (Θ) and large JT distortion favor the small aspect ratios of a/b and c/b, respectively. The strained LaMnO3 and GdMnO3 achieve E-type transitions successfully by imposing a modest compressive strain along the a- and c-axes and remaining free along the b-direction. Simultaneously, their polarization behaviors were comparatively studied. It was found that the size of the A-site rare-earth ions has a great influence on the external strain response, in addition to its effect on the magnetic phase transition.

18.
J Clin Lab Anal ; 34(7): e23301, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32196744

RESUMO

BACKGROUND: The information on mortality after an acute stroke patient is still limited. OBJECTIVES: The aim of this study was to investigate the prognostic potential of procalcitonin (PCT) serum levels in acute ischemic stroke. METHODS: A total of 748 patients were enrolled in this study. Prognostic potential of PCT was evaluated by Kaplan-Meier analysis and multivariable Cox hazard regression analyses. RESULTS: Procalcitonin levels were found to be significantly higher in acute ischemic stroke patients who died in 30 days than those who survived. Univariate logistic regression analysis showed that PCT was significantly associated with 30-day mortality, and Cox regression analysis revealed that PCT was a strong predictor of 30-day overall mortality. Kaplan-Meier analysis revealed that overall cumulative 30-day mortality was significantly higher in those with PCT levels >1.5 ng/mL when compared to those with PCT levels <1.5 ng/mL. CONCLUSIONS: Procalcitonin is a significant independent prognostic marker of 30-day mortality after the one set of acute ischemic stroke.


Assuntos
Biomarcadores/sangue , AVC Isquêmico/sangue , AVC Isquêmico/mortalidade , Pró-Calcitonina/sangue , Idoso , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos
19.
Cancer Immunol Immunother ; 67(7): 1079-1090, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29687231

RESUMO

Antibodies targeting PD-1 have been demonstrated durable anti-cancer activity in certain cancer types. However, the anti-PD-1 antibodies are less or not efficacious in many situations, which might be attributed to co-expression of multiple inhibitory receptors or presence of immunosuppressive cells in the tumor microenvironment. Most of the anti-PD-1 antibodies used in clinical studies are of IgG4 isotype with the S228P mutation (IgG4S228P). The functional impact by the interaction of anti-PD-1 IgG4S228P antibody with Fc gamma receptors (FcγRs) is poorly understood. To assess the effects, we generated a pair of anti-PD-1 antibodies: BGB-A317/IgG4S228P and BGB-A317/IgG4-variant (abbreviated as BGB-A317), with the same variable regions but two different IgG4 Fc-hinge sequences. There was no significant difference between these two antibodies in binding to PD-1. However, BGB-A317/IgG4S228P binds to human FcγRI with high affinity and mediates crosslinking between PD-1 and FcγRI. In contrast, BGB-A317 does neither. Further cell-based assays showed that such crosslinking could reverse the function of an anti-PD-1 antibody from blocking to activating. More importantly, the crosslinking induces FcγRI+ macrophages to phagocytose PD-1+ T cells. In a mouse model transplanted with allogeneic human cancer cells and PBMCs, BGB-A317 showed significant tumor growth inhibition, whereas BGB-A317/IgG4S228P had no such inhibition. Immunohistochemistry study revealed an inverse correlation between FcγRI+ murine macrophage infiltration and the density of CD8+PD-1+ human T cells within tumors in the BGB-A317/IgG4S228P-treated group. These evidences suggested that FcγRI+ binding and crosslinking had negative impact on the anti-PD-1 antibody-mediated anti-cancer activity.


Assuntos
Anticorpos Monoclonais/farmacologia , Carcinoma de Células Escamosas/imunologia , Imunoglobulina G/imunologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptores de IgG/metabolismo , Neoplasias Cutâneas/imunologia , Animais , Apoptose , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Proliferação de Células , Humanos , Imunoglobulina G/efeitos dos fármacos , Imunoglobulina G/metabolismo , Ativação Linfocitária , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Receptor de Morte Celular Programada 1/imunologia , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Células Tumorais Cultivadas , Microambiente Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Health Qual Life Outcomes ; 16(1): 43, 2018 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-29530024

RESUMO

BACKGROUND: A person's self-efficacy plays a critical role during the chronic management process of a health condition. Assessment of self-efficacy for patients with heart diseases is essential for healthcare professionals to provide tailored interventions to help patient to manage the disease. OBJECTIVE: To translate and test the psychometric properties of the Chinese version of Cardiac Self-efficacy Scale (C-CSES) as a disease-specific instrument for patients with coronary heart disease (CHD) in mainland China. METHODS: The original English version of the CSES was translated into Chinese using a forward-backward translation approach. A convenience sample consisting of 224 Chinese patients with CHD were recruited from a university-affiliated hospital in Shiyan, China. The C-CSES and the General Self-efficacy Scale (GSES) were used in this study. The factor structure, convergent and discriminative validities, and internal consistency of the C-CSES were evaluated. RESULTS: The confirmatory factor analysis (CFA) supported a three-factor high-order structure of the C-CSES with model fit indexes (RMSEA = 0.084, CFI = 0.954, NNFI = 0.927, IFI = 0.954 and χ 2 /df = 2.572). The C-CSES has good internal consistency with a Cronbach's alpha of 0.926. The convergent validity of the C-CSES was established with significantly moderate correlations between the C-CSES and the Chinese version of the GSES (p < 0.001). The C-CSES has also shown good discriminative validity with significant differences of cardiac self-efficacy being found between patients with and without comorbidities of hypertension, diabetes, or heart failure. CONCLUSION: The empirical data supported that the C-CSES is a valid and reliable disease-specific instrument for assessing the self-efficacy of Chinese patients with CHD.


Assuntos
Doença das Coronárias/psicologia , Qualidade de Vida , Autoeficácia , Idoso , China , Análise Fatorial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Reprodutibilidade dos Testes , Inquéritos e Questionários/normas , Traduções
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