Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Anal Biochem ; 660: 114971, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36328214

RESUMO

Exosome is an emerging tumor marker, whose concentration level can reflect the occurrence and development of tumors. The development of rapid and sensitive exosome detection platform is of great significance for early warning of cancer occurrence. Here, a strategy for electrochemical detection of A549-cell-derived exosomes was established based on DNA/ferrocene-modified single-walled carbon nanotube complex (DNA/SWCNT-Fc). DNA/SWCNT-Fc complexes function as a signal amplification platform to promote electron transfer between electrochemical signal molecules and electrodes, thereby improving sensitivity. At the same time, the exosomes can be attached to DNA/SWCNT-Fc nanocomposites via the established PO43--Ti4+-PO43- method. Moreover, the application of EGFR antibody, which can specifically capture A549 exosomes, could improve the accuracy of this sensing system. Under optimal experimental conditions, the biosensor showed good linear relationship between the peak current and the logarithm of exosomes concentration from 4.66 × 106 to 9.32 × 109 exosomes/mL with a detection limit of 9.38 × 104 exosomes/mL. Furthermore, this strategy provides high selectivity for exosomes of different cancer cells, which can be applied to the detection of exosomes in serum samples. Thus, owing to its advantages of high sensitivity and good selectivity, this method provides a diversified platform for exosomes identification and has great potential in early diagnosis and biomedical applications.


Assuntos
Exossomos , Nanotubos de Carbono , Metalocenos , DNA
2.
Sensors (Basel) ; 20(14)2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32650574

RESUMO

Intrusion detection is only the initial part of the security system for an industrial control system. Because of the criticality of the industrial control system, professionals still make the most important security decisions. Therefore, a simple intrusion alarm has a very limited role in the security system, and intrusion detection models based on deep learning struggle to provide more information because of the lack of explanation. This limits the application of deep learning methods to industrial control network intrusion detection. We analyzed the deep neural network (DNN) model and the interpretable classification model from the perspective of information, and clarified the correlation between the calculation process of the DNN model and the classification process. By comparing the normal samples with the abnormal samples, the abnormalities that occur during the calculation of the DNN model compared to the normal samples could be found. Based on this, a layer-wise relevance propagation method was designed to map the abnormalities in the calculation process to the abnormalities of attributes. At the same time, considering that the data set may already contain some useful information, we designed filtering rules for a kind of data set that can be obtained at a low cost, so that the calculation result is presented in a more accurate manner, which should help professionals lock and address intrusion threats more quickly.

3.
Ann Hematol ; 97(12): 2479-2490, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30078144

RESUMO

We describe the first multicenter prospective study to assess the efficacy, safety, and immune reconstitution of a novel sequential transplant approach in 24 patients with primary induction failure/relapsed acute myeloid leukemia (AML). The sequential regimen consisted of cladribine 5 mg/m2/day and cytarabine 2 g/m2/day for 5 days and mitoxantrone 7 mg/m2/day for 3 days, followed by myeloablative allogeneic hematopoietic stem cell transplantation (allo-HSCT) using intravenous busulfan (3.2 mg/kg/day) for 4 days and cyclophosphamide (60 mg/kg/day) for 2 days. Patients in CR without acute graft-versus-host disease at day + 90 received prophylactic donor lymphocyte infusion (pDLI). At the time of transplantation, a marrow blast infiltration > 20% or any level of circulating blasts was found in 62.5% of patients. The cumulative incidence of relapse at 2 years was 29.8%. Overall survival (OS) was 74.5% at 1 year and 56.5% at 2 years. Leukemia-free survival (LFS) at 1 and 2 years was 62.5 and 50.5%, respectively. Multivariate analysis demonstrated that haploidentical related donor, pDLI, and experiencing chronic graft-versus-host disease (cGVHD) were protective from relapse. Total T cells and T cell subsets in peripheral blood recovered at 3 months post-HSCT. The expressions of immune checkpoints (cytotoxic T lymphocyte antigen 4 and programmed death 1) were extremely low in T cells over the first 1 year post-transplantation.


Assuntos
Cladribina/administração & dosagem , Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/terapia , Transfusão de Linfócitos , Doadores de Tecidos , Doença Aguda , Adolescente , Adulto , Aloenxertos , Bussulfano/administração & dosagem , Criança , Ciclofosfamida/administração & dosagem , Intervalo Livre de Doença , Feminino , Doença Enxerto-Hospedeiro/sangue , Doença Enxerto-Hospedeiro/mortalidade , Doença Enxerto-Hospedeiro/prevenção & controle , Humanos , Leucemia Mieloide Aguda/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Taxa de Sobrevida
4.
Eur J Haematol ; 100(6): 624-629, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29532539

RESUMO

OBJECTIVES: In patients with very severe aplastic anemia (VSAA), neutropenia is prolonged and persistent, resulting in refractory overwhelming infections. Hematopoiesis recovery is urgently needed. METHODS: Six patients with de novo VSAA lacking HLA-identical sibling donors and those who experienced refractory infections underwent haploidentical related donor (HRD) hematopoietic stem cell transplantation (HSCT) as a first-line therapy. The conditioning regimen consisted of busulfan, cyclophosphamide, and rabbit antithymocyte globulin. Culture-expanded allogeneic bone marrow-derived mesenchymal stromal cells were infused on day 0 and day +14. RESULTS: From diagnosis to HSCT, 6 patients experienced a total of 28 episodes of persistent fever, and the median number was 4 (range, 3-7). All cases developed major bacterial infections and invasive pulmonary fungal infection pre-HSCT. The median time from diagnosis to HSCT was 2 months (range, 1-3.5 months). All patients achieved sustained, full donor chimerism, and the median time of myeloid recovery and platelet engraftment was 13 days (range, 9-19 days) and 15.5 days (range, 10-23 days), respectively. One patient died of aGVHD, and 5 patients are alive after a median follow-up of 21 months (range 17-40.5). CONCLUSIONS: Upfront HRD-HSCT may be a safe and promising choice for patients with VSAA in critical situations without suitably matched donors.


Assuntos
Anemia Aplástica/diagnóstico , Anemia Aplástica/terapia , Transplante de Células-Tronco Hematopoéticas , Transplante de Células-Tronco Mesenquimais , Adolescente , Adulto , Anemia Aplástica/complicações , Biomarcadores , Terapia Combinada , Feminino , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Infecções/diagnóstico , Infecções/etiologia , Masculino , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Índice de Gravidade de Doença , Condicionamento Pré-Transplante , Transplante Homólogo , Resultado do Tratamento , Adulto Jovem
5.
J Stroke Cerebrovasc Dis ; 27(11): 3076-3083, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30077605

RESUMO

BACKGROUND: Epidemiologic studies have indicated conflicting associations of fibroblast growth factor-23 (FGF23) with the risk of stroke. To this end, a meta-analysis of prospective studies was conducted to assess the association. METHODS: Relevant studies were identified by searching PubMed and Embase databases to March 23, 2018. Relative risks (RRs) with 95% confidence intervals (CIs) were combined with the fixed-effects model or random-effects model according to the degree of heterogeneity. Moreover, stratified analyses and sensitivity analysis were carried out for further analysis. RESULTS: Seven prospective studies involving 1988 stroke events among 18048 participants were eligible for our meta-analysis. The combined RRs for total stroke were 1.29 (95% CI: 1.10, 1.52) for the highest versus lowest category of FGF23, with low heterogeneity among studies (Pheterogeneity = 0.38, I2 = 6.1%). Stratified analyses showed that the combined RRs for ischemic stroke (IS) and hemorrhagic stroke (HS) risk were 1.12 (95% CI: 0.92, 1.37) and 2.63 (95% CI: 1.61, 4.30), respectively. In the stratification by geographic areas, the association between higher FGF23 and stroke was similar with studies performed in the United States (RR = 1.24, 95%CI: 1.03, 1.49) and Europe (RR = 1.88, 95%CI: 0.77, 4.55); however, only the results in the United States were statistically significant. Sensitivity analysis indicated the combined results were robust. CONCLUSIONS: Our meta-analysis showed that higher FGF23 levels were associated with an increased risk of stroke. The positive association consistently existed in HS rather than in IS. Further studies are required to confirm these causal associations and to investigate the mechanisms.


Assuntos
Isquemia Encefálica/sangue , Isquemia Encefálica/epidemiologia , Fatores de Crescimento de Fibroblastos/sangue , Hemorragias Intracranianas/sangue , Hemorragias Intracranianas/epidemiologia , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/epidemiologia , Biomarcadores/sangue , Isquemia Encefálica/diagnóstico , Fator de Crescimento de Fibroblastos 23 , Humanos , Hemorragias Intracranianas/diagnóstico , Prognóstico , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico , Regulação para Cima
6.
Tumour Biol ; 35(6): 5869-76, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24664582

RESUMO

In this study, we explored the relationship between neutropenia (absolute neutrophil count (ANC) <1,500/mm(3)) and invasive fungal infection (IFI) in Chinese patients who had hematological malignancies treated with chemotherapy. We conducted a multicenter, prospective, non-interventional study of consecutive patients with hematological malignancies undergoing chemotherapy in China and determined clinical characteristics of patients who developed neutropenia and IFI. The results indicated that for the 2,177 neutropenic patients, 88 (4.0 %) were diagnosed with IFI. We found that a high risk of IFI (P<0.05) is associated with male gender, non-remission of the primary disease, use of two or more broad-spectrum antibiotics, treatment with parenteral nutrition, presence of cardiovascular disease, history of IFI, and neutropenia. When the ANC was less than 1,000, 1,000∼500, 500∼100, and <100/mm(3), the incidence of IFI was 0.5, 5.2, 3.9, and 4.7 %, respectively (ANC>1,000/mm(3) versus other groups, P<0.001). When the ANC was less than 1,000, 500, or 100/mm(3) for 10 days or more, the incidence of IFI was 3.2 versus 6.1 % (P=0.0052), 3.5 versus 7.1 % (P=0.0021), and 3.1 versus 10.0 % (P<0.001). When the ANC was less than 100/mm(3), taking antifungal prophylaxis reduced the incidence of IFI (P<0.05). The IFI-attributable mortality rate was 11.7 %. In conclusion, Chinese patients with IFI, severe and prolonged neutropenia increases the incidence of IFI. The incidence of IFI associated with neutropenia was reduced when antifungal prophylaxis was given. IFI was associated with a significantly increased high mortality rate in hematological malignancy patients with neutropenia.


Assuntos
Neoplasias Hematológicas/tratamento farmacológico , Micoses/etiologia , Neutropenia/complicações , Adulto , Idoso , Antifúngicos/uso terapêutico , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Micoses/prevenção & controle , Estudos Prospectivos , Fatores de Risco
7.
Sci Rep ; 14(1): 7106, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38532061

RESUMO

In situ high-pressure/high-temperature Raman-scattering analyses on PbTiO 3 , 0.92PbTiO 3 - 0.08Bi(Zn 0.5 Ti 0.5 )O 3 and 0.83PbTiO 3 - 0.17Bi(Mg 0.5 Ti 0.5 )O 3 single crystals reveal an intensity transfer between the fine-structure components of the A 1 (TO) soft mode. The enhancement of the lowest-energy subpeak, which stems from intrinsic local non-tetragonal polar distortions, along with the suppression of the tetragonal A 1 (1TO) fundamental mode with increasing pressure and temperature indicates the key role of the local polarization fluctuations in transformation processes and emphasizes the significance of the order-disorder phenomena in both the pressure- and temperature-induced phase transitions of pure PbTiO 3 and its solid solutions with complex perovskites. Moreover, the temperature and pressure evolution of the fraction of the local non-tetragonal polar distortions is highly sensitive to the type of B-site substituent.

8.
Sci Data ; 11(1): 571, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38834588

RESUMO

Chip is a visual representation of rock breaking by cutter, and their related parameters are crucial for revealing the rock breaking mechanism in deep-sea mining. Based on sieving and three-dimensional size measurement methods widely used in mining engineering, this paper reports a dataset of chip parameters for rock breaking by chisel pick under deep-sea hydrostatic pressure. Specifically, we first designed an experimental setup that can accurately simulate deep-sea hydrostatic pressure, conducted rock breaking experiments and carefully collected chips. Subsequently, those chips were sieved, high-resolution images were collected, and the coarseness index (CI), chip size uniformity (n), absolute chip size (de), and fractal dimension (D) were measured. Finally, three-dimensional size (long, intermediate and short) was measured for 3064 chips with particle sizes greater than 4.75 mm. This dataset will be used by researchers to validate numerical simulations or optimize equipment structures related to deep-sea mining, including deep-sea rock mechanics, mining cutter and conveyor pipes.

9.
Front Immunol ; 15: 1321236, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38380312

RESUMO

During the COVID-19 pandemic, elderly patients with underlying condition, such as tumors, had poor prognoses after progressing to severe pneumonia and often had poor response to standard treatment. Mesenchymal stem cells (MSCs) may be a promising treatment for patients with severe pneumonia, but MSCs are rarely used for patients with carcinoma. Here, we reported a 67-year-old female patient with lung adenocarcinoma who underwent osimertinib and radiotherapy and suffered from radiation pneumonitis. Unfortunately, she contracted COVID-19 and that rapidly progressed to severe pneumonia. She responded poorly to frontline treatment and was in danger. Subsequently, she received a salvage treatment with four doses of MSCs, and her symptoms surprisingly improved quickly. After a lung CT scan that presented with a significantly improved infection, she was discharged eventually. Her primary disease was stable after 6 months of follow-up, and no tumor recurrence or progression was observed. MSCs may be an effective treatment for hyperactive inflammation due to their ability related to immunomodulation and tissue repair. Our case suggests a potential value of MSCs for severe pneumonia that is unresponsive to conventional therapy after a COVID-19 infection. However, unless the situation is urgent, it needs to be considered with caution for patients with tumors. The safety in tumor patients still needs to be observed.


Assuntos
COVID-19 , Neoplasias Pulmonares , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Pneumonite por Radiação , Humanos , Feminino , Idoso , COVID-19/etiologia , SARS-CoV-2 , Neoplasias Pulmonares/etiologia , Pneumonite por Radiação/etiologia , Pneumonite por Radiação/terapia , Pandemias , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Recidiva Local de Neoplasia
10.
Gene ; 911: 148320, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38452876

RESUMO

BACKGROUND: Non-Hodgkin's lymphoma incidence rates vary between European and Asian populations. The reasons remain unclear. This two-sample two-step Mendelian randomisation (MR) study aimed to investigate the causal relationship between anthropometric indicators (AIs) and diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) and the possible mediating role of basal metabolic rate (BMR) in Europe. METHODS: We used the following AIs as exposures: body mass index (BMI), whole-body fat mass (WBFM), whole-body fat-free mass (WBFFM), waist circumference(WC), hip circumference(HC), standing height (SH), and weight(Wt). DLBCL and FL represented the outcomes, and BMR was a mediator. A two-sample MR analysis was performed to examine the association between AIs and DLBCL and FL onset. We performed reverse-MR analysis to determine whether DLBCL and FL interfered with the AIs. A two-step MR analysis was performed to determine whether BMR mediated the causality. FINDINGS: WBFFM and SH had causal relationships with FL. A causal association between AIs and DLBCL was not observed. Reverse-MR analysis indicated the causal relationships were not bidirectional. Two-step MR suggested BMR may mediate the causal effect of WBFFM and SH on FL. CONCLUSIONS: We observed a causal relationship between WBFFM and SH and the onset of FL in Europeans, Which may explain the high incidence of follicular lymphoma in Europeans.


Assuntos
Linfoma Folicular , Linfoma Difuso de Grandes Células B , Humanos , Índice de Massa Corporal , Europa (Continente)/epidemiologia , Incidência , Linfoma Folicular/epidemiologia , Linfoma Folicular/genética , Linfoma Folicular/patologia , Análise da Randomização Mendeliana
11.
Sci Rep ; 13(1): 10474, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37380649

RESUMO

To study the mechanism and performance of rock breakage by an undercutting disc cutter with advanced slotting, a three-dimensional numerical model of rock cutting by a disc cutter with advanced slotting assistance was established based on the discrete element method. The parallel bond constitutive model was selected to describe the micromechanical properties of rock. The correctness of the established numerical model is verified through rock breakage experiments, and the rock cutting process by the disc cutter was analyzed by a combination of the force chain and crack distribution. The influencing factors, such as advanced slotting depth, cutting thickness, rock strength, and cutter rotation speed, on rock cutting performance were investigated. The results show that a compact zone is gradually formed between the rock and disc cutter at the beginning, then a large number of microscopic tensile and shear cracks in the compact zone due to micro failure of rock are formed; the subsequent main rock fragment is mainly caused by tensile failure; advanced slotting can reduce the rock bearing capacity and bending resistance, the rock above the advanced slotting fractured easily due to its lower bending resistance, and the volume compact zone is relatively small. When the advanced slotting depth is equal to 12.5 mm, the propulsive force and specific energy consumption of rock cutting by the disc cutter are reduced by 61.6% and 16.5%, respectively. The propulsive force and specific energy consumption increase as the rock strength increases, but they tend to close when the rock strength is greater than 80 MPa, which indicates that advanced slotting assistance is more suitable for hard rock. The results obtained in this paper can provide the operating parameters determination under different factors to some extent of the undercutting disc cutter in a pre-cut condition, which further improve the rock breaking performance of mechanized cutter.

12.
Nanoscale Horiz ; 8(8): 1113-1121, 2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37326422

RESUMO

Two dimensional (2D) metal-semiconductor heterostructures are promising for high-performance optoelectronic devices due to fast carrier separation and transportation. Considering the superior metallic characteristics accompanied by high electrical conductivity in NbSe2, surface oxidation provides a facile way to form NbSe2/Nb2O5 metal-semiconductor heterostructures. Herein, size-dependent NbSe2/Nb2O5 nanosheets were achieved by a liquid phase exfoliation method and a gradient centrifugation strategy. These NbSe2/Nb2O5 heterostructure-based photodetectors show high responsivity with 23.21 µA W-1, fast response time of millisecond magnitude, and wide band detection ability in the UV-Vis region. It is noticeable that the photocurrent density is sensitive to the surface oxygen layer due to the oxygen-sensitized photoconduction mechanism. The flexible testing of the NbSe2/Nb2O5 heterostructure-based PEC-type photodetectors exhibits high photodetection performance even after bending and twisting. Beyond that, the solid-state PEC-type NbSe2/Nb2O5 photodetector also achieves relatively stable photodetection and high stability. This work promotes the application of 2D NbSe2/Nb2O5 metal-semiconductor heterostructures in flexible optoelectronic devices.

13.
Front Psychiatry ; 14: 1291988, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38130293

RESUMO

Background: Sexual dysfunction is commonly observed in individuals with Major Depressive Disorder (MDD), along with various psychological symptoms such as anxiety, somatic complaints, interpersonal sensitivity, and obsessive-compulsive tendencies. However, there is a research gap in understanding the impact of these psychological symptoms on sexual functioning in MDD. Furthermore, there is limited data on the incidence of sexual dysfunction among drug-naive MDD patients in West China. This study aims to determine the prevalence of sexual dysfunction in this patient population and explore its association with other psychological indicators. Methods: We conducted a retrospective analysis of patient data from October 2020 to September 2022 using propensity score matching. A focused group of 165 males and 490 females was selected from a total of 1941 MDD patients. This allowed for a comparative analysis of demographic data, as well as scores from the Self-Rating Depression Scale (SDS), Self-Rating Anxiety Scale (SAS), and Symptom Checklist-90 (SCL-90), the Arizona Sexual Experience Scale (ASEX). Results: Our findings reveal that 46.2% of drug-naive MDD patients experienced sexual dysfunction. Notably, there was a higher prevalence of sexual dysfunction among female patients (50.3%) compared to males (37.5%). MDD patients without sexual dysfunction consistently exhibited higher SDS scores than those with sexual dysfunction (p < 0.01), There were no statistically significant differences between male and female MDD patients with or without concomitant sexual dysfunction in terms of Somatic complaints, Obsessive-compulsive, Interpersonal sensitivity, Anxiety, Phobic anxiety, Paranoid ideation, Psychoticism and Diet/sleep difficulties (p > 0.05). In addition, male MDD patients with sexual dysfunction showed a emerging trend towards elevated Hostility scores on the SCL-90 (p = 0.058), male MDD patients with sexual dysfunction showed an increasing trend in hostility scores on the SCL-90, whereas female MDD patients with sexual dysfunction did not show such a trend. Conclusion: The study highlights a significant gender difference in the prevalence of sexual dysfunction among MDD patients, with females being more susceptible than males. There is a positive correlation between the severity of depression and sexual dysfunction in both genders. Interestingly, male MDD patients demonstrated a potential protective effect of hostility against sexual dysfunction, which was not observed in female patients.

14.
Redox Rep ; 28(1): 2225868, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37439434

RESUMO

BACKGROUND: Acquired aplastic anemia (AA) is a life-threatening disease associated with an imbalance in Th17/Treg cells. Regulating this balance may be an effective treatment approach for AA. Rhodiola rosea has shown efficacy in AA treatment, but its mechanisms remain unclear. PURPOSE: We investigated salidroside's effect (a component of Rhodiola rosea) on Th17/Treg balance in adult AA patients and a mouse model. METHODS: HIF-1α mRNA and protein levels were measured in AA patients' peripheral blood. Flow cytometry, qRT-PCR, and WB analyzed salidroside's impact on T cell differentiation, Th17 cells, Treg cells, STAT3, HIF-1α, and RORγt expression. ELISA measured hematopoietic growth factors in mouse serum. RESULTS: AA patients exhibited elevated HIF-1α levels. Salidroside improved hematopoietic function, increasing blood cell count and enhancing bone marrow. Salidroside induced SCF, TPO, and IL-3 expression while inhibiting IL-2 in mice. Salidroside reduced STAT3, HIF-1α, RORγt, and IL-17a, while increasing FoxP3 expression, correcting the Th17/Treg imbalance in vitro and in vivo. CONCLUSION: Salidroside has potential as a novel AA treatment by correcting the Th17/Treg imbalance through the STAT3/HIF-1α/RORγt pathway.


Assuntos
Anemia Aplástica , Glucosídeos , Linfócitos T Reguladores , Animais , Camundongos , Anemia Aplástica/tratamento farmacológico , Glucosídeos/farmacologia , Glucosídeos/uso terapêutico , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Humanos , Fator de Transcrição STAT3 , Subunidade alfa do Fator 1 Induzível por Hipóxia , Células Th17
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 280: 121535, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-35752041

RESUMO

In this work, a novel fluorescent biosensor for sensitive detecting of aflatoxin B1 (AFB1) was constructed through activators regenerated by electron transfer for atom transfer radical polymerization (ARGET-ATRP) for the first time. The AFB1 antigen was immobilized on the carboxy magnetic beads (MBs) by forming a sandwich-type "aptamer-antigen-antibody" immune system. Then, acrylamid (AM) was introduced through ARGET-ATRP to provide binding sites for the signaling molecules. Finally, carboxy porphyrins (TPP*) were connected with monomers through an amide bond and fixed on the MBs. Under the optimal experimental conditions, the fluorescence intensity and the logarithm of the concentration of AFB1 showed a good relationship from 100 fg mL-1 to 100 ng mL-1, with the limit of detection (LOD) as low as 8.38 fg mL-1. In addition, the method shows good selectivity and excellent reproducibility. More importantly, the biosensor has applied to the quantitative analysis of AFB1 in four Chinese medicines, and this strategy could potentially serve as a novel means for sensitive detecting of AFB1 in complex matrices.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Porfirinas , Aflatoxina B1/análise , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Limite de Detecção , Polimerização , Reprodutibilidade dos Testes
16.
Am J Infect Control ; 50(10): 1171-1177, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35108580

RESUMO

OBJECTIVES: We sought to investigate the nature and incidence of bloodstream infection complications and to identify the risk factors of central catheter-related bloodstream infections (CRBSI). METHODS: During the study period, 291 consecutive patients with hematological malignancies who underwent PICC placement were retrospectively enrolled. We analyzed the covariates that were specified a priori for their association with CRBSI through multivariate Cox proportional hazards regression models. The association between each predictor and the related outcome was expressed using hazard ratios (HRs) with corresponding 95% confidence intervals (CIs). RESULTS: Of 391 peripherally inserted central catheter (PICCs) were inserted in 291 patients for a total of 63,714 catheter days during 7 years, with an infection rate of 0.71/1,000 catheter days. Among the patients with hematological malignancies, those with acute leukemia were prone to CRBSI. Having previous bloodstream infection (BSI) (HR 18.139; 95% CI, 8.19-40.174; P < .0001), the number of PICCs insertions (HR 4.695; 95% CI, 1.842-11.967; P = .001) (twice), (HR 6.794; 95% CI, 1.909-24.181; P = .003) (≥3 times) were significantly associated with CRBSI. Not accompanied by chronic comorbidities (HR 0.34; 95% CI, 0.131-0.887; P = .028) and longer duration of PICC use (days) (HR 0.997; 95% CI, 0.994-0.999; P = .008) might be protective factors preventing CRBSI. CONCLUSIONS: Our finding suggests that previous BSI and a higher number of PICC insertions are associated with an increased risk of CRBSI. A lack of chronic comorbidities may help prevent CRBSI.


Assuntos
Infecções Relacionadas a Cateter , Cateterismo Venoso Central , Cateterismo Periférico , Cateteres Venosos Centrais , Neoplasias Hematológicas , Sepse , Infecções Relacionadas a Cateter/epidemiologia , Infecções Relacionadas a Cateter/etiologia , Cateterismo Venoso Central/efeitos adversos , Cateterismo Periférico/efeitos adversos , Catéteres , Cateteres Venosos Centrais/efeitos adversos , Neoplasias Hematológicas/complicações , Humanos , Estudos Retrospectivos , Fatores de Risco , Sepse/etiologia
17.
Biophys J ; 101(4): 885-91, 2011 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-21843479

RESUMO

The measurement of polymer growth is an essential element in characterization of assembly. We have developed a precise method of measuring the growth of sickle hemoglobin polymers by observing the time required for polymers to traverse a photolytically produced channel between a region in which polymers are created and a detection region. The presence of the polymer is functionally detected by observing its ability to create new polymers through the well-established process of heterogeneous nucleation. Using this method, we have determined the rate constants for monomer addition to and release from polymer ends, as well as their temperature dependences. At 25°C we find k(+) = 84 ± 2 mM⁻¹ s⁻¹ and k(-) = 790 ± 80 molecules/s from each end. These numbers are in accord with differential interference contrast measurements, and their ratio gives a solubility measured on individual fibers. The single-fiber solubility agrees with that measured in sedimentation experiments. The concentration dependence of the monomer addition rate is consistent with monomer addition, but not oligomer addition, to growing polymers. The concentration dependence suggests the presence of an activation enthalpy barrier, and the rate of monomer addition is not diffusion-limited. Analysis of the temperature dependence of the monomer addition rate reveals an apparent activation energy of 9.1 ± 0.6 kcal/mol.


Assuntos
Biopolímeros/química , Hemoglobina Falciforme/química , Difusão/efeitos da radiação , Humanos , Cinética , Luz , Fotólise/efeitos da radiação , Temperatura , Fatores de Tempo
18.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 28(4): 795-9, 2011 Aug.
Artigo em Zh | MEDLINE | ID: mdl-21936383

RESUMO

The aim of this research was to explore the most optimal method of DNA extraction from formalin-fixed, paraffin-embedded (FFPE) tissues, and to improve the amplification of long fragments with the method. Three methods, one step method, phenol-chloroform extraction method, and genomic DNA purification kit method, were employed to extract DNA from twenty normal thyroid tissues which were fixed with formalin and embedded with paraffin. The highest proportionality of OD260/OD280 in the examples was obtained by phenol-chloroform extraction method, 1.703 +/- 0.086, compared to the results of the other two methods. As for the long DNA segments amplification, the achievement ratio of one step method, phenol-chloroform extraction method and genomic DNA purification kit method were 0%, 5% and 10%, respectively, by traditional PCR method, but 0%, 95% and 85% respectively by the nest PCR. We have found that the best process of extracting DNA from FFPE is digesting by proteinase K and purifying by phenol-chloroform, and it is effective to amplify long DNA segments from FFPE by nest PCR.


Assuntos
DNA/isolamento & purificação , Inclusão em Parafina , Patologia Molecular/métodos , Reação em Cadeia da Polimerase/métodos , Glândula Tireoide/patologia , Sequência de Bases , Formaldeído , Humanos , Dados de Sequência Molecular , Sensibilidade e Especificidade , Fixação de Tecidos
19.
Talanta ; 233: 122531, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215034

RESUMO

Exosomes, as a biomarker with enhancing tumor invasion and spread, play an essential role for lung cancer diagnosis, therapy, and prognosis. In this work, a novel electrochemical sensor was fabricated for detecting exosomes secreted by lung cancer cells based on polysaccharide-initiated ring-opening polymerization (ROP) and click polymerization. First, MPA formed a self-assembled monolayer on the gold electrode surface, and then anti-EGFR was immobilized on the electrode surface by amide bond. Subsequently, a lot of phosphate groups were introduced by the specific recognition between anti-EGFR and exosomes, then sodium alginate grafted Glycidyl propargyl ether (SA-g-GPE) prepared via ROP was attached to the exosomes through PO43-Zr4+-COOH coordination bond. After that, click polymerization was initiated by alkyne groups on the SA-g-GPE polymerization chain to realize highly sensitive detection of A549 exosomes. Under the optimum conditions, the fabricated sensor showed a good linear relationship between the logarithm of exosomes concentration and peak current in the range of 5 × 103 - 5 × 109 particles/mL, and the limit of detection (LOD) was as low as 1.49 × 102 particles/mL. In addition, this method had the advantages of high specificity, anti-interference, high sensitivity, simplicity, rapidity and green economy, which proposed a novel avenue for the detection of exosomes, and also had potential applications in early cancer diagnosis and biomedicine.


Assuntos
Técnicas Biossensoriais , Exossomos , Técnicas Eletroquímicas , Ouro , Limite de Detecção , Polimerização , Polissacarídeos
20.
Food Funct ; 12(20): 9922-9931, 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34492673

RESUMO

Theaflavins (TFs) are the characteristic components of black tea and have been widely acknowledged for their health benefits. The current study aimed to investigate the effects and mechanism of TFs, TF1, TF2a and TF3 on glycolipid metabolism in obese mice induced by a high-fat diet (HFD). Mice were randomly divided into seven groups (n = 8 per group) as follows: low-fat diet (LFD), HFD, HFD + metformin (Met, 100 mg kg-1 d-1), HFD + TFs (TFs, 200 mg kg-1 d-1), HFD + TF1 (TF1, 100 mg kg-1 d-1), HFD + TF2a (TF2a, 100 mg kg-1 d-1), and HFD + TF3 (TF3, 100 mg kg-1 d-1). All groups were studied for 9 weeks continuously. The levels of serum glucose, insulin, TC, TG, LDL and HLD in the plasma, lipid accumulation in the liver, and injury of the liver were investigated. In addition, the effects of TFs and their monomers on the SIRT6/AMPK/SREBP-1/FASN pathway were also evaluated. The results showed that oral administration of TFs, TF1, TF2a and TF3 not only dramatically suppressed weight gain, reduced blood glucose level, and ameliorated insulin resistance but also obviously lowered the levels of serum TC, TG and LDL, suppressed the activities of ALT and AST, and ameliorated hepatic damage in mice fed a HFD when compared to the HFD group. Western blot analysis showed that TFs, TF1, TF2a and TF3 treatments increased the expression of SIRT6 and suppressed the expression levels of SREBP-1 and FASN significantly in mice fed a HFD as compared to the HFD group. The phosphorylation of AMPK in mice fed a HFD was obviously elevated by TF2a and TF3 when compared to the HFD group. These results proved for the first time that TF1, TF2a and TF3 improved the glucolipid metabolism of mice fed a HFD, and activated the SIRT6/AMPK/SREBP-1/FASN signaling pathway to inhibit the synthesis and accumulation of lipids in the liver to ameliorate obesity in mice fed a HFD. These findings indicate that TFs, TF1, TF2a and TF3 as the main functional components of black tea might potentially be used as a food additive for improving glycolipid metabolism and ameliorating obesity, and TF3 may be the best choice.


Assuntos
Biflavonoides/farmacologia , Catequina/farmacologia , Hipoglicemiantes/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Obesidade/tratamento farmacológico , Quinases Proteína-Quinases Ativadas por AMP/metabolismo , Animais , Glicemia/análise , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Dieta Hiperlipídica/efeitos adversos , Resistência à Insulina , Fígado/metabolismo , Masculino , Metformina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/metabolismo , Sirtuínas/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Chá/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA